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Pascal Kriete1f622292011-04-07 12:06:51 -0400[diff] [blame]31<td><h1>CodeIgniter User Guide Version 2.0.2</h1></td>
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59<h1>Array Helper</h1>
60
61<p>The Array Helper file contains functions that assist in working with arrays.</p>
62
63
64<h2>Loading this Helper</h2>
65
66<p>This helper is loaded using the following code:</p>
67<code>$this->load->helper('array');</code>
68
69<p>The following functions are available:</p>
70
71<h2>element()</h2>
72
Razican114ab092011-04-25 17:26:45 +0200[diff] [blame^]73<p>Lets you fetch an item from an array. The function tests whether the array index is set and whether it has a value. If
74a value exists it is returned. If a value does not exist it returns FALSE, or whatever you've specified as the default value via the third parameter. Example:</p>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]75
76<code>
77$array = array('color' => 'red', 'shape' => 'round', 'size' => '');<br />
78<br />
79// returns "red"<br />
80echo element('color', $array);<br />
81<br />
82// returns NULL<br />
83echo element('size', $array, NULL);
84</code>
85
86
87<h2>random_element()</h2>
88
Razican114ab092011-04-25 17:26:45 +0200[diff] [blame^]89<p>Takes an array as input and returns a random element from it. Usage example:</p>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]90
91<code>$quotes = array(<br />
92&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"I find that the harder I work, the more luck I seem to have. - Thomas Jefferson",<br />
93&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"Don't stay in bed, unless you can make money in bed. - George Burns",<br />
94&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"We didn't lose the game; we just ran out of time. - Vince Lombardi",<br />
95&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"If everything seems under control, you're not going fast enough. - Mario Andretti",<br />
96&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"Reality is merely an illusion, albeit a very persistent one. - Albert Einstein",<br />
97&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"Chance favors the prepared mind - Louis Pasteur"<br />
98&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;);<br />
99<br />
100echo random_element($quotes);</code>
101
102
Derek Jones3a082fd2010-10-07 09:38:55 -0500[diff] [blame]103<h2>elements()</h2>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]104
Razican114ab092011-04-25 17:26:45 +0200[diff] [blame^]105<p>Lets you fetch a number of items from an array. The function tests whether each of the array indices is set. If an index does not exist
106it is set to FALSE, or whatever you've specified as the default value via the third parameter. Example:</p>
Derek Jones3a082fd2010-10-07 09:38:55 -0500[diff] [blame]107
108<code>
109$array = array(<br />
110&nbsp;&nbsp;&nbsp;&nbsp;'color' => 'red',<br />
111&nbsp;&nbsp;&nbsp;&nbsp;'shape' => 'round',<br />
112&nbsp;&nbsp;&nbsp;&nbsp;'radius' => '10',<br />
113&nbsp;&nbsp;&nbsp;&nbsp;'diameter' => '20'<br />
114);<br />
115<br />
116$my_shape = elements(array('color', 'shape', 'height'), $array);<br />
117</code>
118
119<p>The above will return the following array:</p>
120
121<code>
122array(<br />
123&nbsp;&nbsp;&nbsp;&nbsp;'color' => 'red',<br />
124&nbsp;&nbsp;&nbsp;&nbsp;'shape' => 'round',<br />
125&nbsp;&nbsp;&nbsp;&nbsp;'height' => FALSE<br />
126);
127</code>
128
129<p>You can set the third parameter to any default value you like:</p>
130
131<code>
132$my_shape = elements(array('color', 'shape', 'height'), $array, NULL);<br />
133</code>
134
135<p>The above will return the following array:</p>
136
137<code>
138array(<br />
139&nbsp;&nbsp;&nbsp;&nbsp;'color' => 'red',<br />
140&nbsp;&nbsp;&nbsp;&nbsp;'shape' => 'round',<br />
141&nbsp;&nbsp;&nbsp;&nbsp;'height' => NULL<br />
142);
143</code>
144
Razican114ab092011-04-25 17:26:45 +0200[diff] [blame^]145<p>This is useful when sending the <kbd>$_POST</kbd> array to one of your Models. This prevents users from
Derek Jones3a082fd2010-10-07 09:38:55 -0500[diff] [blame]146sending additional POST data to be entered into your tables:</p>
147
148<code>
149$this->load->model('post_model');<br />
150<br />
151$this->post_model->update(elements(array('id', 'title', 'content'), $_POST));
152</code>
153
154<p>This ensures that only the id, title and content fields are sent to be updated.</p>
Derek Allard2067d1a2008-11-13 22:59:24 +0000[diff] [blame]155
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