1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
|
<!DOCTYPE html>
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>PHP Style Guide — CodeIgniter 3.1.10 documentation</title>
<link rel="shortcut icon" href="../_static/ci-icon.ico"/>
<link href='https://fonts.googleapis.com/css?family=Lato:400,700,400italic,700italic|Roboto+Slab:400,700|Inconsolata:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>
<link rel="stylesheet" href="../_static/css/citheme.css" type="text/css" />
<link rel="index" title="Index"
href="../genindex.html"/>
<link rel="search" title="Search" href="../search.html"/>
<link rel="top" title="CodeIgniter 3.1.10 documentation" href="../index.html"/>
<link rel="up" title="General Topics" href="index.html"/>
<link rel="next" title="Libraries" href="../libraries/index.html"/>
<link rel="prev" title="Security" href="security.html"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/modernizr/2.6.2/modernizr.min.js"></script>
</head>
<body class="wy-body-for-nav" role="document">
<div id="nav">
<div id="nav_inner">
<div id="pulldown-menu" class="ciNav">
<ul>
<li class="toctree-l1"><a class="reference internal" href="welcome.html">Welcome to CodeIgniter</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../installation/index.html">Installation Instructions</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../installation/downloads.html">Downloading CodeIgniter</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/index.html">Installation Instructions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/upgrading.html">Upgrading From a Previous Version</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/troubleshooting.html">Troubleshooting</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../overview/index.html">CodeIgniter Overview</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../overview/getting_started.html">Getting Started</a></li>
<li class="toctree-l2"><a class="reference internal" href="../overview/at_a_glance.html">CodeIgniter at a Glance</a></li>
<li class="toctree-l2"><a class="reference internal" href="../overview/features.html">Supported Features</a></li>
<li class="toctree-l2"><a class="reference internal" href="../overview/appflow.html">Application Flow Chart</a></li>
<li class="toctree-l2"><a class="reference internal" href="../overview/mvc.html">Model-View-Controller</a></li>
<li class="toctree-l2"><a class="reference internal" href="../overview/goals.html">Architectural Goals</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../tutorial/index.html">Tutorial</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/static_pages.html">Static pages</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/news_section.html">News section</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/create_news_items.html">Create news items</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/conclusion.html">Conclusion</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../contributing/index.html">Contributing to CodeIgniter</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../documentation/index.html">Writing CodeIgniter Documentation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../DCO.html">Developer’s Certificate of Origin 1.1</a></li>
</ul>
</li>
</ul>
<ul class="current">
<li class="toctree-l1 current"><a class="reference internal" href="index.html">General Topics</a><ul class="current">
<li class="toctree-l2"><a class="reference internal" href="urls.html">CodeIgniter URLs</a></li>
<li class="toctree-l2"><a class="reference internal" href="controllers.html">Controllers</a></li>
<li class="toctree-l2"><a class="reference internal" href="reserved_names.html">Reserved Names</a></li>
<li class="toctree-l2"><a class="reference internal" href="views.html">Views</a></li>
<li class="toctree-l2"><a class="reference internal" href="models.html">Models</a></li>
<li class="toctree-l2"><a class="reference internal" href="helpers.html">Helpers</a></li>
<li class="toctree-l2"><a class="reference internal" href="libraries.html">Using CodeIgniter Libraries</a></li>
<li class="toctree-l2"><a class="reference internal" href="creating_libraries.html">Creating Libraries</a></li>
<li class="toctree-l2"><a class="reference internal" href="drivers.html">Using CodeIgniter Drivers</a></li>
<li class="toctree-l2"><a class="reference internal" href="creating_drivers.html">Creating Drivers</a></li>
<li class="toctree-l2"><a class="reference internal" href="core_classes.html">Creating Core System Classes</a></li>
<li class="toctree-l2"><a class="reference internal" href="ancillary_classes.html">Creating Ancillary Classes</a></li>
<li class="toctree-l2"><a class="reference internal" href="hooks.html">Hooks - Extending the Framework Core</a></li>
<li class="toctree-l2"><a class="reference internal" href="autoloader.html">Auto-loading Resources</a></li>
<li class="toctree-l2"><a class="reference internal" href="common_functions.html">Common Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="compatibility_functions.html">Compatibility Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="routing.html">URI Routing</a></li>
<li class="toctree-l2"><a class="reference internal" href="errors.html">Error Handling</a></li>
<li class="toctree-l2"><a class="reference internal" href="caching.html">Caching</a></li>
<li class="toctree-l2"><a class="reference internal" href="profiling.html">Profiling Your Application</a></li>
<li class="toctree-l2"><a class="reference internal" href="cli.html">Running via the CLI</a></li>
<li class="toctree-l2"><a class="reference internal" href="managing_apps.html">Managing your Applications</a></li>
<li class="toctree-l2"><a class="reference internal" href="environments.html">Handling Multiple Environments</a></li>
<li class="toctree-l2"><a class="reference internal" href="alternative_php.html">Alternate PHP Syntax for View Files</a></li>
<li class="toctree-l2"><a class="reference internal" href="security.html">Security</a></li>
<li class="toctree-l2 current"><a class="current reference internal" href="#">PHP Style Guide</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../libraries/index.html">Libraries</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../libraries/benchmark.html">Benchmarking Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/caching.html">Caching Driver</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/calendar.html">Calendaring Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/cart.html">Shopping Cart Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/config.html">Config Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/email.html">Email Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/encrypt.html">Encrypt Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/encryption.html">Encryption Library</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/file_uploading.html">File Uploading Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/form_validation.html">Form Validation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/ftp.html">FTP Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/image_lib.html">Image Manipulation Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/input.html">Input Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/javascript.html">Javascript Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/language.html">Language Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/loader.html">Loader Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/migration.html">Migrations Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/output.html">Output Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/pagination.html">Pagination Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/parser.html">Template Parser Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/security.html">Security Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/sessions.html">Session Library</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/table.html">HTML Table Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/trackback.html">Trackback Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/typography.html">Typography Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/unit_testing.html">Unit Testing Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/uri.html">URI Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/user_agent.html">User Agent Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/xmlrpc.html">XML-RPC and XML-RPC Server Classes</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/zip.html">Zip Encoding Class</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../database/index.html">Database Reference</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../database/examples.html">Quick Start: Usage Examples</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/configuration.html">Database Configuration</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/connecting.html">Connecting to a Database</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/queries.html">Running Queries</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/results.html">Generating Query Results</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/helpers.html">Query Helper Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/query_builder.html">Query Builder Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/transactions.html">Transactions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/metadata.html">Getting MetaData</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/call_function.html">Custom Function Calls</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/caching.html">Query Caching</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/forge.html">Database Manipulation with Database Forge</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/utilities.html">Database Utilities Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/db_driver_reference.html">Database Driver Reference</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../helpers/array_helper.html">Array Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/captcha_helper.html">CAPTCHA Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/cookie_helper.html">Cookie Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/date_helper.html">Date Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/directory_helper.html">Directory Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/download_helper.html">Download Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/email_helper.html">Email Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/file_helper.html">File Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/form_helper.html">Form Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/html_helper.html">HTML Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/inflector_helper.html">Inflector Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/language_helper.html">Language Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/number_helper.html">Number Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/path_helper.html">Path Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/security_helper.html">Security Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/smiley_helper.html">Smiley Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/string_helper.html">String Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/text_helper.html">Text Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/typography_helper.html">Typography Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/url_helper.html">URL Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/xml_helper.html">XML Helper</a></li>
</ul>
</li>
</ul>
</div>
</div>
</div>
<div id="nav2">
<a href="#" id="openToc">
<img src="data:image/jpeg;base64,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" title="Toggle Table of Contents" alt="Toggle Table of Contents" />
</a>
</div>
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-nav-search">
<a href="../index.html" class="fa fa-home"> CodeIgniter</a>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
<input type="text" name="q" placeholder="Search docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
</div>
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
<ul>
<li class="toctree-l1"><a class="reference internal" href="welcome.html">Welcome to CodeIgniter</a></li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../installation/index.html">Installation Instructions</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../installation/downloads.html">Downloading CodeIgniter</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/index.html">Installation Instructions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/upgrading.html">Upgrading From a Previous Version</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/troubleshooting.html">Troubleshooting</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../overview/index.html">CodeIgniter Overview</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../overview/getting_started.html">Getting Started</a></li>
<li class="toctree-l2"><a class="reference internal" href="../overview/at_a_glance.html">CodeIgniter at a Glance</a></li>
<li class="toctree-l2"><a class="reference internal" href="../overview/features.html">Supported Features</a></li>
<li class="toctree-l2"><a class="reference internal" href="../overview/appflow.html">Application Flow Chart</a></li>
<li class="toctree-l2"><a class="reference internal" href="../overview/mvc.html">Model-View-Controller</a></li>
<li class="toctree-l2"><a class="reference internal" href="../overview/goals.html">Architectural Goals</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../tutorial/index.html">Tutorial</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/static_pages.html">Static pages</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/news_section.html">News section</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/create_news_items.html">Create news items</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/conclusion.html">Conclusion</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../contributing/index.html">Contributing to CodeIgniter</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../documentation/index.html">Writing CodeIgniter Documentation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../DCO.html">Developer’s Certificate of Origin 1.1</a></li>
</ul>
</li>
</ul>
<ul class="current">
<li class="toctree-l1 current"><a class="reference internal" href="index.html">General Topics</a><ul class="current">
<li class="toctree-l2"><a class="reference internal" href="urls.html">CodeIgniter URLs</a></li>
<li class="toctree-l2"><a class="reference internal" href="controllers.html">Controllers</a></li>
<li class="toctree-l2"><a class="reference internal" href="reserved_names.html">Reserved Names</a></li>
<li class="toctree-l2"><a class="reference internal" href="views.html">Views</a></li>
<li class="toctree-l2"><a class="reference internal" href="models.html">Models</a></li>
<li class="toctree-l2"><a class="reference internal" href="helpers.html">Helpers</a></li>
<li class="toctree-l2"><a class="reference internal" href="libraries.html">Using CodeIgniter Libraries</a></li>
<li class="toctree-l2"><a class="reference internal" href="creating_libraries.html">Creating Libraries</a></li>
<li class="toctree-l2"><a class="reference internal" href="drivers.html">Using CodeIgniter Drivers</a></li>
<li class="toctree-l2"><a class="reference internal" href="creating_drivers.html">Creating Drivers</a></li>
<li class="toctree-l2"><a class="reference internal" href="core_classes.html">Creating Core System Classes</a></li>
<li class="toctree-l2"><a class="reference internal" href="ancillary_classes.html">Creating Ancillary Classes</a></li>
<li class="toctree-l2"><a class="reference internal" href="hooks.html">Hooks - Extending the Framework Core</a></li>
<li class="toctree-l2"><a class="reference internal" href="autoloader.html">Auto-loading Resources</a></li>
<li class="toctree-l2"><a class="reference internal" href="common_functions.html">Common Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="compatibility_functions.html">Compatibility Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="routing.html">URI Routing</a></li>
<li class="toctree-l2"><a class="reference internal" href="errors.html">Error Handling</a></li>
<li class="toctree-l2"><a class="reference internal" href="caching.html">Caching</a></li>
<li class="toctree-l2"><a class="reference internal" href="profiling.html">Profiling Your Application</a></li>
<li class="toctree-l2"><a class="reference internal" href="cli.html">Running via the CLI</a></li>
<li class="toctree-l2"><a class="reference internal" href="managing_apps.html">Managing your Applications</a></li>
<li class="toctree-l2"><a class="reference internal" href="environments.html">Handling Multiple Environments</a></li>
<li class="toctree-l2"><a class="reference internal" href="alternative_php.html">Alternate PHP Syntax for View Files</a></li>
<li class="toctree-l2"><a class="reference internal" href="security.html">Security</a></li>
<li class="toctree-l2 current"><a class="current reference internal" href="#">PHP Style Guide</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../libraries/index.html">Libraries</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../libraries/benchmark.html">Benchmarking Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/caching.html">Caching Driver</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/calendar.html">Calendaring Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/cart.html">Shopping Cart Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/config.html">Config Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/email.html">Email Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/encrypt.html">Encrypt Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/encryption.html">Encryption Library</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/file_uploading.html">File Uploading Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/form_validation.html">Form Validation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/ftp.html">FTP Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/image_lib.html">Image Manipulation Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/input.html">Input Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/javascript.html">Javascript Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/language.html">Language Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/loader.html">Loader Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/migration.html">Migrations Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/output.html">Output Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/pagination.html">Pagination Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/parser.html">Template Parser Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/security.html">Security Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/sessions.html">Session Library</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/table.html">HTML Table Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/trackback.html">Trackback Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/typography.html">Typography Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/unit_testing.html">Unit Testing Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/uri.html">URI Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/user_agent.html">User Agent Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/xmlrpc.html">XML-RPC and XML-RPC Server Classes</a></li>
<li class="toctree-l2"><a class="reference internal" href="../libraries/zip.html">Zip Encoding Class</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../database/index.html">Database Reference</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../database/examples.html">Quick Start: Usage Examples</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/configuration.html">Database Configuration</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/connecting.html">Connecting to a Database</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/queries.html">Running Queries</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/results.html">Generating Query Results</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/helpers.html">Query Helper Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/query_builder.html">Query Builder Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/transactions.html">Transactions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/metadata.html">Getting MetaData</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/call_function.html">Custom Function Calls</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/caching.html">Query Caching</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/forge.html">Database Manipulation with Database Forge</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/utilities.html">Database Utilities Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/db_driver_reference.html">Database Driver Reference</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../helpers/array_helper.html">Array Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/captcha_helper.html">CAPTCHA Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/cookie_helper.html">Cookie Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/date_helper.html">Date Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/directory_helper.html">Directory Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/download_helper.html">Download Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/email_helper.html">Email Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/file_helper.html">File Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/form_helper.html">Form Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/html_helper.html">HTML Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/inflector_helper.html">Inflector Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/language_helper.html">Language Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/number_helper.html">Number Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/path_helper.html">Path Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/security_helper.html">Security Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/smiley_helper.html">Smiley Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/string_helper.html">String Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/text_helper.html">Text Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/typography_helper.html">Typography Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/url_helper.html">URL Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/xml_helper.html">XML Helper</a></li>
</ul>
</li>
</ul>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
<nav class="wy-nav-top" role="navigation" aria-label="top navigation">
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="../index.html">CodeIgniter</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<div role="navigation" aria-label="breadcrumbs navigation">
<ul class="wy-breadcrumbs">
<li><a href="../index.html">Docs</a> »</li>
<li><a href="index.html">General Topics</a> »</li>
<li>PHP Style Guide</li>
<li class="wy-breadcrumbs-aside">
</li>
<div style="float:right;margin-left:5px;" id="closeMe">
<img title="Classic Layout" alt="classic layout" src="data:image/gif;base64,R0lGODlhFAAUAJEAAAAAADMzM////wAAACH5BAUUAAIALAAAAAAUABQAAAImlI+py+0PU5gRBRDM3DxbWoXis42X13USOLauUIqnlsaH/eY6UwAAOw==" />
</div>
</ul>
<hr/>
</div>
<div role="main" class="document">
<div class="section" id="php-style-guide">
<h1><a class="toc-backref" href="#id1">PHP Style Guide</a><a class="headerlink" href="#php-style-guide" title="Permalink to this headline">¶</a></h1>
<p>The following page describes the coding styles adhered to when
contributing to the development of CodeIgniter. There is no requirement
to use these styles in your own CodeIgniter application, though they
are recommended.</p>
<div class="contents topic" id="table-of-contents">
<p class="topic-title first">Table of Contents</p>
<ul class="simple">
<li><a class="reference internal" href="#php-style-guide" id="id1">PHP Style Guide</a><ul>
<li><a class="reference internal" href="#file-format" id="id2">File Format</a><ul>
<li><a class="reference internal" href="#textmate" id="id3">TextMate</a></li>
<li><a class="reference internal" href="#bbedit" id="id4">BBEdit</a></li>
</ul>
</li>
<li><a class="reference internal" href="#php-closing-tag" id="id5">PHP Closing Tag</a></li>
<li><a class="reference internal" href="#file-naming" id="id6">File Naming</a></li>
<li><a class="reference internal" href="#class-and-method-naming" id="id7">Class and Method Naming</a></li>
<li><a class="reference internal" href="#variable-names" id="id8">Variable Names</a></li>
<li><a class="reference internal" href="#commenting" id="id9">Commenting</a></li>
<li><a class="reference internal" href="#constants" id="id10">Constants</a></li>
<li><a class="reference internal" href="#true-false-and-null" id="id11">TRUE, FALSE, and NULL</a></li>
<li><a class="reference internal" href="#logical-operators" id="id12">Logical Operators</a></li>
<li><a class="reference internal" href="#comparing-return-values-and-typecasting" id="id13">Comparing Return Values and Typecasting</a></li>
<li><a class="reference internal" href="#debugging-code" id="id14">Debugging Code</a></li>
<li><a class="reference internal" href="#whitespace-in-files" id="id15">Whitespace in Files</a></li>
<li><a class="reference internal" href="#compatibility" id="id16">Compatibility</a></li>
<li><a class="reference internal" href="#one-file-per-class" id="id17">One File per Class</a></li>
<li><a class="reference internal" href="#whitespace" id="id18">Whitespace</a></li>
<li><a class="reference internal" href="#line-breaks" id="id19">Line Breaks</a></li>
<li><a class="reference internal" href="#code-indenting" id="id20">Code Indenting</a></li>
<li><a class="reference internal" href="#bracket-and-parenthetic-spacing" id="id21">Bracket and Parenthetic Spacing</a></li>
<li><a class="reference internal" href="#localized-text" id="id22">Localized Text</a></li>
<li><a class="reference internal" href="#private-methods-and-variables" id="id23">Private Methods and Variables</a></li>
<li><a class="reference internal" href="#php-errors" id="id24">PHP Errors</a></li>
<li><a class="reference internal" href="#short-open-tags" id="id25">Short Open Tags</a></li>
<li><a class="reference internal" href="#one-statement-per-line" id="id26">One Statement Per Line</a></li>
<li><a class="reference internal" href="#strings" id="id27">Strings</a></li>
<li><a class="reference internal" href="#sql-queries" id="id28">SQL Queries</a></li>
<li><a class="reference internal" href="#default-function-arguments" id="id29">Default Function Arguments</a></li>
</ul>
</li>
</ul>
</div>
<div class="section" id="file-format">
<h2><a class="toc-backref" href="#id2">File Format</a><a class="headerlink" href="#file-format" title="Permalink to this headline">¶</a></h2>
<p>Files should be saved with Unicode (UTF-8) encoding. The BOM should
<em>not</em> be used. Unlike UTF-16 and UTF-32, there’s no byte order to
indicate in a UTF-8 encoded file, and the BOM can have a negative side
effect in PHP of sending output, preventing the application from being
able to set its own headers. Unix line endings should be used (LF).</p>
<p>Here is how to apply these settings in some of the more common text
editors. Instructions for your text editor may vary; check your text
editor’s documentation.</p>
<div class="section" id="textmate">
<h3><a class="toc-backref" href="#id3">TextMate</a><a class="headerlink" href="#textmate" title="Permalink to this headline">¶</a></h3>
<ol class="arabic simple">
<li>Open the Application Preferences</li>
<li>Click Advanced, and then the “Saving” tab</li>
<li>In “File Encoding”, select “UTF-8 (recommended)”</li>
<li>In “Line Endings”, select “LF (recommended)”</li>
<li><em>Optional:</em> Check “Use for existing files as well” if you wish to
modify the line endings of files you open to your new preference.</li>
</ol>
</div>
<div class="section" id="bbedit">
<h3><a class="toc-backref" href="#id4">BBEdit</a><a class="headerlink" href="#bbedit" title="Permalink to this headline">¶</a></h3>
<ol class="arabic simple">
<li>Open the Application Preferences</li>
<li>Select “Text Encodings” on the left.</li>
<li>In “Default text encoding for new documents”, select “Unicode (UTF-8,
no BOM)”</li>
<li><em>Optional:</em> In “If file’s encoding can’t be guessed, use”, select
“Unicode (UTF-8, no BOM)”</li>
<li>Select “Text Files” on the left.</li>
<li>In “Default line breaks”, select “Mac OS X and Unix (LF)”</li>
</ol>
</div>
</div>
<div class="section" id="php-closing-tag">
<h2><a class="toc-backref" href="#id5">PHP Closing Tag</a><a class="headerlink" href="#php-closing-tag" title="Permalink to this headline">¶</a></h2>
<p>The PHP closing tag on a PHP document <strong>?></strong> is optional to the PHP
parser. However, if used, any whitespace following the closing tag,
whether introduced by the developer, user, or an FTP application, can
cause unwanted output, PHP errors, or if the latter are suppressed,
blank pages. For this reason, all PHP files MUST OMIT the PHP closing
tag and end with a single empty line instead.</p>
</div>
<div class="section" id="file-naming">
<h2><a class="toc-backref" href="#id6">File Naming</a><a class="headerlink" href="#file-naming" title="Permalink to this headline">¶</a></h2>
<p>Class files must be named in a Ucfirst-like manner, while any other file name
(configurations, views, generic scripts, etc.) should be in all lowercase.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">somelibrary</span><span class="o">.</span><span class="nx">php</span>
<span class="nx">someLibrary</span><span class="o">.</span><span class="nx">php</span>
<span class="nx">SOMELIBRARY</span><span class="o">.</span><span class="nx">php</span>
<span class="nx">Some_Library</span><span class="o">.</span><span class="nx">php</span>
<span class="nx">Application_config</span><span class="o">.</span><span class="nx">php</span>
<span class="nx">Application_Config</span><span class="o">.</span><span class="nx">php</span>
<span class="nx">applicationConfig</span><span class="o">.</span><span class="nx">php</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">Somelibrary</span><span class="o">.</span><span class="nx">php</span>
<span class="nx">Some_library</span><span class="o">.</span><span class="nx">php</span>
<span class="nx">applicationconfig</span><span class="o">.</span><span class="nx">php</span>
<span class="nx">application_config</span><span class="o">.</span><span class="nx">php</span>
</pre></div>
</div>
<p>Furthermore, class file names should match the name of the class itself.
For example, if you have a class named <cite>Myclass</cite>, then its filename must
be <strong>Myclass.php</strong>.</p>
</div>
<div class="section" id="class-and-method-naming">
<h2><a class="toc-backref" href="#id7">Class and Method Naming</a><a class="headerlink" href="#class-and-method-naming" title="Permalink to this headline">¶</a></h2>
<p>Class names should always start with an uppercase letter. Multiple words
should be separated with an underscore, and not CamelCased.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">class</span> <span class="nc">superclass</span>
<span class="k">class</span> <span class="nc">SuperClass</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">class</span> <span class="nc">Super_class</span>
</pre></div>
</div>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">class</span> <span class="nc">Super_class</span> <span class="p">{</span>
<span class="k">public</span> <span class="k">function</span> <span class="nf">__construct</span><span class="p">()</span>
<span class="p">{</span>
<span class="p">}</span>
<span class="p">}</span>
</pre></div>
</div>
<p>Class methods should be entirely lowercased and named to clearly
indicate their function, preferably including a verb. Try to avoid
overly long and verbose names. Multiple words should be separated
with an underscore.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">function</span> <span class="nf">fileproperties</span><span class="p">()</span> <span class="c1">// not descriptive and needs underscore separator</span>
<span class="k">function</span> <span class="nf">fileProperties</span><span class="p">()</span> <span class="c1">// not descriptive and uses CamelCase</span>
<span class="k">function</span> <span class="nf">getfileproperties</span><span class="p">()</span> <span class="c1">// Better! But still missing underscore separator</span>
<span class="k">function</span> <span class="nf">getFileProperties</span><span class="p">()</span> <span class="c1">// uses CamelCase</span>
<span class="k">function</span> <span class="nf">get_the_file_properties_from_the_file</span><span class="p">()</span> <span class="c1">// wordy</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">function</span> <span class="nf">get_file_properties</span><span class="p">()</span> <span class="c1">// descriptive, underscore separator, and all lowercase letters</span>
</pre></div>
</div>
</div>
<div class="section" id="variable-names">
<h2><a class="toc-backref" href="#id8">Variable Names</a><a class="headerlink" href="#variable-names" title="Permalink to this headline">¶</a></h2>
<p>The guidelines for variable naming are very similar to those used for
class methods. Variables should contain only lowercase letters,
use underscore separators, and be reasonably named to indicate their
purpose and contents. Very short, non-word variables should only be used
as iterators in for() loops.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$j</span> <span class="o">=</span> <span class="s1">'foo'</span><span class="p">;</span> <span class="c1">// single letter variables should only be used in for() loops</span>
<span class="nv">$Str</span> <span class="c1">// contains uppercase letters</span>
<span class="nv">$bufferedText</span> <span class="c1">// uses CamelCasing, and could be shortened without losing semantic meaning</span>
<span class="nv">$groupid</span> <span class="c1">// multiple words, needs underscore separator</span>
<span class="nv">$name_of_last_city_used</span> <span class="c1">// too long</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">for</span> <span class="p">(</span><span class="nv">$j</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nv">$j</span> <span class="o"><</span> <span class="mi">10</span><span class="p">;</span> <span class="nv">$j</span><span class="o">++</span><span class="p">)</span>
<span class="nv">$str</span>
<span class="nv">$buffer</span>
<span class="nv">$group_id</span>
<span class="nv">$last_city</span>
</pre></div>
</div>
</div>
<div class="section" id="commenting">
<h2><a class="toc-backref" href="#id9">Commenting</a><a class="headerlink" href="#commenting" title="Permalink to this headline">¶</a></h2>
<p>In general, code should be commented prolifically. It not only helps
describe the flow and intent of the code for less experienced
programmers, but can prove invaluable when returning to your own code
months down the line. There is not a required format for comments, but
the following are recommended.</p>
<p><a class="reference external" href="http://manual.phpdoc.org/HTMLSmartyConverter/HandS/phpDocumentor/tutorial_phpDocumentor.howto.pkg.html#basics.docblock">DocBlock</a>
style comments preceding class, method, and property declarations so they can be
picked up by IDEs:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="sd">/**</span>
<span class="sd"> * Super Class</span>
<span class="sd"> *</span>
<span class="sd"> * @package Package Name</span>
<span class="sd"> * @subpackage Subpackage</span>
<span class="sd"> * @category Category</span>
<span class="sd"> * @author Author Name</span>
<span class="sd"> * @link http://example.com</span>
<span class="sd"> */</span>
<span class="k">class</span> <span class="nc">Super_class</span> <span class="p">{</span>
</pre></div>
</div>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="sd">/**</span>
<span class="sd"> * Encodes string for use in XML</span>
<span class="sd"> *</span>
<span class="sd"> * @param string $str Input string</span>
<span class="sd"> * @return string</span>
<span class="sd"> */</span>
<span class="k">function</span> <span class="nf">xml_encode</span><span class="p">(</span><span class="nv">$str</span><span class="p">)</span>
</pre></div>
</div>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="sd">/**</span>
<span class="sd"> * Data for class manipulation</span>
<span class="sd"> *</span>
<span class="sd"> * @var array</span>
<span class="sd"> */</span>
<span class="k">public</span> <span class="nv">$data</span> <span class="o">=</span> <span class="k">array</span><span class="p">();</span>
</pre></div>
</div>
<p>Use single line comments within code, leaving a blank line between large
comment blocks and code.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="c1">// break up the string by newlines</span>
<span class="nv">$parts</span> <span class="o">=</span> <span class="nb">explode</span><span class="p">(</span><span class="s2">"</span><span class="se">\n</span><span class="s2">"</span><span class="p">,</span> <span class="nv">$str</span><span class="p">);</span>
<span class="c1">// A longer comment that needs to give greater detail on what is</span>
<span class="c1">// occurring and why can use multiple single-line comments. Try to</span>
<span class="c1">// keep the width reasonable, around 70 characters is the easiest to</span>
<span class="c1">// read. Don't hesitate to link to permanent external resources</span>
<span class="c1">// that may provide greater detail:</span>
<span class="c1">//</span>
<span class="c1">// http://example.com/information_about_something/in_particular/</span>
<span class="nv">$parts</span> <span class="o">=</span> <span class="nv">$this</span><span class="o">-></span><span class="na">foo</span><span class="p">(</span><span class="nv">$parts</span><span class="p">);</span>
</pre></div>
</div>
</div>
<div class="section" id="constants">
<h2><a class="toc-backref" href="#id10">Constants</a><a class="headerlink" href="#constants" title="Permalink to this headline">¶</a></h2>
<p>Constants follow the same guidelines as do variables, except constants
should always be fully uppercase. <em>Always use CodeIgniter constants when
appropriate, i.e. SLASH, LD, RD, PATH_CACHE, etc.</em></p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">myConstant</span> <span class="c1">// missing underscore separator and not fully uppercase</span>
<span class="nx">N</span> <span class="c1">// no single-letter constants</span>
<span class="nx">S_C_VER</span> <span class="c1">// not descriptive</span>
<span class="nv">$str</span> <span class="o">=</span> <span class="nb">str_replace</span><span class="p">(</span><span class="s1">'{foo}'</span><span class="p">,</span> <span class="s1">'bar'</span><span class="p">,</span> <span class="nv">$str</span><span class="p">);</span> <span class="c1">// should use LD and RD constants</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">MY_CONSTANT</span>
<span class="nx">NEWLINE</span>
<span class="nx">SUPER_CLASS_VERSION</span>
<span class="nv">$str</span> <span class="o">=</span> <span class="nb">str_replace</span><span class="p">(</span><span class="nx">LD</span><span class="o">.</span><span class="s1">'foo'</span><span class="o">.</span><span class="nx">RD</span><span class="p">,</span> <span class="s1">'bar'</span><span class="p">,</span> <span class="nv">$str</span><span class="p">);</span>
</pre></div>
</div>
</div>
<div class="section" id="true-false-and-null">
<h2><a class="toc-backref" href="#id11">TRUE, FALSE, and NULL</a><a class="headerlink" href="#true-false-and-null" title="Permalink to this headline">¶</a></h2>
<p><strong>TRUE</strong>, <strong>FALSE</strong>, and <strong>NULL</strong> keywords should always be fully
uppercase.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nv">$foo</span> <span class="o">==</span> <span class="k">true</span><span class="p">)</span>
<span class="nv">$bar</span> <span class="o">=</span> <span class="k">false</span><span class="p">;</span>
<span class="k">function</span> <span class="nf">foo</span><span class="p">(</span><span class="nv">$bar</span> <span class="o">=</span> <span class="k">null</span><span class="p">)</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nv">$foo</span> <span class="o">==</span> <span class="k">TRUE</span><span class="p">)</span>
<span class="nv">$bar</span> <span class="o">=</span> <span class="k">FALSE</span><span class="p">;</span>
<span class="k">function</span> <span class="nf">foo</span><span class="p">(</span><span class="nv">$bar</span> <span class="o">=</span> <span class="k">NULL</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="logical-operators">
<h2><a class="toc-backref" href="#id12">Logical Operators</a><a class="headerlink" href="#logical-operators" title="Permalink to this headline">¶</a></h2>
<p>Use of the <code class="docutils literal"><span class="pre">||</span></code> “or” comparison operator is discouraged, as its clarity
on some output devices is low (looking like the number 11, for instance).
<code class="docutils literal"><span class="pre">&&</span></code> is preferred over <code class="docutils literal"><span class="pre">AND</span></code> but either are acceptable, and a space should
always precede and follow <code class="docutils literal"><span class="pre">!</span></code>.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nv">$foo</span> <span class="o">||</span> <span class="nv">$bar</span><span class="p">)</span>
<span class="k">if</span> <span class="p">(</span><span class="nv">$foo</span> <span class="k">AND</span> <span class="nv">$bar</span><span class="p">)</span> <span class="c1">// okay but not recommended for common syntax highlighting applications</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nv">$foo</span><span class="p">)</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span> <span class="nb">is_array</span><span class="p">(</span><span class="nv">$foo</span><span class="p">))</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nv">$foo</span> <span class="k">OR</span> <span class="nv">$bar</span><span class="p">)</span>
<span class="k">if</span> <span class="p">(</span><span class="nv">$foo</span> <span class="o">&&</span> <span class="nv">$bar</span><span class="p">)</span> <span class="c1">// recommended</span>
<span class="k">if</span> <span class="p">(</span> <span class="o">!</span> <span class="nv">$foo</span><span class="p">)</span>
<span class="k">if</span> <span class="p">(</span> <span class="o">!</span> <span class="nb">is_array</span><span class="p">(</span><span class="nv">$foo</span><span class="p">))</span>
</pre></div>
</div>
</div>
<div class="section" id="comparing-return-values-and-typecasting">
<h2><a class="toc-backref" href="#id13">Comparing Return Values and Typecasting</a><a class="headerlink" href="#comparing-return-values-and-typecasting" title="Permalink to this headline">¶</a></h2>
<p>Some PHP functions return FALSE on failure, but may also have a valid
return value of “” or 0, which would evaluate to FALSE in loose
comparisons. Be explicit by comparing the variable type when using these
return values in conditionals to ensure the return value is indeed what
you expect, and not a value that has an equivalent loose-type
evaluation.</p>
<p>Use the same stringency in returning and checking your own variables.
Use <strong>===</strong> and <strong>!==</strong> as necessary.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="c1">// If 'foo' is at the beginning of the string, strpos will return a 0,</span>
<span class="c1">// resulting in this conditional evaluating as TRUE</span>
<span class="k">if</span> <span class="p">(</span><span class="nb">strpos</span><span class="p">(</span><span class="nv">$str</span><span class="p">,</span> <span class="s1">'foo'</span><span class="p">)</span> <span class="o">==</span> <span class="k">FALSE</span><span class="p">)</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nb">strpos</span><span class="p">(</span><span class="nv">$str</span><span class="p">,</span> <span class="s1">'foo'</span><span class="p">)</span> <span class="o">===</span> <span class="k">FALSE</span><span class="p">)</span>
</pre></div>
</div>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">function</span> <span class="nf">build_string</span><span class="p">(</span><span class="nv">$str</span> <span class="o">=</span> <span class="s2">""</span><span class="p">)</span>
<span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nv">$str</span> <span class="o">==</span> <span class="s2">""</span><span class="p">)</span> <span class="c1">// uh-oh! What if FALSE or the integer 0 is passed as an argument?</span>
<span class="p">{</span>
<span class="p">}</span>
<span class="p">}</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">function</span> <span class="nf">build_string</span><span class="p">(</span><span class="nv">$str</span> <span class="o">=</span> <span class="s2">""</span><span class="p">)</span>
<span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nv">$str</span> <span class="o">===</span> <span class="s2">""</span><span class="p">)</span>
<span class="p">{</span>
<span class="p">}</span>
<span class="p">}</span>
</pre></div>
</div>
<p>See also information regarding <a class="reference external" href="http://php.net/manual/en/language.types.type-juggling.php#language.types.typecasting">typecasting</a>,
which can be quite useful. Typecasting has a slightly different effect
which may be desirable. When casting a variable as a string, for
instance, NULL and boolean FALSE variables become empty strings, 0 (and
other numbers) become strings of digits, and boolean TRUE becomes “1”:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$str</span> <span class="o">=</span> <span class="p">(</span><span class="nx">string</span><span class="p">)</span> <span class="nv">$str</span><span class="p">;</span> <span class="c1">// cast $str as a string</span>
</pre></div>
</div>
</div>
<div class="section" id="debugging-code">
<h2><a class="toc-backref" href="#id14">Debugging Code</a><a class="headerlink" href="#debugging-code" title="Permalink to this headline">¶</a></h2>
<p>Do not leave debugging code in your submissions, even when commented out.
Things such as <code class="docutils literal"><span class="pre">var_dump()</span></code>, <code class="docutils literal"><span class="pre">print_r()</span></code>, <code class="docutils literal"><span class="pre">die()</span></code>/<code class="docutils literal"><span class="pre">exit()</span></code> should not be included
in your code unless it serves a specific purpose other than debugging.</p>
</div>
<div class="section" id="whitespace-in-files">
<h2><a class="toc-backref" href="#id15">Whitespace in Files</a><a class="headerlink" href="#whitespace-in-files" title="Permalink to this headline">¶</a></h2>
<p>No whitespace can precede the opening PHP tag or follow the closing PHP
tag. Output is buffered, so whitespace in your files can cause output to
begin before CodeIgniter outputs its content, leading to errors and an
inability for CodeIgniter to send proper headers.</p>
</div>
<div class="section" id="compatibility">
<h2><a class="toc-backref" href="#id16">Compatibility</a><a class="headerlink" href="#compatibility" title="Permalink to this headline">¶</a></h2>
<p>CodeIgniter recommends PHP 5.6 or newer to be used, but it should be
compatible with PHP 5.3.7. Your code must either be compatible with this
requirement, provide a suitable fallback, or be an optional feature that
dies quietly without affecting a user’s application.</p>
<p>Additionally, do not use PHP functions that require non-default libraries
to be installed unless your code contains an alternative method when the
function is not available.</p>
</div>
<div class="section" id="one-file-per-class">
<h2><a class="toc-backref" href="#id17">One File per Class</a><a class="headerlink" href="#one-file-per-class" title="Permalink to this headline">¶</a></h2>
<p>Use separate files for each class, unless the classes are <em>closely related</em>.
An example of a CodeIgniter file that contains multiple classes is the
Xmlrpc library file.</p>
</div>
<div class="section" id="whitespace">
<h2><a class="toc-backref" href="#id18">Whitespace</a><a class="headerlink" href="#whitespace" title="Permalink to this headline">¶</a></h2>
<p>Use tabs for whitespace in your code, not spaces. This may seem like a
small thing, but using tabs instead of whitespace allows the developer
looking at your code to have indentation at levels that they prefer and
customize in whatever application they use. And as a side benefit, it
results in (slightly) more compact files, storing one tab character
versus, say, four space characters.</p>
</div>
<div class="section" id="line-breaks">
<h2><a class="toc-backref" href="#id19">Line Breaks</a><a class="headerlink" href="#line-breaks" title="Permalink to this headline">¶</a></h2>
<p>Files must be saved with Unix line breaks. This is more of an issue for
developers who work in Windows, but in any case ensure that your text
editor is setup to save files with Unix line breaks.</p>
</div>
<div class="section" id="code-indenting">
<h2><a class="toc-backref" href="#id20">Code Indenting</a><a class="headerlink" href="#code-indenting" title="Permalink to this headline">¶</a></h2>
<p>Use Allman style indenting. With the exception of Class declarations,
braces are always placed on a line by themselves, and indented at the
same level as the control statement that “owns” them.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">function</span> <span class="nf">foo</span><span class="p">(</span><span class="nv">$bar</span><span class="p">)</span> <span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="k">foreach</span> <span class="p">(</span><span class="nv">$arr</span> <span class="k">as</span> <span class="nv">$key</span> <span class="o">=></span> <span class="nv">$val</span><span class="p">)</span> <span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nv">$foo</span> <span class="o">==</span> <span class="nv">$bar</span><span class="p">)</span> <span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="k">for</span> <span class="p">(</span><span class="nv">$i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nv">$i</span> <span class="o"><</span> <span class="mi">10</span><span class="p">;</span> <span class="nv">$i</span><span class="o">++</span><span class="p">)</span>
<span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="nv">$j</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nv">$j</span> <span class="o"><</span> <span class="mi">10</span><span class="p">;</span> <span class="nv">$j</span><span class="o">++</span><span class="p">)</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="k">try</span> <span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="k">catch</span><span class="p">()</span> <span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">function</span> <span class="nf">foo</span><span class="p">(</span><span class="nv">$bar</span><span class="p">)</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="k">foreach</span> <span class="p">(</span><span class="nv">$arr</span> <span class="k">as</span> <span class="nv">$key</span> <span class="o">=></span> <span class="nv">$val</span><span class="p">)</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nv">$foo</span> <span class="o">==</span> <span class="nv">$bar</span><span class="p">)</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="k">else</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="k">for</span> <span class="p">(</span><span class="nv">$i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nv">$i</span> <span class="o"><</span> <span class="mi">10</span><span class="p">;</span> <span class="nv">$i</span><span class="o">++</span><span class="p">)</span>
<span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="nv">$j</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nv">$j</span> <span class="o"><</span> <span class="mi">10</span><span class="p">;</span> <span class="nv">$j</span><span class="o">++</span><span class="p">)</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="k">try</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
<span class="k">catch</span><span class="p">()</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
</pre></div>
</div>
</div>
<div class="section" id="bracket-and-parenthetic-spacing">
<h2><a class="toc-backref" href="#id21">Bracket and Parenthetic Spacing</a><a class="headerlink" href="#bracket-and-parenthetic-spacing" title="Permalink to this headline">¶</a></h2>
<p>In general, parenthesis and brackets should not use any additional
spaces. The exception is that a space should always follow PHP control
structures that accept arguments with parenthesis (declare, do-while,
elseif, for, foreach, if, switch, while), to help distinguish them from
functions and increase readability.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$arr</span><span class="p">[</span> <span class="nv">$foo</span> <span class="p">]</span> <span class="o">=</span> <span class="s1">'foo'</span><span class="p">;</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$arr</span><span class="p">[</span><span class="nv">$foo</span><span class="p">]</span> <span class="o">=</span> <span class="s1">'foo'</span><span class="p">;</span> <span class="c1">// no spaces around array keys</span>
</pre></div>
</div>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">function</span> <span class="nf">foo</span> <span class="p">(</span> <span class="nv">$bar</span> <span class="p">)</span>
<span class="p">{</span>
<span class="p">}</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">function</span> <span class="nf">foo</span><span class="p">(</span><span class="nv">$bar</span><span class="p">)</span> <span class="c1">// no spaces around parenthesis in function declarations</span>
<span class="p">{</span>
<span class="p">}</span>
</pre></div>
</div>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">foreach</span><span class="p">(</span> <span class="nv">$query</span><span class="o">-></span><span class="na">result</span><span class="p">()</span> <span class="k">as</span> <span class="nv">$row</span> <span class="p">)</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">foreach</span> <span class="p">(</span><span class="nv">$query</span><span class="o">-></span><span class="na">result</span><span class="p">()</span> <span class="k">as</span> <span class="nv">$row</span><span class="p">)</span> <span class="c1">// single space following PHP control structures, but not in interior parenthesis</span>
</pre></div>
</div>
</div>
<div class="section" id="localized-text">
<h2><a class="toc-backref" href="#id22">Localized Text</a><a class="headerlink" href="#localized-text" title="Permalink to this headline">¶</a></h2>
<p>CodeIgniter libraries should take advantage of corresponding language files
whenever possible.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">return</span> <span class="s2">"Invalid Selection"</span><span class="p">;</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">return</span> <span class="nv">$this</span><span class="o">-></span><span class="na">lang</span><span class="o">-></span><span class="na">line</span><span class="p">(</span><span class="s1">'invalid_selection'</span><span class="p">);</span>
</pre></div>
</div>
</div>
<div class="section" id="private-methods-and-variables">
<h2><a class="toc-backref" href="#id23">Private Methods and Variables</a><a class="headerlink" href="#private-methods-and-variables" title="Permalink to this headline">¶</a></h2>
<p>Methods and variables that are only accessed internally,
such as utility and helper functions that your public methods use for
code abstraction, should be prefixed with an underscore.</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">public</span> <span class="k">function</span> <span class="nf">convert_text</span><span class="p">()</span>
<span class="k">private</span> <span class="k">function</span> <span class="nf">_convert_text</span><span class="p">()</span>
</pre></div>
</div>
</div>
<div class="section" id="php-errors">
<h2><a class="toc-backref" href="#id24">PHP Errors</a><a class="headerlink" href="#php-errors" title="Permalink to this headline">¶</a></h2>
<p>Code must run error free and not rely on warnings and notices to be
hidden to meet this requirement. For instance, never access a variable
that you did not set yourself (such as <code class="docutils literal"><span class="pre">$_POST</span></code> array keys) without first
checking to see that it <code class="docutils literal"><span class="pre">isset()</span></code>.</p>
<p>Make sure that your dev environment has error reporting enabled
for ALL users, and that display_errors is enabled in the PHP
environment. You can check this setting with:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nb">ini_get</span><span class="p">(</span><span class="s1">'display_errors'</span><span class="p">)</span> <span class="o">==</span> <span class="mi">1</span><span class="p">)</span>
<span class="p">{</span>
<span class="k">exit</span> <span class="s2">"Enabled"</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
<p>On some servers where <em>display_errors</em> is disabled, and you do not have
the ability to change this in the php.ini, you can often enable it with:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nb">ini_set</span><span class="p">(</span><span class="s1">'display_errors'</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">Setting the <a class="reference external" href="http://php.net/manual/en/errorfunc.configuration.php#ini.display-errors">display_errors</a>
setting with <code class="docutils literal"><span class="pre">ini_set()</span></code> at runtime is not identical to having
it enabled in the PHP environment. Namely, it will not have any
effect if the script has fatal errors.</p>
</div>
</div>
<div class="section" id="short-open-tags">
<h2><a class="toc-backref" href="#id25">Short Open Tags</a><a class="headerlink" href="#short-open-tags" title="Permalink to this headline">¶</a></h2>
<p>Always use full PHP opening tags, in case a server does not have
<em>short_open_tag</em> enabled.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="o"><?</span> <span class="k">echo</span> <span class="nv">$foo</span><span class="p">;</span> <span class="cp">?></span>
<span class="cp"><?</span><span class="o">=</span><span class="nv">$foo</span><span class="cp">?></span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="o"><?</span><span class="nx">php</span> <span class="k">echo</span> <span class="nv">$foo</span><span class="p">;</span> <span class="cp">?></span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">PHP 5.4 will always have the <strong><?=</strong> tag available.</p>
</div>
</div>
<div class="section" id="one-statement-per-line">
<h2><a class="toc-backref" href="#id26">One Statement Per Line</a><a class="headerlink" href="#one-statement-per-line" title="Permalink to this headline">¶</a></h2>
<p>Never combine statements on one line.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$foo</span> <span class="o">=</span> <span class="s1">'this'</span><span class="p">;</span> <span class="nv">$bar</span> <span class="o">=</span> <span class="s1">'that'</span><span class="p">;</span> <span class="nv">$bat</span> <span class="o">=</span> <span class="nb">str_replace</span><span class="p">(</span><span class="nv">$foo</span><span class="p">,</span> <span class="nv">$bar</span><span class="p">,</span> <span class="nv">$bag</span><span class="p">);</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$foo</span> <span class="o">=</span> <span class="s1">'this'</span><span class="p">;</span>
<span class="nv">$bar</span> <span class="o">=</span> <span class="s1">'that'</span><span class="p">;</span>
<span class="nv">$bat</span> <span class="o">=</span> <span class="nb">str_replace</span><span class="p">(</span><span class="nv">$foo</span><span class="p">,</span> <span class="nv">$bar</span><span class="p">,</span> <span class="nv">$bag</span><span class="p">);</span>
</pre></div>
</div>
</div>
<div class="section" id="strings">
<h2><a class="toc-backref" href="#id27">Strings</a><a class="headerlink" href="#strings" title="Permalink to this headline">¶</a></h2>
<p>Always use single quoted strings unless you need variables parsed, and
in cases where you do need variables parsed, use braces to prevent
greedy token parsing. You may also use double-quoted strings if the
string contains single quotes, so you do not have to use escape
characters.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="s2">"My String"</span> <span class="c1">// no variable parsing, so no use for double quotes</span>
<span class="s2">"My string </span><span class="si">$foo</span><span class="s2">"</span> <span class="c1">// needs braces</span>
<span class="s1">'SELECT foo FROM bar WHERE baz = \'bag\''</span> <span class="c1">// ugly</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="s1">'My String'</span>
<span class="s2">"My string </span><span class="si">{</span><span class="nv">$foo</span><span class="si">}</span><span class="s2">"</span>
<span class="s2">"SELECT foo FROM bar WHERE baz = 'bag'"</span>
</pre></div>
</div>
</div>
<div class="section" id="sql-queries">
<h2><a class="toc-backref" href="#id28">SQL Queries</a><a class="headerlink" href="#sql-queries" title="Permalink to this headline">¶</a></h2>
<p>SQL keywords are always capitalized: SELECT, INSERT, UPDATE, WHERE,
AS, JOIN, ON, IN, etc.</p>
<p>Break up long queries into multiple lines for legibility, preferably
breaking for each clause.</p>
<p><strong>INCORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="c1">// keywords are lowercase and query is too long for</span>
<span class="c1">// a single line (... indicates continuation of line)</span>
<span class="nv">$query</span> <span class="o">=</span> <span class="nv">$this</span><span class="o">-></span><span class="na">db</span><span class="o">-></span><span class="na">query</span><span class="p">(</span><span class="s2">"select foo, bar, baz, foofoo, foobar as raboof, foobaz from exp_pre_email_addresses</span>
<span class="s2">...where foo != 'oof' and baz != 'zab' order by foobaz limit 5, 100"</span><span class="p">);</span>
</pre></div>
</div>
<p><strong>CORRECT</strong>:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$query</span> <span class="o">=</span> <span class="nv">$this</span><span class="o">-></span><span class="na">db</span><span class="o">-></span><span class="na">query</span><span class="p">(</span><span class="s2">"SELECT foo, bar, baz, foofoo, foobar AS raboof, foobaz</span>
<span class="s2"> FROM exp_pre_email_addresses</span>
<span class="s2"> WHERE foo != 'oof'</span>
<span class="s2"> AND baz != 'zab'</span>
<span class="s2"> ORDER BY foobaz</span>
<span class="s2"> LIMIT 5, 100"</span><span class="p">);</span>
</pre></div>
</div>
</div>
<div class="section" id="default-function-arguments">
<h2><a class="toc-backref" href="#id29">Default Function Arguments</a><a class="headerlink" href="#default-function-arguments" title="Permalink to this headline">¶</a></h2>
<p>Whenever appropriate, provide function argument defaults, which helps
prevent PHP errors with mistaken calls and provides common fallback
values which can save a few lines of code. Example:</p>
<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">function</span> <span class="nf">foo</span><span class="p">(</span><span class="nv">$bar</span> <span class="o">=</span> <span class="s1">''</span><span class="p">,</span> <span class="nv">$baz</span> <span class="o">=</span> <span class="k">FALSE</span><span class="p">)</span>
</pre></div>
</div>
</div>
</div>
</div>
<footer>
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
<a href="../libraries/index.html" class="btn btn-neutral float-right" title="Libraries">Next <span class="fa fa-arrow-circle-right"></span></a>
<a href="security.html" class="btn btn-neutral" title="Security"><span class="fa fa-arrow-circle-left"></span> Previous</a>
</div>
<hr/>
<div role="contentinfo">
<p>
© Copyright 2014 - 2019, British Columbia Institute of Technology.
Last updated on Jan 16, 2019.
</p>
</div>
Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/snide/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT:'../',
VERSION:'3.1.10',
COLLAPSE_INDEX:false,
FILE_SUFFIX:'.html',
HAS_SOURCE: false
};
</script>
<script type="text/javascript" src="../_static/jquery.js"></script>
<script type="text/javascript" src="../_static/underscore.js"></script>
<script type="text/javascript" src="../_static/doctools.js"></script>
<script type="text/javascript" src="../_static/js/theme.js"></script>
<script type="text/javascript">
jQuery(function () {
SphinxRtdTheme.StickyNav.enable();
});
</script>
</body>
</html>
|
