added elements() to the Array Helper to return elements from an array with specified keys only. Differs from array_intersect_assoc() in that a default value can be provided for keys that do not exist in the supplied array

1 files changed, 51 insertions, 0 deletions

diff --git a/user_guide/helpers/array_helper.html b/user_guide/helpers/array_helper.html
index c0bdd78e3..6d95c4a5f 100644
--- a/user_guide/helpers/array_helper.html
+++ b/user_guide/helpers/array_helper.html
@@ -100,7 +100,58 @@ echo element('size', $array, NULL);
 echo random_element($quotes);</code>
 
 
+<h2>elements()</h2>
 
+<p>Lets you fetch a number of items from an array.  The function tests whether each of the array indices is set.  If an index does not exist
+it is set to FALSE, or whatever you've specified as the default value via the third parameter.  Example:</p>
+
+<code>
+$array = array(<br />
+&nbsp;&nbsp;&nbsp;&nbsp;'color' => 'red',<br />
+&nbsp;&nbsp;&nbsp;&nbsp;'shape' => 'round',<br />
+&nbsp;&nbsp;&nbsp;&nbsp;'radius' => '10',<br />
+&nbsp;&nbsp;&nbsp;&nbsp;'diameter' => '20'<br />
+);<br />
+<br />
+$my_shape = elements(array('color', 'shape', 'height'), $array);<br />
+</code>
+
+<p>The above will return the following array:</p>
+
+<code>
+array(<br />
+&nbsp;&nbsp;&nbsp;&nbsp;'color' => 'red',<br />
+&nbsp;&nbsp;&nbsp;&nbsp;'shape' => 'round',<br />
+&nbsp;&nbsp;&nbsp;&nbsp;'height' => FALSE<br />
+);
+</code>
+
+<p>You can set the third parameter to any default value you like:</p>
+
+<code>
+$my_shape = elements(array('color', 'shape', 'height'), $array, NULL);<br />
+</code>
+
+<p>The above will return the following array:</p>
+
+<code>
+array(<br />
+&nbsp;&nbsp;&nbsp;&nbsp;'color' => 'red',<br />
+&nbsp;&nbsp;&nbsp;&nbsp;'shape' => 'round',<br />
+&nbsp;&nbsp;&nbsp;&nbsp;'height' => NULL<br />
+);
+</code>
+
+<p>This is useful when sending the <kbd>$_POST</kbd> array to one of your Models.  This prevents users from
+sending additional POST data to be entered into your tables:</p>
+
+<code>
+$this->load->model('post_model');<br />
+<br />
+$this->post_model->update(elements(array('id', 'title', 'content'), $_POST));
+</code>
+
+<p>This ensures that only the id, title and content fields are sent to be updated.</p>
 
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