video/user_guide/helpers/url_helper.html

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  57
  58 <h1>URL Helper</h1>
  59
  60 <p>The URL Helper file contains functions that assist in working with URLs.</p>
  61
  62
  63 <h2>Loading this Helper</h2>
  64
  65 <p>This helper is loaded using the following code:</p>
  66 <code>$this->load->helper('url');</code>
  67
  68 <p>The following functions are available:</p>
  69
  70 <h2>site_url()</h2>
  71
  72 <p>Returns your site URL, as specified in your config file.  The index.php file (or whatever you have set as your
  73 site <dfn>index_page</dfn> in your config file) will be added to the URL, as will any URI segments you pass to the function, and the <dfn>url_suffix</dfn> as set in your config file.</p>
  74
  75 <p>You are encouraged to use this function any time you need to generate a local URL so that your pages become more portable
  76 in the event your URL changes.</p>
  77
  78 <p>Segments can be optionally passed to the function as a string or an array.  Here is a string example:</p>
  79
  80 <code>echo site_url("news/local/123");</code>
  81
  82 <p>The above example would return something like: http://example.com/index.php/news/local/123</p>
  83
  84 <p>Here is an example of segments passed as an array:</p>
  85
  86 <code>
  87 $segments = array('news', 'local', '123');<br />
  88 <br />
  89 echo site_url($segments);</code>
  90
  91
  92 <h2>base_url()</h2>
  93 <p>Returns your site base URL, as specified in your config file.  Example:</p>
  94 <code>echo base_url();</code>
  95
  96 <p>This function returns the same thing as site_url, without the <dfn>index_page</dfn> or <dfn>url_suffix</dfn> being appended.</p>
  97
  98 <p>Also like site_url, you can supply segments as a string or an array.  Here is a string example:</p>
  99
 100 <code>echo base_url("blog/post/123");</code>
 101
 102 <p>The above example would return something like: http://example.com/blog/post/123</p>
 103
 104 <p>This is useful because unlike site_url(), you can supply a string to a file, such as an image or stylesheet.  For example:</p>
 105
 106 <code>echo base_url("images/icons/edit.png");</code>
 107
 108 <p>This would give you something like: http://example.com/images/icons/edit.png</p>
 109
 110
 111 <h2>current_url()</h2>
 112 <p>Returns the full URL (including segments) of the page being currently viewed.</p>
 113
 114
 115 <h2>uri_string()</h2>
 116 <p>Returns the URI segments of any page that contains this function.  For example, if your URL was this:</p>
 117 <code>http://some-site.com/blog/comments/123</code>
 118
 119 <p>The function would return:</p>
 120 <code>/blog/comments/123</code>
 121
 122
 123 <h2>index_page()</h2>
 124 <p>Returns your site "index" page, as specified in your config file.  Example:</p>
 125 <code>echo index_page();</code>
 126
 127
 128
 129 <h2>anchor()</h2>
 130
 131 <p>Creates a standard HTML anchor link based on your local site URL:</p>
 132
 133 <code>&lt;a href="http://example.com">Click Here&lt;/a></code>
 134
 135 <p>The tag has three optional parameters:</p>
 136
 137 <code>anchor(<var>uri segments</var>, <var>text</var>, <var>attributes</var>)</code>
 138
 139 <p>The first parameter can contain any segments you wish appended to the URL.  As with the <dfn>site_url()</dfn> function above,
 140 segments can be a string or an array.</p>
 141
 142 <p><strong>Note:</strong>&nbsp; If you are building links that are internal to your application do not include the base URL (http://...).  This
 143 will be added automatically from the information specified in your config file. Include only the URI segments you wish appended to the URL.</p>
 144
 145 <p>The second segment is the text you would like the link to say.  If you leave it blank, the URL will be used.</p>
 146
 147 <p>The third parameter can contain a list of attributes you would like added to the link.  The attributes can be a simple string or an associative array.</p>
 148
 149 <p>Here are some examples:</p>
 150
 151 <code>echo anchor('news/local/123', 'My News', 'title="News title"');</code>
 152
 153 <p>Would produce: &lt;a href="http://example.com/index.php/news/local/123" title="News title">My News&lt;/a></p>
 154
 155 <code>echo anchor('news/local/123', 'My News', array('title' => 'The best news!'));</code>
 156
 157 <p>Would produce: &lt;a href="http://example.com/index.php/news/local/123" title="The best news!">My News&lt;/a></p>
 158
 159
 160 <h2>anchor_popup()</h2>
 161
 162 <p>Nearly identical to the <dfn>anchor()</dfn> function except that it opens the URL in a new window.
 163
 164 You can specify JavaScript window attributes in the third parameter to control how the window is opened. If
 165 the third parameter is not set it will simply open a new window with your own browser settings.  Here is an example
 166 with attributes:</p>
 167
 168 <code>
 169
 170 $atts = array(<br />
 171 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'width'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;=> '800',<br />
 172 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'height'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;=> '600',<br />
 173 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'scrollbars' => 'yes',<br />
 174 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'status'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;=> 'yes',<br />
 175 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'resizable'&nbsp;&nbsp;=> 'yes',<br />
 176 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'screenx'&nbsp;&nbsp;&nbsp;&nbsp;=> '0',<br />
 177 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'screeny'&nbsp;&nbsp;&nbsp;&nbsp;=> '0'<br />
 178 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;);<br />
 179 <br />
 180 echo anchor_popup('news/local/123', 'Click Me!', $atts);</code>
 181
 182 <p>Note: The above attributes are the function defaults so you only need to set the ones that are different from what you need.
 183 If you want the function to use all of its defaults simply pass an empty array in the third parameter:</p>
 184
 185 <code>echo anchor_popup('news/local/123', 'Click Me!', array());</code>
 186
 187
 188 <h2>mailto()</h2>
 189
 190 <p>Creates a standard HTML email link.  Usage example:</p>
 191
 192 <code>echo mailto('me@my-site.com', 'Click Here to Contact Me');</code>
 193
 194 <p>As with the <dfn>anchor()</dfn> tab above, you can set attributes using the third parameter.</p>
 195
 196
 197 <h2>safe_mailto()</h2>
 198
 199 <p>Identical to the above function except it writes an obfuscated version of the mailto tag using ordinal numbers
 200 written with JavaScript to help prevent the email address from being harvested by spam bots.</p>
 201
 202
 203 <h2>auto_link()</h2>
 204
 205 <p>Automatically turns URLs and email addresses contained in a string into links.  Example:</p>
 206
 207 <code>$string = auto_link($string);</code>
 208
 209 <p>The second parameter determines whether URLs and emails are converted or just one or the other.  Default behavior is both
 210 if the parameter is not specified.  Email links are encoded as safe_mailto() as shown above.</p>
 211
 212 <p>Converts only URLs:</p>
 213 <code>$string = auto_link($string, 'url');</code>
 214
 215 <p>Converts only Email addresses:</p>
 216 <code>$string = auto_link($string, 'email');</code>
 217
 218 <p>The third parameter determines whether links are shown in a new window.  The value can be TRUE or FALSE (boolean):</p>
 219 <code>$string = auto_link($string, 'both', TRUE);</code>
 220
 221
 222 <h2>url_title()</h2>
 223 <p>Takes a string as input and creates a human-friendly URL string. This is useful if, for example, you have a blog
 224 in which you'd like to use the title of your entries in the URL.  Example:</p>
 225
 226 <code>$title = "What's wrong with CSS?";<br />
 227 <br />
 228 $url_title = url_title($title);<br />
 229 <br />
 230 // Produces:  Whats-wrong-with-CSS
 231 </code>
 232
 233
 234 <p>The second parameter determines the word delimiter.  By default dashes are used.</p>
 235
 236 <code>$title = "What's wrong with CSS?";<br />
 237 <br />
 238 $url_title = url_title($title, '_');<br />
 239 <br />
 240 // Produces:  Whats_wrong_with_CSS
 241 </code>
 242
 243 <p>The third parameter determines whether or not lowercase characters are forced.  By default they are not.  Options are boolean <dfn>TRUE</dfn>/<dfn>FALSE</dfn>:</p>
 244
 245 <code>$title = "What's wrong with CSS?";<br />
 246 <br />
 247 $url_title = url_title($title, '_', TRUE);<br />
 248 <br />
 249 // Produces:  whats_wrong_with_css
 250 </code>
 251
 252 <h3>prep_url()</h3>
 253 <p>This function will add <kbd>http://</kbd> in the event that a scheme is missing from a URL.  Pass the URL string to the function like this:</p>
 254 <code>
 255 $url = "example.com";<br /><br />
 256 $url = prep_url($url);</code>
 257
 258
 259
 260
 261 <h2>redirect()</h2>
 262
 263 <p>Does a "header redirect" to the URI specified. If you specify the full site URL that link will be build, but for local links simply providing the URI segments
 264 to the controller you want to direct to will create the link. The function will build the URL based on your config file values.</p>
 265
 266 <p>The optional second parameter allows you to choose between the "location"
 267 method (default) or the "refresh" method.  Location is faster, but on Windows servers it can sometimes be a problem.  The optional third parameter allows you to send a specific HTTP Response Code - this could be used for example to create 301 redirects for search engine purposes. The default Response Code is 302. The third parameter is <em>only</em> available with 'location' redirects, and not 'refresh'. Examples:</p>
 268
 269 <code>if ($logged_in == FALSE)<br />
 270 {<br />
 271 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;redirect('/login/form/', 'refresh');<br />
 272 }<br />
 273 <br />
 274 // with 301 redirect<br />
 275 redirect('/article/13', 'location', 301);</code>
 276
 277 <p class="important"><strong>Note:</strong> In order for this function to work it must be used before anything is outputted
 278 to the browser since it utilizes server headers.<br />
 279 <strong>Note:</strong> For  very fine grained control over headers, you should use the <a href="../libraries/output.html">Output  Library</a>'s set_header() function.</p>
 280
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