diff options
Diffstat (limited to 'user_guide_src/source/libraries')
| -rw-r--r-- | user_guide_src/source/libraries/loader.rst | 71 | ||||
| -rw-r--r-- | user_guide_src/source/libraries/sessions.rst | 338 |
2 files changed, 326 insertions, 83 deletions
diff --git a/user_guide_src/source/libraries/loader.rst b/user_guide_src/source/libraries/loader.rst index aadf9740a..33c1bafec 100644 --- a/user_guide_src/source/libraries/loader.rst +++ b/user_guide_src/source/libraries/loader.rst @@ -4,6 +4,7 @@ Loader Class Loader, as the name suggests, is used to load elements. These elements can be libraries (classes) :doc:`View files <../general/views>`, +:doc:`Drivers <../general/drivers>`, :doc:`Helpers <../general/helpers>`, :doc:`Models <../general/models>`, or your own files. @@ -74,6 +75,70 @@ Assigning a Library to a different object name If the third (optional) parameter is blank, the library will usually be assigned to an object with the same name as the library. For example, if +the library is named Calendar, it will be assigned to a variable named +$this->calendar. + +If you prefer to set your own class names you can pass its value to the +third parameter:: + + $this->load->library('calendar', '', 'my_calendar'); + + // Calendar class is now accessed using: + + $this->my_calendar + +Please take note, when multiple libraries are supplied in an array for +the first parameter, this parameter is discarded. + +$this->load->driver('parent_name', $config, 'object name') +=========================================================== + +This function is used to load driver libraries. Where parent_name is the +name of the parent class you want to load. + +As an example, if you would like to use sessions with CodeIgniter, the first +step is to load the session driver within your controller:: + + $this->load->driver('session'); + +Once loaded, the library will be ready for use, using +$this->session->*some_function*(). + +Driver files must be stored in a subdirectory within the main +"libraries" folder, or within your personal application/libraries +folder. The subdirectory must match the parent class name. Read the +:doc:`Drivers <../general/drivers>` description for details. + +Additionally, multiple driver libraries can be loaded at the same time by +passing an array of drivers to the load function. + +:: + + $this->load->driver(array('session', 'cache')); + +Setting options +--------------- + +The second (optional) parameter allows you to optionally pass +configuration settings. You will typically pass these as an array:: + + $config = array ( + 'sess_driver' => 'cookie', + 'sess_encrypt_cookie' => true, + 'encryption_key' => 'mysecretkey' + ); + + $this->load->driver('session', $config); + +Config options can usually also be set via a config file. Each library +is explained in detail in its own page, so please read the information +regarding each one you would like to use. + +Assigning a Driver to a different object name +---------------------------------------------- + +If the third (optional) parameter is blank, the library will be assigned +to an object with the same name as the parent class. For example, if the library is named Session, it will be assigned to a variable named $this->session. @@ -86,8 +151,8 @@ third parameter:: $this->my_session -Please take note, when multiple libraries are supplied in an array for -the first parameter, this parameter is discarded. +.. note:: Driver libraries may also be loaded with the library() method, + but it is faster to use driver() $this->load->view('file_name', $data, true/false) ================================================== @@ -281,4 +346,4 @@ calling add_package_path(). // Again without the second parameter: $this->load->add_package_path(APPPATH.'my_app', TRUE); $this->load->view('my_app_index'); // Loads - $this->load->view('welcome_message'); // Loads
\ No newline at end of file + $this->load->view('welcome_message'); // Loads diff --git a/user_guide_src/source/libraries/sessions.rst b/user_guide_src/source/libraries/sessions.rst index 5400524a9..dd9e8cbb4 100644 --- a/user_guide_src/source/libraries/sessions.rst +++ b/user_guide_src/source/libraries/sessions.rst @@ -1,29 +1,19 @@ -############# -Session Class -############# +############## +Session Driver +############## The Session class permits you maintain a user's "state" and track their -activity while they browse your site. The Session class stores session -information for each user as serialized (and optionally encrypted) data -in a cookie. It can also store the session data in a database table for -added security, as this permits the session ID in the user's cookie to -be matched against the stored session ID. By default only the cookie is -saved. If you choose to use the database option you'll need to create -the session table as indicated below. - -.. note:: The Session class does **not** utilize native PHP sessions. It - generates its own session data, offering more flexibility for - developers. - -.. note:: Even if you are not using encrypted sessions, you must set - an :doc:`encryption key <./encryption>` in your config file which is used - to aid in preventing session data manipulation. +activity while they browse your site. CodeIgniter offers two default +session drivers: the classic `Cookie Driver`_, and the `Native Driver`_, +which supports usage of the native PHP Session mechanism. In addition, +you may create your own `Custom Drivers`_ to store session data however +you wish, while still taking advantage of the features of the Session class. Initializing a Session ====================== Sessions will typically run globally with each page load, so the session -class must either be :doc:`initialized <../general/libraries>` in your +class must either be :doc:`initialized <../general/drivers>` in your :doc:`controller <../general/controllers>` constructors, or it can be :doc:`auto-loaded <../general/autoloader>` by the system. For the most part the session class will run unattended in the background, so simply @@ -31,22 +21,25 @@ initializing the class will cause it to read, create, and update sessions. To initialize the Session class manually in your controller constructor, -use the $this->load->library function:: +use the $this->load->driver function:: - $this->load->library('session'); + $this->load->driver('session'); Once loaded, the Sessions library object will be available using: $this->session +.. note:: For backward compatibility, the Session class may stil be loaded + using the $this->load->library function, but converting your applications + to use $this->load->driver is strongly recommended. + How do Sessions work? ===================== When a page is loaded, the session class will check to see if valid -session data exists in the user's session cookie. If sessions data does -**not** exist (or if it has expired) a new session will be created and -saved in the cookie. If a session does exist, its information will be -updated and the cookie will be updated. With each update, the -session_id will be regenerated. +session data exists in the user's session. If sessions data does **not** +exist (or if it has expired) a new session will be created and saved. +If a session does exist, its information will be updated. With each update, +the session_id will be regenerated. It's important for you to understand that once initialized, the Session class runs automatically. There is nothing you need to do to cause the @@ -79,19 +72,12 @@ prototype:: 'last_activity' => timestamp ) -If you have the encryption option enabled, the serialized array will be -encrypted before being stored in the cookie, making the data highly -secure and impervious to being read or altered by someone. More info -regarding encryption can be :doc:`found here <encryption>`, although -the Session class will take care of initializing and encrypting the data -automatically. - -Note: Session cookies are only updated every five minutes by default to -reduce processor load. If you repeatedly reload a page you'll notice -that the "last activity" time only updates if five minutes or more has -passed since the last time the cookie was written. This time is -configurable by changing the $config['sess_time_to_update'] line in -your system/config/config.php file. +.. note:: Sessions are only updated every five minutes by default to + reduce processor load. If you repeatedly reload a page you'll notice + that the "last activity" time only updates if five minutes or more has + passed since the last time the cookie was written. This time is + configurable by changing the $config['sess_time_to_update'] line in + your system/config/config.php file. Retrieving Session Data ======================= @@ -106,7 +92,7 @@ fetch. For example, to fetch the session ID you will do this:: $session_id = $this->session->userdata('session_id'); -.. note:: The function returns FALSE (boolean) if the item you are +.. note:: The function returns NULL if the item you are trying to access does not exist. Adding Custom Session Data @@ -117,7 +103,7 @@ to it and it will be stored in the user's cookie. Why would you want to do this? Here's one example: Let's say a particular user logs into your site. Once authenticated, you -could add their username and email address to the session cookie, making +could add their username and email address to the session, making that data globally available to you without having to run a database query when you need it. @@ -144,11 +130,11 @@ supports this syntax. $this->session->set_userdata('some_name', 'some_value'); +If you want to verify that a userdata value exists, call has_userdata(). -.. note:: Cookies can only hold 4KB of data, so be careful not to exceed - the capacity. The encryption process in particular produces a longer - data string than the original so keep careful track of how much data you - are storing. +:: + + $this->session->has_userdata('some_name'); Retrieving All Session Data =========================== @@ -195,8 +181,8 @@ available for the next server request, and are then automatically cleared. These can be very useful, and are typically used for informational or status messages (for example: "record 2 deleted"). -Note: Flash variables are prefaced with "flash\_" so avoid this prefix -in your own session names. +.. note:: Flash variables are prefaced with "flash\_" so avoid this prefix + in your own session names. To add flashdata:: @@ -222,9 +208,162 @@ additional request, you can do so using the keep_flashdata() function. $this->session->keep_flashdata('item'); +Tempdata +======== + +CodeIgniter also supports "tempdata", or session data with a specific +expiration time. After the value expires, or the session expires or is +deleted, the value is automatically removed. + +To add tempdata:: + + $expire = 300; // Expire in 5 minutes + + $this->session->set_tempdata('item', 'value', $expire); + +You can also pass an array to set_tempdata():: + + $tempdata = array('newuser' => TRUE, 'message' => 'Thanks for joining!'); + + $this->session->set_tempdata($tempdata, '', $expire); + +.. note:: If the expiration is omitted or set to 0, the default expiration of + 5 minutes will be used. + +To read a tempdata variable:: + + $this->session->tempdata('item'); + +If you need to remove a tempdata value before it expires, +use unset_tempdata():: + + $this->session->unset_tempdata('item'); + +Destroying a Session +==================== + +To clear the current session:: + + $this->session->sess_destroy(); + +.. note:: This function should be the last one called, and even flash + variables will no longer be available. If you only want some items + destroyed and not all, use unset_userdata(). + +Session Preferences +=================== + +You'll find the following Session related preferences in your +application/config/config.php file: + +=========================== =============== =========================== ========================================================================== +Preference Default Options Description +=========================== =============== =========================== ========================================================================== +**sess_driver** cookie cookie/native/*custom* The initial session driver to load. +**sess_valid_drivers** cookie, native None Additional valid drivers which may be loaded. +**sess_cookie_name** ci_session None The name you want the session cookie saved as (data for Cookie driver or + session ID for Native driver). +**sess_expiration** 7200 None The number of seconds you would like the session to last. The default + value is 2 hours (7200 seconds). If you would like a non-expiring + session set the value to zero: 0 +**sess_expire_on_close** FALSE TRUE/FALSE (boolean) Whether to cause the session to expire automatically when the browser + window is closed. +**sess_encrypt_cookie** FALSE TRUE/FALSE (boolean) Whether to encrypt the session data (Cookie driver only). +**sess_use_database** FALSE TRUE/FALSE (boolean) Whether to save the session data to a database. You must create the + table before enabling this option (Cookie driver only). +**sess_table_name** ci_sessions Any valid SQL table name The name of the session database table (Cookie driver only). +**sess_time_to_update** 300 Time in seconds This options controls how often the session class will regenerate itself + and create a new session id. +**sess_match_ip** FALSE TRUE/FALSE (boolean) Whether to match the user's IP address when reading the session data. + Note that some ISPs dynamically changes the IP, so if you want a + non-expiring session you will likely set this to FALSE. +**sess_match_useragent** TRUE TRUE/FALSE (boolean) Whether to match the User Agent when reading the session data. +=========================== =============== =========================== ========================================================================== + +In addition to the values above, the cookie and native drivers apply the +following configuration values shared by the :doc:`Input <input>` and +:doc:`Security <security>` classes: + +=========================== =============== ========================================================================== +Preference Default Description +=========================== =============== ========================================================================== +**cookie_prefix** '' Set a cookie name prefix in order to avoid name collisions +**cookie_domain** '' The domain for which the session is applicable +**cookie_path** / The path to which the session is applicable +=========================== =============== ========================================================================== + +Session Drivers +=============== + +By default, the `Cookie Driver`_ is loaded when a session is initialized. +However, any valid driver may be selected with the $config['sess_driver'] +line in your config.php file. + +The session driver library comes with the cookie and native drivers +installed, and `Custom Drivers`_ may also be installed by the user. + +Typically, only one driver will be used at a time, but CodeIgniter does +support loading multiple drivers. If a specific valid driver is called, it +will be automatically loaded. Or, an additional driver may be explicitly +loaded by calling load_driver():: + + $this->session->load_driver('native'); + +The Session library keeps track of the most recently selected driver to call +for driver methods. Normally, session class methods are called directly on +the parent class, as illustrated above. However, any methods called through +a specific driver will select that driver before invoking the parent method. + +So, alternation between multiple drivers can be achieved by specifying which +driver to use for each call:: + + $this->session->native->set_userdata('foo', 'bar'); + + $this->session->cookie->userdata('foo'); + + $this->session->native->unset_userdata('foo'); + +Notice in the previous example that the *native* userdata value 'foo' +would be set to 'bar', which would NOT be returned by the call for +the *cookie* userdata 'foo', nor would the *cookie* value be unset by +the call to unset the *native* 'foo' value. The drivers maintain independent +sets of values, regardless of key names. + +A specific driver may also be explicitly selected for use by pursuant +methods with the select_driver() call:: + + $this->session->select_driver('native'); + + $this->session->userdata('item'); // Uses the native driver + +Cookie Driver +------------- + +The Cookie driver stores session information for each user as serialized +(and optionally encrypted) data in a cookie. It can also store the session +data in a database table for added security, as this permits the session ID +in the user's cookie to be matched against the stored session ID. By default +only the cookie is saved. If you choose to use the database option you'll +need to create the session table as indicated below. + +If you have the encryption option enabled, the serialized array will be +encrypted before being stored in the cookie, making the data highly +secure and impervious to being read or altered by someone. More info +regarding encryption can be :doc:`found here <encryption>`, although +the Session class will take care of initializing and encrypting the data +automatically. + +.. note:: Even if you are not using encrypted sessions, you must set + an :doc:`encryption key <./encryption>` in your config file which is used + to aid in preventing session data manipulation. + +.. note:: Cookies can only hold 4KB of data, so be careful not to exceed + the capacity. The encryption process in particular produces a longer + data string than the original so keep careful track of how much data you + are storing. Saving Session Data to a Database -================================= +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ While the session data array stored in the user's cookie contains a Session ID, unless you store session data in a database there is no way @@ -267,44 +406,83 @@ session class:: $config['sess_table_name'] = 'ci_sessions'; -.. note:: The Session class has built-in garbage collection which clears +.. note:: The Cookie driver has built-in garbage collection which clears out expired sessions so you do not need to write your own routine to do it. -Destroying a Session -==================== +Native Driver +------------- -To clear the current session:: +The Native driver relies on native PHP sessions to store data in the +$_SESSION superglobal array. All stored values continue to be available +through $_SESSION, but flash- and temp- data items carry special prefixes. - $this->session->sess_destroy(); +Custom Drivers +-------------- -.. note:: This function should be the last one called, and even flash - variables will no longer be available. If you only want some items - destroyed and not all, use unset_userdata(). +You may also :doc:`create your own <../general/creating_drivers>` custom +session drivers. A session driver basically manages an array of name/value +pairs with some sort of storage mechanism. -Session Preferences -=================== +To make a new driver, extend CI_Session_driver. Overload the initialize() +method and read or create session data. Then implement a save handler to +write changed data to storage (sess_save), a destroy handler to remove +deleted data (sess_destroy), a regenerate handler to make a new session ID +(sess_regenerate), and an access handler to expose the data (get_userdata). +Your initial class might look like:: -You'll find the following Session related preferences in your -application/config/config.php file: + class CI_Session_custom extends CI_Session_driver { + protected function initialize() + { + // Read existing session data or create a new one + } + + public function sess_save() + { + // Save current data to storage + } + + public function sess_destroy() + { + // Destroy the current session and clean up storage + } + + public function sess_regenerate() + { + // Create new session ID + } + + public function &get_userdata() + { + // Return a reference to your userdata array + } + } + +Notice that get_userdata() returns a reference so the parent library is +accessing the same array the driver object is using. This saves memory +and avoids synchronization issues during usage. + +Put your driver in the libraries/Session/drivers folder anywhere in your +package paths. This includes the application directory, the system directory, +or any path you add with $CI->load->add_package_path(). Your driver must be +named CI_Session_<name>, and your filename must be Session_<name>.php, +preferably also capitalized, such as:: + + CI_Session_foo in libraries/Session/drivers/Session_foo.php + +Then specify the driver by setting 'sess_driver' in your config.php file or as a +parameter when loading the CI_Session object:: + + $config['sess_driver'] = 'foo'; + +OR:: + + $CI->load->driver('session', array('sess_driver' => 'foo')); + +The driver specified by 'sess_driver' is automatically included as a valid +driver. However, if you want to make a custom driver available as an option +without making it the initially loaded driver, set 'sess_valid_drivers' in +your config.php file to an array including your driver name:: + + $config['sess_valid_drivers'] = array('sess_driver'); -=========================== =============== =========================== ========================================================================== -Preference Default Options Description -=========================== =============== =========================== ========================================================================== -**sess_cookie_name** ci_session None The name you want the session cookie saved as. -**sess_expiration** 7200 None The number of seconds you would like the session to last. The default - value is 2 hours (7200 seconds). If you would like a non-expiring - session set the value to zero: 0 -**sess_expire_on_close** FALSE TRUE/FALSE (boolean) Whether to cause the session to expire automatically when the browser - window is closed. -**sess_encrypt_cookie** FALSE TRUE/FALSE (boolean) Whether to encrypt the session data. -**sess_use_database** FALSE TRUE/FALSE (boolean) Whether to save the session data to a database. You must create the - table before enabling this option. -**sess_table_name** ci_sessions Any valid SQL table name The name of the session database table. -**sess_time_to_update** 300 Time in seconds This options controls how often the session class will regenerate itself - and create a new session id. -**sess_match_ip** FALSE TRUE/FALSE (boolean) Whether to match the user's IP address when reading the session data. - Note that some ISPs dynamically changes the IP, so if you want a - non-expiring session you will likely set this to FALSE. -**sess_match_useragent** TRUE TRUE/FALSE (boolean) Whether to match the User Agent when reading the session data. -=========================== =============== =========================== ==========================================================================
\ No newline at end of file |