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  1. 

  2. 

  3. <!DOCTYPE html>
    4. 

  4. <!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
    5. 

  5. <!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
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  6. <head>
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  7.   <meta charset="utf-8">
    8. 

  8.   <meta name="viewport" content="width=device-width, initial-scale=1.0">
    9. 

  9.   
    10. 

  10.   <title>Helper Functions &mdash; CodeIgniter 3.1.11 documentation</title>
    11. 

  11.   
    12. 

  12. 

  13.   
    14. 

  14.   
    15. 

  15.     <link rel="shortcut icon" href="../_static/ci-icon.ico"/>
    16. 

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  17. 

  18.   
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  19.   <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'>
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  21.   
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  26. 

  27.   
    28. 

  28.   
    29. 

  29.     <link rel="stylesheet" href="../_static/css/citheme.css" type="text/css" />
    30. 

  30.   
    31. 

  31. 

  32.   
    33. 

  33.         <link rel="index" title="Index"
    34. 

  34.               href="../genindex.html"/>
    35. 

  35.         <link rel="search" title="Search" href="../search.html"/>
    36. 

  36.     <link rel="top" title="CodeIgniter 3.1.11 documentation" href="../index.html"/>
    37. 

  37.         <link rel="up" title="General Topics" href="index.html"/>
    38. 

  38.         <link rel="next" title="Using CodeIgniter Libraries" href="libraries.html"/>
    39. 

  39.         <link rel="prev" title="Models" href="models.html"/> 
    40. 

  40. 

  41.   
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  42.   <script src="https://cdnjs.cloudflare.com/ajax/libs/modernizr/2.6.2/modernizr.min.js"></script>
    43. 

  43. 

  44. </head>
    45. 

  45. 

  46. <body class="wy-body-for-nav" role="document">
    47. 

  47. 

  48.   <div id="nav">
    49. 

  49.   <div id="nav_inner">
    50. 

  50.     
    51. 

  51.     
    52. 

  52.     
    53. 

  53.       <div id="pulldown-menu" class="ciNav">
    54. 

  54.         <ul>
    55. 

  55. <li class="toctree-l1"><a class="reference internal" href="welcome.html">Welcome to CodeIgniter</a></li>
    56. 

  56. </ul>
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  57. <ul>
    58. 

  58. <li class="toctree-l1"><a class="reference internal" href="../installation/index.html">Installation Instructions</a><ul>
    59. 

  59. <li class="toctree-l2"><a class="reference internal" href="../installation/downloads.html">Downloading CodeIgniter</a></li>
    60. 

  60. <li class="toctree-l2"><a class="reference internal" href="../installation/index.html">Installation Instructions</a></li>
    61. 

  61. <li class="toctree-l2"><a class="reference internal" href="../installation/upgrading.html">Upgrading From a Previous Version</a></li>
    62. 

  62. <li class="toctree-l2"><a class="reference internal" href="../installation/troubleshooting.html">Troubleshooting</a></li>
    63. 

  63. </ul>
    64. 

  64. </li>
    65. 

  65. </ul>
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  67. <li class="toctree-l1"><a class="reference internal" href="../overview/index.html">CodeIgniter Overview</a><ul>
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    69. 

  69. <li class="toctree-l2"><a class="reference internal" href="../overview/at_a_glance.html">CodeIgniter at a Glance</a></li>
    70. 

  70. <li class="toctree-l2"><a class="reference internal" href="../overview/features.html">Supported Features</a></li>
    71. 

  71. <li class="toctree-l2"><a class="reference internal" href="../overview/appflow.html">Application Flow Chart</a></li>
    72. 

  72. <li class="toctree-l2"><a class="reference internal" href="../overview/mvc.html">Model-View-Controller</a></li>
    73. 

  73. <li class="toctree-l2"><a class="reference internal" href="../overview/goals.html">Architectural Goals</a></li>
    74. 

  74. </ul>
    75. 

  75. </li>
    76. 

  76. </ul>
    77. 

  77. <ul>
    78. 

  78. <li class="toctree-l1"><a class="reference internal" href="../tutorial/index.html">Tutorial</a><ul>
    79. 

  79. <li class="toctree-l2"><a class="reference internal" href="../tutorial/static_pages.html">Static pages</a></li>
    80. 

  80. <li class="toctree-l2"><a class="reference internal" href="../tutorial/news_section.html">News section</a></li>
    81. 

  81. <li class="toctree-l2"><a class="reference internal" href="../tutorial/create_news_items.html">Create news items</a></li>
    82. 

  82. <li class="toctree-l2"><a class="reference internal" href="../tutorial/conclusion.html">Conclusion</a></li>
    83. 

  83. </ul>
    84. 

  84. </li>
    85. 

  85. </ul>
    86. 

  86. <ul>
    87. 

  87. <li class="toctree-l1"><a class="reference internal" href="../contributing/index.html">Contributing to CodeIgniter</a><ul>
    88. 

  88. <li class="toctree-l2"><a class="reference internal" href="../documentation/index.html">Writing CodeIgniter Documentation</a></li>
    89. 

  89. <li class="toctree-l2"><a class="reference internal" href="../DCO.html">Developer’s Certificate of Origin 1.1</a></li>
    90. 

  90. </ul>
    91. 

  91. </li>
    92. 

  92. </ul>
    93. 

  93. <ul class="current">
    94. 

  94. <li class="toctree-l1 current"><a class="reference internal" href="index.html">General Topics</a><ul class="current">
    95. 

  95. <li class="toctree-l2"><a class="reference internal" href="urls.html">CodeIgniter URLs</a></li>
    96. 

  96. <li class="toctree-l2"><a class="reference internal" href="controllers.html">Controllers</a></li>
    97. 

  97. <li class="toctree-l2"><a class="reference internal" href="reserved_names.html">Reserved Names</a></li>
    98. 

  98. <li class="toctree-l2"><a class="reference internal" href="views.html">Views</a></li>
    99. 

  99. <li class="toctree-l2"><a class="reference internal" href="models.html">Models</a></li>
    100. 

  100. <li class="toctree-l2 current"><a class="current reference internal" href="#">Helpers</a></li>
    101. 

  101. <li class="toctree-l2"><a class="reference internal" href="libraries.html">Using CodeIgniter Libraries</a></li>
    102. 

  102. <li class="toctree-l2"><a class="reference internal" href="creating_libraries.html">Creating Libraries</a></li>
    103. 

  103. <li class="toctree-l2"><a class="reference internal" href="drivers.html">Using CodeIgniter Drivers</a></li>
    104. 

  104. <li class="toctree-l2"><a class="reference internal" href="creating_drivers.html">Creating Drivers</a></li>
    105. 

  105. <li class="toctree-l2"><a class="reference internal" href="core_classes.html">Creating Core System Classes</a></li>
    106. 

  106. <li class="toctree-l2"><a class="reference internal" href="ancillary_classes.html">Creating Ancillary Classes</a></li>
    107. 

  107. <li class="toctree-l2"><a class="reference internal" href="hooks.html">Hooks - Extending the Framework Core</a></li>
    108. 

  108. <li class="toctree-l2"><a class="reference internal" href="autoloader.html">Auto-loading Resources</a></li>
    109. 

  109. <li class="toctree-l2"><a class="reference internal" href="common_functions.html">Common Functions</a></li>
    110. 

  110. <li class="toctree-l2"><a class="reference internal" href="compatibility_functions.html">Compatibility Functions</a></li>
    111. 

  111. <li class="toctree-l2"><a class="reference internal" href="routing.html">URI Routing</a></li>
    112. 

  112. <li class="toctree-l2"><a class="reference internal" href="errors.html">Error Handling</a></li>
    113. 

  113. <li class="toctree-l2"><a class="reference internal" href="caching.html">Caching</a></li>
    114. 

  114. <li class="toctree-l2"><a class="reference internal" href="profiling.html">Profiling Your Application</a></li>
    115. 

  115. <li class="toctree-l2"><a class="reference internal" href="cli.html">Running via the CLI</a></li>
    116. 

  116. <li class="toctree-l2"><a class="reference internal" href="managing_apps.html">Managing your Applications</a></li>
    117. 

  117. <li class="toctree-l2"><a class="reference internal" href="environments.html">Handling Multiple Environments</a></li>
    118. 

  118. <li class="toctree-l2"><a class="reference internal" href="alternative_php.html">Alternate PHP Syntax for View Files</a></li>
    119. 

  119. <li class="toctree-l2"><a class="reference internal" href="security.html">Security</a></li>
    120. 

  120. <li class="toctree-l2"><a class="reference internal" href="styleguide.html">PHP Style Guide</a></li>
    121. 

  121. </ul>
    122. 

  122. </li>
    123. 

  123. </ul>
    124. 

  124. <ul>
    125. 

  125. <li class="toctree-l1"><a class="reference internal" href="../libraries/index.html">Libraries</a><ul>
    126. 

  126. <li class="toctree-l2"><a class="reference internal" href="../libraries/benchmark.html">Benchmarking Class</a></li>
    127. 

  127. <li class="toctree-l2"><a class="reference internal" href="../libraries/caching.html">Caching Driver</a></li>
    128. 

  128. <li class="toctree-l2"><a class="reference internal" href="../libraries/calendar.html">Calendaring Class</a></li>
    129. 

  129. <li class="toctree-l2"><a class="reference internal" href="../libraries/cart.html">Shopping Cart Class</a></li>
    130. 

  130. <li class="toctree-l2"><a class="reference internal" href="../libraries/config.html">Config Class</a></li>
    131. 

  131. <li class="toctree-l2"><a class="reference internal" href="../libraries/email.html">Email Class</a></li>
    132. 

  132. <li class="toctree-l2"><a class="reference internal" href="../libraries/encrypt.html">Encrypt Class</a></li>
    133. 

  133. <li class="toctree-l2"><a class="reference internal" href="../libraries/encryption.html">Encryption Library</a></li>
    134. 

  134. <li class="toctree-l2"><a class="reference internal" href="../libraries/file_uploading.html">File Uploading Class</a></li>
    135. 

  135. <li class="toctree-l2"><a class="reference internal" href="../libraries/form_validation.html">Form Validation</a></li>
    136. 

  136. <li class="toctree-l2"><a class="reference internal" href="../libraries/ftp.html">FTP Class</a></li>
    137. 

  137. <li class="toctree-l2"><a class="reference internal" href="../libraries/image_lib.html">Image Manipulation Class</a></li>
    138. 

  138. <li class="toctree-l2"><a class="reference internal" href="../libraries/input.html">Input Class</a></li>
    139. 

  139. <li class="toctree-l2"><a class="reference internal" href="../libraries/javascript.html">Javascript Class</a></li>
    140. 

  140. <li class="toctree-l2"><a class="reference internal" href="../libraries/language.html">Language Class</a></li>
    141. 

  141. <li class="toctree-l2"><a class="reference internal" href="../libraries/loader.html">Loader Class</a></li>
    142. 

  142. <li class="toctree-l2"><a class="reference internal" href="../libraries/migration.html">Migrations Class</a></li>
    143. 

  143. <li class="toctree-l2"><a class="reference internal" href="../libraries/output.html">Output Class</a></li>
    144. 

  144. <li class="toctree-l2"><a class="reference internal" href="../libraries/pagination.html">Pagination Class</a></li>
    145. 

  145. <li class="toctree-l2"><a class="reference internal" href="../libraries/parser.html">Template Parser Class</a></li>
    146. 

  146. <li class="toctree-l2"><a class="reference internal" href="../libraries/security.html">Security Class</a></li>
    147. 

  147. <li class="toctree-l2"><a class="reference internal" href="../libraries/sessions.html">Session Library</a></li>
    148. 

  148. <li class="toctree-l2"><a class="reference internal" href="../libraries/table.html">HTML Table Class</a></li>
    149. 

  149. <li class="toctree-l2"><a class="reference internal" href="../libraries/trackback.html">Trackback Class</a></li>
    150. 

  150. <li class="toctree-l2"><a class="reference internal" href="../libraries/typography.html">Typography Class</a></li>
    151. 

  151. <li class="toctree-l2"><a class="reference internal" href="../libraries/unit_testing.html">Unit Testing Class</a></li>
    152. 

  152. <li class="toctree-l2"><a class="reference internal" href="../libraries/uri.html">URI Class</a></li>
    153. 

  153. <li class="toctree-l2"><a class="reference internal" href="../libraries/user_agent.html">User Agent Class</a></li>
    154. 

  154. <li class="toctree-l2"><a class="reference internal" href="../libraries/xmlrpc.html">XML-RPC and XML-RPC Server Classes</a></li>
    155. 

  155. <li class="toctree-l2"><a class="reference internal" href="../libraries/zip.html">Zip Encoding Class</a></li>
    156. 

  156. </ul>
    157. 

  157. </li>
    158. 

  158. </ul>
    159. 

  159. <ul>
    160. 

  160. <li class="toctree-l1"><a class="reference internal" href="../database/index.html">Database Reference</a><ul>
    161. 

  161. <li class="toctree-l2"><a class="reference internal" href="../database/examples.html">Quick Start: Usage Examples</a></li>
    162. 

  162. <li class="toctree-l2"><a class="reference internal" href="../database/configuration.html">Database Configuration</a></li>
    163. 

  163. <li class="toctree-l2"><a class="reference internal" href="../database/connecting.html">Connecting to a Database</a></li>
    164. 

  164. <li class="toctree-l2"><a class="reference internal" href="../database/queries.html">Running Queries</a></li>
    165. 

  165. <li class="toctree-l2"><a class="reference internal" href="../database/results.html">Generating Query Results</a></li>
    166. 

  166. <li class="toctree-l2"><a class="reference internal" href="../database/helpers.html">Query Helper Functions</a></li>
    167. 

  167. <li class="toctree-l2"><a class="reference internal" href="../database/query_builder.html">Query Builder Class</a></li>
    168. 

  168. <li class="toctree-l2"><a class="reference internal" href="../database/transactions.html">Transactions</a></li>
    169. 

  169. <li class="toctree-l2"><a class="reference internal" href="../database/metadata.html">Getting MetaData</a></li>
    170. 

  170. <li class="toctree-l2"><a class="reference internal" href="../database/call_function.html">Custom Function Calls</a></li>
    171. 

  171. <li class="toctree-l2"><a class="reference internal" href="../database/caching.html">Query Caching</a></li>
    172. 

  172. <li class="toctree-l2"><a class="reference internal" href="../database/forge.html">Database Manipulation with Database Forge</a></li>
    173. 

  173. <li class="toctree-l2"><a class="reference internal" href="../database/utilities.html">Database Utilities Class</a></li>
    174. 

  174. <li class="toctree-l2"><a class="reference internal" href="../database/db_driver_reference.html">Database Driver Reference</a></li>
    175. 

  175. </ul>
    176. 

  176. </li>
    177. 

  177. </ul>
    178. 

  178. <ul>
    179. 

  179. <li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a><ul>
    180. 

  180. <li class="toctree-l2"><a class="reference internal" href="../helpers/array_helper.html">Array Helper</a></li>
    181. 

  181. <li class="toctree-l2"><a class="reference internal" href="../helpers/captcha_helper.html">CAPTCHA Helper</a></li>
    182. 

  182. <li class="toctree-l2"><a class="reference internal" href="../helpers/cookie_helper.html">Cookie Helper</a></li>
    183. 

  183. <li class="toctree-l2"><a class="reference internal" href="../helpers/date_helper.html">Date Helper</a></li>
    184. 

  184. <li class="toctree-l2"><a class="reference internal" href="../helpers/directory_helper.html">Directory Helper</a></li>
    185. 

  185. <li class="toctree-l2"><a class="reference internal" href="../helpers/download_helper.html">Download Helper</a></li>
    186. 

  186. <li class="toctree-l2"><a class="reference internal" href="../helpers/email_helper.html">Email Helper</a></li>
    187. 

  187. <li class="toctree-l2"><a class="reference internal" href="../helpers/file_helper.html">File Helper</a></li>
    188. 

  188. <li class="toctree-l2"><a class="reference internal" href="../helpers/form_helper.html">Form Helper</a></li>
    189. 

  189. <li class="toctree-l2"><a class="reference internal" href="../helpers/html_helper.html">HTML Helper</a></li>
    190. 

  190. <li class="toctree-l2"><a class="reference internal" href="../helpers/inflector_helper.html">Inflector Helper</a></li>
    191. 

  191. <li class="toctree-l2"><a class="reference internal" href="../helpers/language_helper.html">Language Helper</a></li>
    192. 

  192. <li class="toctree-l2"><a class="reference internal" href="../helpers/number_helper.html">Number Helper</a></li>
    193. 

  193. <li class="toctree-l2"><a class="reference internal" href="../helpers/path_helper.html">Path Helper</a></li>
    194. 

  194. <li class="toctree-l2"><a class="reference internal" href="../helpers/security_helper.html">Security Helper</a></li>
    195. 

  195. <li class="toctree-l2"><a class="reference internal" href="../helpers/smiley_helper.html">Smiley Helper</a></li>
    196. 

  196. <li class="toctree-l2"><a class="reference internal" href="../helpers/string_helper.html">String Helper</a></li>
    197. 

  197. <li class="toctree-l2"><a class="reference internal" href="../helpers/text_helper.html">Text Helper</a></li>
    198. 

  198. <li class="toctree-l2"><a class="reference internal" href="../helpers/typography_helper.html">Typography Helper</a></li>
    199. 

  199. <li class="toctree-l2"><a class="reference internal" href="../helpers/url_helper.html">URL Helper</a></li>
    200. 

  200. <li class="toctree-l2"><a class="reference internal" href="../helpers/xml_helper.html">XML Helper</a></li>
    201. 

  201. </ul>
    202. 

  202. </li>
    203. 

  203. </ul>
    204. 

  204. 

  205.       </div>
    206. 

  206.     
    207. 

  207.       
    208. 

  208.   </div>
    209. 

  209. </div>
    210. 

  210. <div id="nav2">
    211. 

  211.   <a href="#" id="openToc">
    212. 

  212.     <img src="data:image/jpeg;base64,/9j/4AAQSkZJRgABAgAAZABkAAD/7AARRHVja3kAAQAEAAAARgAA/+4ADkFkb2JlAGTAAAAAAf/bAIQABAMDAwMDBAMDBAYEAwQGBwUEBAUHCAYGBwYGCAoICQkJCQgKCgwMDAwMCgwMDQ0MDBERERERFBQUFBQUFBQUFAEEBQUIBwgPCgoPFA4ODhQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQU/8AAEQgAKwCaAwERAAIRAQMRAf/EAHsAAQAABwEBAAAAAAAAAAAAAAABAwQFBgcIAgkBAQAAAAAAAAAAAAAAAAAAAAAQAAEDAwICBwYEAgsAAAAAAAIBAwQAEQUSBiEHkROTVNQWGDFBUVIUCHEiMtOUFWGBobHRQlMkZIRVEQEAAAAAAAAAAAAAAAAAAAAA/9oADAMBAAIRAxEAPwDSC+ygkOOaUoKigUCgUCgUCgUCgUCgUCgUCgkuGguIP9FBMFb0Hqg7We+3jlmIqqYFf4ub+/QYlnOR/LqIBKGFUbf8qWv971BytQXXE7Y3Lnm3HsFhp2TaZJAdchRXpIgSpdEJWxJEW3xoKV7F5OMy7JkQn2o7D6w33XGjEAkoiqrJEqIiOIiKuhePCgqp22dyYyS3CyWHnQ5joG61HkRnmnTbaFSMhExRVQRRVJU9iUHjE7ez+fJ0MFipmUNhBV8YUd2SoIV9KkjQla9ltegttBdPLW4/qocL+UTfrMiHW4+P9M71shuyrqaHTcxsl7jegpsji8nh5ZwMvDfgTm0RTjSmjYdFCS6KoOIipdFunCgmNYTMv457MMY6U7iI6oMieDDhRm1VbIhuoOkbqtuK0Hpzb+eZcYZexUxt6UyUqK2cd0SdjtgrhOgijcgERUlJOCIl6CpgbP3blRI8XgMjNARAyKNDfeRBdFDBVUAXgQrqH4pxoJTu2NysY97LP4ac1io5q1InHFeGO24LnVKJuKOkSQ/yKir+rh7aCLG1dzypZQI2FnvTgccYOM3FeN0XWERXAUEFVQgQkUktdLpegm+Td3/Xli/L+S/mYNJIOF9G/wBeLKrZHFb0akG6W1WtQWSg3Dyg5e7V3fipE3O4/wCrktyzYA+ufas2LbZIlmnAT2kvuoN1wft95augilglX/tzP3qCu9O3LL/wV/i5v79BvmTADq14UGu91467Z6U9y0HzH/ncj/U/sT/CgynZG7I2NezpZGUjIycJkYkZSG+uQ81pbBNKLxJfjwoMqZ3/ALYHl35AJ7/cuwHcu5k7r1Q5pHetBjquqVVJWGxj9Zrtcl/Ggy3dHMvauR3HFZj5nHNxSyW5JISYDMoIwx8tFIGHZhPNaykGapr6rUAiicEoMG21lMRj8buPAz8xhJrr7uOeiPTCyAwXUaGR1mgozbTusOsFLEiJ7fbQa/h7gcjy2H3V6xppwDNtUSxCJIqp7valBuWVzJ22xuCROXNNZiJkMtms0DbjUkAZjzoDrTMd9dDRI44ZC2YsrYdKWP2WDT2S3N9dNdlRYrGMYc06IURXSYb0igrpWS485xVNS6nF4rwslkoMwnbpgZLB7bmt5uMweAhDEl4B5uSLzzqTnnyVpW2jaJHRMSIjdDiiotvy3DOE5rYTEbkl5yFn28k7JyG4c7AU2HtLH1uKfaiMPI40CdYbpNtmLdwTSn5rewLNld+7TLdeal4WarWBkbVKBjgdElMJJwAAY5fl4kB3b1fp4XvagsGS3FjJfLzDNtS8aeXx7LzT7TyzByQE5PccRGRC0ZRUDRV6y62vbjagzLmJzS2vuPK43JY6aP1TW6Jz+RIWyFtyC06y3EkiiinAo7YCqfq1AqqnGgsOH3lhZO8d1pmcpB8j5XIm9OYlBJSQ/FSS4427DKO0RC8AlcEMhFdViRR1WDWR5t3WXVuL1d106kG9vdeye2g60+1FDyW0shIcXVpyroXt8I8dfd+NB1vioAdWnD3UF1+gD4UFc6CEKpagxXN43rwJLUHz7yX2c8zokt9uHlsPIhA4aRnnHJTLptIS6CNsY7iASpxUUMkReGpfbQW0vtN5pitvrsN28rwtBD0nc0+/Yft5XhaB6TuaXfsP28rwtA9J3NPv2H7eV4Wgek7mn37D9vK8LQPSdzT79h+3leFoHpO5pd+w/byvC0D0nc0u/Yft5XhaB6TuaXfsP28rwtA9J3NLv2H7eV4Wgek7ml37D9vK8LQPSdzS79h+3leFoHpO5p9+w/byvC0E9r7Reazy2HIYVPxkS/CUHVn26cosxyv2g7h89LYmZSXOenvLEQ1YaQ222RATcQCP8rSGqqA8S02W2pQ6FhMoAIlqCtsnwoCpdKClejI4i3Sgtb+GBxVuNBSFt1pV/RQefLjPyUDy4z8lA8uM/JQPLjPyUDy4z8lA8uM/JQPLjPyUDy4z8lA8uM/JQPLjPyUDy4z8lA8utJ/koJ7WCbBU/LQXOPAFq1koK8B0pag90CggtBBf6qB0UDooHRQOigdFA6KB0UDooHRQOigdFA6KB0UDooI0EaBQf//Z" title="Toggle Table of Contents" alt="Toggle Table of Contents" />
    213. 

  213.   </a>
    214. 

  214. </div>
    215. 

  215. 

  216.   <div class="wy-grid-for-nav">
    217. 

  217. 

  218.     
    219. 

  219.     <nav data-toggle="wy-nav-shift" class="wy-nav-side">
    220. 

  220.       <div class="wy-side-nav-search">
    221. 

  221.         
    222. 

  222.           <a href="../index.html" class="fa fa-home"> CodeIgniter</a>
    223. 

  223.         
    224. 

  224.         
    225. 

  225. <div role="search">
    226. 

  226.   <form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
    227. 

  227.     <input type="text" name="q" placeholder="Search docs" />
    228. 

  228.     <input type="hidden" name="check_keywords" value="yes" />
    229. 

  229.     <input type="hidden" name="area" value="default" />
    230. 

  230.   </form>
    231. 

  231. </div>
    232. 

  232.       </div>
    233. 

  233. 

  234.       <div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
    235. 

  235.         
    236. 

  236.           
    237. 

  237.           
    238. 

  238.               <ul>
    239. 

  239. <li class="toctree-l1"><a class="reference internal" href="welcome.html">Welcome to CodeIgniter</a></li>
    240. 

  240. </ul>
    241. 

  241. <ul>
    242. 

  242. <li class="toctree-l1"><a class="reference internal" href="../installation/index.html">Installation Instructions</a><ul>
    243. 

  243. <li class="toctree-l2"><a class="reference internal" href="../installation/downloads.html">Downloading CodeIgniter</a></li>
    244. 

  244. <li class="toctree-l2"><a class="reference internal" href="../installation/index.html">Installation Instructions</a></li>
    245. 

  245. <li class="toctree-l2"><a class="reference internal" href="../installation/upgrading.html">Upgrading From a Previous Version</a></li>
    246. 

  246. <li class="toctree-l2"><a class="reference internal" href="../installation/troubleshooting.html">Troubleshooting</a></li>
    247. 

  247. </ul>
    248. 

  248. </li>
    249. 

  249. </ul>
    250. 

  250. <ul>
    251. 

  251. <li class="toctree-l1"><a class="reference internal" href="../overview/index.html">CodeIgniter Overview</a><ul>
    252. 

  252. <li class="toctree-l2"><a class="reference internal" href="../overview/getting_started.html">Getting Started</a></li>
    253. 

  253. <li class="toctree-l2"><a class="reference internal" href="../overview/at_a_glance.html">CodeIgniter at a Glance</a></li>
    254. 

  254. <li class="toctree-l2"><a class="reference internal" href="../overview/features.html">Supported Features</a></li>
    255. 

  255. <li class="toctree-l2"><a class="reference internal" href="../overview/appflow.html">Application Flow Chart</a></li>
    256. 

  256. <li class="toctree-l2"><a class="reference internal" href="../overview/mvc.html">Model-View-Controller</a></li>
    257. 

  257. <li class="toctree-l2"><a class="reference internal" href="../overview/goals.html">Architectural Goals</a></li>
    258. 

  258. </ul>
    259. 

  259. </li>
    260. 

  260. </ul>
    261. 

  261. <ul>
    262. 

  262. <li class="toctree-l1"><a class="reference internal" href="../tutorial/index.html">Tutorial</a><ul>
    263. 

  263. <li class="toctree-l2"><a class="reference internal" href="../tutorial/static_pages.html">Static pages</a></li>
    264. 

  264. <li class="toctree-l2"><a class="reference internal" href="../tutorial/news_section.html">News section</a></li>
    265. 

  265. <li class="toctree-l2"><a class="reference internal" href="../tutorial/create_news_items.html">Create news items</a></li>
    266. 

  266. <li class="toctree-l2"><a class="reference internal" href="../tutorial/conclusion.html">Conclusion</a></li>
    267. 

  267. </ul>
    268. 

  268. </li>
    269. 

  269. </ul>
    270. 

  270. <ul>
    271. 

  271. <li class="toctree-l1"><a class="reference internal" href="../contributing/index.html">Contributing to CodeIgniter</a><ul>
    272. 

  272. <li class="toctree-l2"><a class="reference internal" href="../documentation/index.html">Writing CodeIgniter Documentation</a></li>
    273. 

  273. <li class="toctree-l2"><a class="reference internal" href="../DCO.html">Developer’s Certificate of Origin 1.1</a></li>
    274. 

  274. </ul>
    275. 

  275. </li>
    276. 

  276. </ul>
    277. 

  277. <ul class="current">
    278. 

  278. <li class="toctree-l1 current"><a class="reference internal" href="index.html">General Topics</a><ul class="current">
    279. 

  279. <li class="toctree-l2"><a class="reference internal" href="urls.html">CodeIgniter URLs</a></li>
    280. 

  280. <li class="toctree-l2"><a class="reference internal" href="controllers.html">Controllers</a></li>
    281. 

  281. <li class="toctree-l2"><a class="reference internal" href="reserved_names.html">Reserved Names</a></li>
    282. 

  282. <li class="toctree-l2"><a class="reference internal" href="views.html">Views</a></li>
    283. 

  283. <li class="toctree-l2"><a class="reference internal" href="models.html">Models</a></li>
    284. 

  284. <li class="toctree-l2 current"><a class="current reference internal" href="#">Helpers</a></li>
    285. 

  285. <li class="toctree-l2"><a class="reference internal" href="libraries.html">Using CodeIgniter Libraries</a></li>
    286. 

  286. <li class="toctree-l2"><a class="reference internal" href="creating_libraries.html">Creating Libraries</a></li>
    287. 

  287. <li class="toctree-l2"><a class="reference internal" href="drivers.html">Using CodeIgniter Drivers</a></li>
    288. 

  288. <li class="toctree-l2"><a class="reference internal" href="creating_drivers.html">Creating Drivers</a></li>
    289. 

  289. <li class="toctree-l2"><a class="reference internal" href="core_classes.html">Creating Core System Classes</a></li>
    290. 

  290. <li class="toctree-l2"><a class="reference internal" href="ancillary_classes.html">Creating Ancillary Classes</a></li>
    291. 

  291. <li class="toctree-l2"><a class="reference internal" href="hooks.html">Hooks - Extending the Framework Core</a></li>
    292. 

  292. <li class="toctree-l2"><a class="reference internal" href="autoloader.html">Auto-loading Resources</a></li>
    293. 

  293. <li class="toctree-l2"><a class="reference internal" href="common_functions.html">Common Functions</a></li>
    294. 

  294. <li class="toctree-l2"><a class="reference internal" href="compatibility_functions.html">Compatibility Functions</a></li>
    295. 

  295. <li class="toctree-l2"><a class="reference internal" href="routing.html">URI Routing</a></li>
    296. 

  296. <li class="toctree-l2"><a class="reference internal" href="errors.html">Error Handling</a></li>
    297. 

  297. <li class="toctree-l2"><a class="reference internal" href="caching.html">Caching</a></li>
    298. 

  298. <li class="toctree-l2"><a class="reference internal" href="profiling.html">Profiling Your Application</a></li>
    299. 

  299. <li class="toctree-l2"><a class="reference internal" href="cli.html">Running via the CLI</a></li>
    300. 

  300. <li class="toctree-l2"><a class="reference internal" href="managing_apps.html">Managing your Applications</a></li>
    301. 

  301. <li class="toctree-l2"><a class="reference internal" href="environments.html">Handling Multiple Environments</a></li>
    302. 

  302. <li class="toctree-l2"><a class="reference internal" href="alternative_php.html">Alternate PHP Syntax for View Files</a></li>
    303. 

  303. <li class="toctree-l2"><a class="reference internal" href="security.html">Security</a></li>
    304. 

  304. <li class="toctree-l2"><a class="reference internal" href="styleguide.html">PHP Style Guide</a></li>
    305. 

  305. </ul>
    306. 

  306. </li>
    307. 

  307. </ul>
    308. 

  308. <ul>
    309. 

  309. <li class="toctree-l1"><a class="reference internal" href="../libraries/index.html">Libraries</a><ul>
    310. 

  310. <li class="toctree-l2"><a class="reference internal" href="../libraries/benchmark.html">Benchmarking Class</a></li>
    311. 

  311. <li class="toctree-l2"><a class="reference internal" href="../libraries/caching.html">Caching Driver</a></li>
    312. 

  312. <li class="toctree-l2"><a class="reference internal" href="../libraries/calendar.html">Calendaring Class</a></li>
    313. 

  313. <li class="toctree-l2"><a class="reference internal" href="../libraries/cart.html">Shopping Cart Class</a></li>
    314. 

  314. <li class="toctree-l2"><a class="reference internal" href="../libraries/config.html">Config Class</a></li>
    315. 

  315. <li class="toctree-l2"><a class="reference internal" href="../libraries/email.html">Email Class</a></li>
    316. 

  316. <li class="toctree-l2"><a class="reference internal" href="../libraries/encrypt.html">Encrypt Class</a></li>
    317. 

  317. <li class="toctree-l2"><a class="reference internal" href="../libraries/encryption.html">Encryption Library</a></li>
    318. 

  318. <li class="toctree-l2"><a class="reference internal" href="../libraries/file_uploading.html">File Uploading Class</a></li>
    319. 

  319. <li class="toctree-l2"><a class="reference internal" href="../libraries/form_validation.html">Form Validation</a></li>
    320. 

  320. <li class="toctree-l2"><a class="reference internal" href="../libraries/ftp.html">FTP Class</a></li>
    321. 

  321. <li class="toctree-l2"><a class="reference internal" href="../libraries/image_lib.html">Image Manipulation Class</a></li>
    322. 

  322. <li class="toctree-l2"><a class="reference internal" href="../libraries/input.html">Input Class</a></li>
    323. 

  323. <li class="toctree-l2"><a class="reference internal" href="../libraries/javascript.html">Javascript Class</a></li>
    324. 

  324. <li class="toctree-l2"><a class="reference internal" href="../libraries/language.html">Language Class</a></li>
    325. 

  325. <li class="toctree-l2"><a class="reference internal" href="../libraries/loader.html">Loader Class</a></li>
    326. 

  326. <li class="toctree-l2"><a class="reference internal" href="../libraries/migration.html">Migrations Class</a></li>
    327. 

  327. <li class="toctree-l2"><a class="reference internal" href="../libraries/output.html">Output Class</a></li>
    328. 

  328. <li class="toctree-l2"><a class="reference internal" href="../libraries/pagination.html">Pagination Class</a></li>
    329. 

  329. <li class="toctree-l2"><a class="reference internal" href="../libraries/parser.html">Template Parser Class</a></li>
    330. 

  330. <li class="toctree-l2"><a class="reference internal" href="../libraries/security.html">Security Class</a></li>
    331. 

  331. <li class="toctree-l2"><a class="reference internal" href="../libraries/sessions.html">Session Library</a></li>
    332. 

  332. <li class="toctree-l2"><a class="reference internal" href="../libraries/table.html">HTML Table Class</a></li>
    333. 

  333. <li class="toctree-l2"><a class="reference internal" href="../libraries/trackback.html">Trackback Class</a></li>
    334. 

  334. <li class="toctree-l2"><a class="reference internal" href="../libraries/typography.html">Typography Class</a></li>
    335. 

  335. <li class="toctree-l2"><a class="reference internal" href="../libraries/unit_testing.html">Unit Testing Class</a></li>
    336. 

  336. <li class="toctree-l2"><a class="reference internal" href="../libraries/uri.html">URI Class</a></li>
    337. 

  337. <li class="toctree-l2"><a class="reference internal" href="../libraries/user_agent.html">User Agent Class</a></li>
    338. 

  338. <li class="toctree-l2"><a class="reference internal" href="../libraries/xmlrpc.html">XML-RPC and XML-RPC Server Classes</a></li>
    339. 

  339. <li class="toctree-l2"><a class="reference internal" href="../libraries/zip.html">Zip Encoding Class</a></li>
    340. 

  340. </ul>
    341. 

  341. </li>
    342. 

  342. </ul>
    343. 

  343. <ul>
    344. 

  344. <li class="toctree-l1"><a class="reference internal" href="../database/index.html">Database Reference</a><ul>
    345. 

  345. <li class="toctree-l2"><a class="reference internal" href="../database/examples.html">Quick Start: Usage Examples</a></li>
    346. 

  346. <li class="toctree-l2"><a class="reference internal" href="../database/configuration.html">Database Configuration</a></li>
    347. 

  347. <li class="toctree-l2"><a class="reference internal" href="../database/connecting.html">Connecting to a Database</a></li>
    348. 

  348. <li class="toctree-l2"><a class="reference internal" href="../database/queries.html">Running Queries</a></li>
    349. 

  349. <li class="toctree-l2"><a class="reference internal" href="../database/results.html">Generating Query Results</a></li>
    350. 

  350. <li class="toctree-l2"><a class="reference internal" href="../database/helpers.html">Query Helper Functions</a></li>
    351. 

  351. <li class="toctree-l2"><a class="reference internal" href="../database/query_builder.html">Query Builder Class</a></li>
    352. 

  352. <li class="toctree-l2"><a class="reference internal" href="../database/transactions.html">Transactions</a></li>
    353. 

  353. <li class="toctree-l2"><a class="reference internal" href="../database/metadata.html">Getting MetaData</a></li>
    354. 

  354. <li class="toctree-l2"><a class="reference internal" href="../database/call_function.html">Custom Function Calls</a></li>
    355. 

  355. <li class="toctree-l2"><a class="reference internal" href="../database/caching.html">Query Caching</a></li>
    356. 

  356. <li class="toctree-l2"><a class="reference internal" href="../database/forge.html">Database Manipulation with Database Forge</a></li>
    357. 

  357. <li class="toctree-l2"><a class="reference internal" href="../database/utilities.html">Database Utilities Class</a></li>
    358. 

  358. <li class="toctree-l2"><a class="reference internal" href="../database/db_driver_reference.html">Database Driver Reference</a></li>
    359. 

  359. </ul>
    360. 

  360. </li>
    361. 

  361. </ul>
    362. 

  362. <ul>
    363. 

  363. <li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a><ul>
    364. 

  364. <li class="toctree-l2"><a class="reference internal" href="../helpers/array_helper.html">Array Helper</a></li>
    365. 

  365. <li class="toctree-l2"><a class="reference internal" href="../helpers/captcha_helper.html">CAPTCHA Helper</a></li>
    366. 

  366. <li class="toctree-l2"><a class="reference internal" href="../helpers/cookie_helper.html">Cookie Helper</a></li>
    367. 

  367. <li class="toctree-l2"><a class="reference internal" href="../helpers/date_helper.html">Date Helper</a></li>
    368. 

  368. <li class="toctree-l2"><a class="reference internal" href="../helpers/directory_helper.html">Directory Helper</a></li>
    369. 

  369. <li class="toctree-l2"><a class="reference internal" href="../helpers/download_helper.html">Download Helper</a></li>
    370. 

  370. <li class="toctree-l2"><a class="reference internal" href="../helpers/email_helper.html">Email Helper</a></li>
    371. 

  371. <li class="toctree-l2"><a class="reference internal" href="../helpers/file_helper.html">File Helper</a></li>
    372. 

  372. <li class="toctree-l2"><a class="reference internal" href="../helpers/form_helper.html">Form Helper</a></li>
    373. 

  373. <li class="toctree-l2"><a class="reference internal" href="../helpers/html_helper.html">HTML Helper</a></li>
    374. 

  374. <li class="toctree-l2"><a class="reference internal" href="../helpers/inflector_helper.html">Inflector Helper</a></li>
    375. 

  375. <li class="toctree-l2"><a class="reference internal" href="../helpers/language_helper.html">Language Helper</a></li>
    376. 

  376. <li class="toctree-l2"><a class="reference internal" href="../helpers/number_helper.html">Number Helper</a></li>
    377. 

  377. <li class="toctree-l2"><a class="reference internal" href="../helpers/path_helper.html">Path Helper</a></li>
    378. 

  378. <li class="toctree-l2"><a class="reference internal" href="../helpers/security_helper.html">Security Helper</a></li>
    379. 

  379. <li class="toctree-l2"><a class="reference internal" href="../helpers/smiley_helper.html">Smiley Helper</a></li>
    380. 

  380. <li class="toctree-l2"><a class="reference internal" href="../helpers/string_helper.html">String Helper</a></li>
    381. 

  381. <li class="toctree-l2"><a class="reference internal" href="../helpers/text_helper.html">Text Helper</a></li>
    382. 

  382. <li class="toctree-l2"><a class="reference internal" href="../helpers/typography_helper.html">Typography Helper</a></li>
    383. 

  383. <li class="toctree-l2"><a class="reference internal" href="../helpers/url_helper.html">URL Helper</a></li>
    384. 

  384. <li class="toctree-l2"><a class="reference internal" href="../helpers/xml_helper.html">XML Helper</a></li>
    385. 

  385. </ul>
    386. 

  386. </li>
    387. 

  387. </ul>
    388. 

  388. 

  389.           
    390. 

  390.         
    391. 

  391.       </div>
    392. 

  392.       &nbsp;
    393. 

  393.     </nav>
    394. 

  394. 

  395.     <section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
    396. 

  396. 

  397.       
    398. 

  398.       <nav class="wy-nav-top" role="navigation" aria-label="top navigation">
    399. 

  399.         <i data-toggle="wy-nav-top" class="fa fa-bars"></i>
    400. 

  400.         <a href="../index.html">CodeIgniter</a>
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  413.     <li>Helper Functions</li>
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    425. 

  425.   <div class="section" id="helper-functions">
    426. 

  426. <h1>Helper Functions<a class="headerlink" href="#helper-functions" title="Permalink to this headline">¶</a></h1>
    427. 

  427. <p>Helpers, as the name suggests, help you with tasks. Each helper file is
    428. 

  428. simply a collection of functions in a particular category. There are <strong>URL
    429. 

  429. Helpers</strong>, that assist in creating links, there are Form Helpers that help
    430. 

  430. you create form elements, <strong>Text Helpers</strong> perform various text formatting
    431. 

  431. routines, <strong>Cookie Helpers</strong> set and read cookies, File Helpers help you
    432. 

  432. deal with files, etc.</p>
    433. 

  433. <p>Unlike most other systems in CodeIgniter, Helpers are not written in an
    434. 

  434. Object Oriented format. They are simple, procedural functions. Each
    435. 

  435. helper function performs one specific task, with no dependence on other
    436. 

  436. functions.</p>
    437. 

  437. <p>CodeIgniter does not load Helper Files by default, so the first step in
    438. 

  438. using a Helper is to load it. Once loaded, it becomes globally available
    439. 

  439. in your <a class="reference internal" href="controllers.html"><span class="doc">controller</span></a> and
    440. 

  440. <a class="reference internal" href="views.html"><span class="doc">views</span></a>.</p>
    441. 

  441. <p>Helpers are typically stored in your <strong>system/helpers</strong>, or
    442. 

  442. <strong>application/helpers directory</strong>. CodeIgniter will look first in your
    443. 

  443. <strong>application/helpers directory</strong>. If the directory does not exist or the
    444. 

  444. specified helper is not located there CI will instead look in your
    445. 

  445. global <em>system/helpers/</em> directory.</p>
    446. 

  446. <div class="section" id="loading-a-helper">
    447. 

  447. <h2>Loading a Helper<a class="headerlink" href="#loading-a-helper" title="Permalink to this headline">¶</a></h2>
    448. 

  448. <p>Loading a helper file is quite simple using the following method:</p>
    449. 

  449. <div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">helper</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">);</span>
    450. 

  450. </pre></div>
    451. 

  451. </div>
    452. 

  452. <p>Where <strong>name</strong> is the file name of the helper, without the .php file
    453. 

  453. extension or the “helper” part.</p>
    454. 

  454. <p>For example, to load the <strong>URL Helper</strong> file, which is named
    455. 

  455. <strong>url_helper.php</strong>, you would do this:</p>
    456. 

  456. <div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">helper</span><span class="p">(</span><span class="s1">&#39;url&#39;</span><span class="p">);</span>
    457. 

  457. </pre></div>
    458. 

  458. </div>
    459. 

  459. <p>A helper can be loaded anywhere within your controller methods (or
    460. 

  460. even within your View files, although that’s not a good practice), as
    461. 

  461. long as you load it before you use it. You can load your helpers in your
    462. 

  462. controller constructor so that they become available automatically in
    463. 

  463. any function, or you can load a helper in a specific function that needs
    464. 

  464. it.</p>
    465. 

  465. <div class="admonition note">
    466. 

  466. <p class="first admonition-title">Note</p>
    467. 

  467. <p class="last">The Helper loading method above does not return a value, so
    468. 

  468. don’t try to assign it to a variable. Just use it as shown.</p>
    469. 

  469. </div>
    470. 

  470. </div>
    471. 

  471. <div class="section" id="loading-multiple-helpers">
    472. 

  472. <h2>Loading Multiple Helpers<a class="headerlink" href="#loading-multiple-helpers" title="Permalink to this headline">¶</a></h2>
    473. 

  473. <p>If you need to load more than one helper you can specify them in an
    474. 

  474. array, like this:</p>
    475. 

  475. <div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">load</span><span class="o">-&gt;</span><span class="na">helper</span><span class="p">(</span>
    476. 

  476.         <span class="k">array</span><span class="p">(</span><span class="s1">&#39;helper1&#39;</span><span class="p">,</span> <span class="s1">&#39;helper2&#39;</span><span class="p">,</span> <span class="s1">&#39;helper3&#39;</span><span class="p">)</span>
    477. 

  477. <span class="p">);</span>
    478. 

  478. </pre></div>
    479. 

  479. </div>
    480. 

  480. </div>
    481. 

  481. <div class="section" id="auto-loading-helpers">
    482. 

  482. <h2>Auto-loading Helpers<a class="headerlink" href="#auto-loading-helpers" title="Permalink to this headline">¶</a></h2>
    483. 

  483. <p>If you find that you need a particular helper globally throughout your
    484. 

  484. application, you can tell CodeIgniter to auto-load it during system
    485. 

  485. initialization. This is done by opening the <strong>application/config/autoload.php</strong>
    486. 

  486. file and adding the helper to the autoload array.</p>
    487. 

  487. </div>
    488. 

  488. <div class="section" id="using-a-helper">
    489. 

  489. <h2>Using a Helper<a class="headerlink" href="#using-a-helper" title="Permalink to this headline">¶</a></h2>
    490. 

  490. <p>Once you’ve loaded the Helper File containing the function you intend to
    491. 

  491. use, you’ll call it the way you would a standard PHP function.</p>
    492. 

  492. <p>For example, to create a link using the <code class="docutils literal"><span class="pre">anchor()</span></code> function in one of
    493. 

  493. your view files you would do this:</p>
    494. 

  494. <div class="highlight-ci"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span> <span class="k">echo</span> <span class="nx">anchor</span><span class="p">(</span><span class="s1">&#39;blog/comments&#39;</span><span class="p">,</span> <span class="s1">&#39;Click Here&#39;</span><span class="p">);</span><span class="cp">?&gt;</span>
    495. 

  495. </pre></div>
    496. 

  496. </div>
    497. 

  497. <p>Where “Click Here” is the name of the link, and “blog/comments” is the
    498. 

  498. URI to the controller/method you wish to link to.</p>
    499. 

  499. </div>
    500. 

  500. <div class="section" id="extending-helpers">
    501. 

  501. <h2>“Extending” Helpers<a class="headerlink" href="#extending-helpers" title="Permalink to this headline">¶</a></h2>
    502. 

  502. <p>To “extend” Helpers, create a file in your <strong>application/helpers/</strong> folder
    503. 

  503. with an identical name to the existing Helper, but prefixed with <strong>MY_</strong>
    504. 

  504. (this item is configurable. See below.).</p>
    505. 

  505. <p>If all you need to do is add some functionality to an existing helper -
    506. 

  506. perhaps add a function or two, or change how a particular helper
    507. 

  507. function operates - then it’s overkill to replace the entire helper with
    508. 

  508. your version. In this case it’s better to simply “extend” the Helper.</p>
    509. 

  509. <div class="admonition note">
    510. 

  510. <p class="first admonition-title">Note</p>
    511. 

  511. <p class="last">The term “extend” is used loosely since Helper functions are
    512. 

  512. procedural and discrete and cannot be extended in the traditional
    513. 

  513. programmatic sense. Under the hood, this gives you the ability to
    514. 

  514. add to or or to replace the functions a Helper provides.</p>
    515. 

  515. </div>
    516. 

  516. <p>For example, to extend the native <strong>Array Helper</strong> you’ll create a file
    517. 

  517. named <strong>application/helpers/MY_array_helper.php</strong>, and add or override
    518. 

  518. functions:</p>
    519. 

  519. <div class="highlight-ci"><div class="highlight"><pre><span></span><span class="c1">// any_in_array() is not in the Array Helper, so it defines a new function</span>
    520. 

  520. <span class="k">function</span> <span class="nf">any_in_array</span><span class="p">(</span><span class="nv">$needle</span><span class="p">,</span> <span class="nv">$haystack</span><span class="p">)</span>
    521. 

  521. <span class="p">{</span>
    522. 

  522.         <span class="nv">$needle</span> <span class="o">=</span> <span class="nb">is_array</span><span class="p">(</span><span class="nv">$needle</span><span class="p">)</span> <span class="o">?</span> <span class="nv">$needle</span> <span class="o">:</span> <span class="k">array</span><span class="p">(</span><span class="nv">$needle</span><span class="p">);</span>
    523. 

  523. 

  524.         <span class="k">foreach</span> <span class="p">(</span><span class="nv">$needle</span> <span class="k">as</span> <span class="nv">$item</span><span class="p">)</span>
    525. 

  525.         <span class="p">{</span>
    526. 

  526.                 <span class="k">if</span> <span class="p">(</span><span class="nb">in_array</span><span class="p">(</span><span class="nv">$item</span><span class="p">,</span> <span class="nv">$haystack</span><span class="p">))</span>
    527. 

  527.                 <span class="p">{</span>
    528. 

  528.                         <span class="k">return</span> <span class="k">TRUE</span><span class="p">;</span>
    529. 

  529.                 <span class="p">}</span>
    530. 

  530.         <span class="p">}</span>
    531. 

  531. 

  532.         <span class="k">return</span> <span class="k">FALSE</span><span class="p">;</span>
    533. 

  533. <span class="p">}</span>
    534. 

  534. 

  535. <span class="c1">// random_element() is included in Array Helper, so it overrides the native function</span>
    536. 

  536. <span class="k">function</span> <span class="nf">random_element</span><span class="p">(</span><span class="nv">$array</span><span class="p">)</span>
    537. 

  537. <span class="p">{</span>
    538. 

  538.         <span class="nb">shuffle</span><span class="p">(</span><span class="nv">$array</span><span class="p">);</span>
    539. 

  539.         <span class="k">return</span> <span class="nb">array_pop</span><span class="p">(</span><span class="nv">$array</span><span class="p">);</span>
    540. 

  540. <span class="p">}</span>
    541. 

  541. </pre></div>
    542. 

  542. </div>
    543. 

  543. <div class="section" id="setting-your-own-prefix">
    544. 

  544. <h3>Setting Your Own Prefix<a class="headerlink" href="#setting-your-own-prefix" title="Permalink to this headline">¶</a></h3>
    545. 

  545. <p>The filename prefix for “extending” Helpers is the same used to extend
    546. 

  546. libraries and core classes. To set your own prefix, open your
    547. 

  547. <strong>application/config/config.php</strong> file and look for this item:</p>
    548. 

  548. <div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$config</span><span class="p">[</span><span class="s1">&#39;subclass_prefix&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="s1">&#39;MY_&#39;</span><span class="p">;</span>
    549. 

  549. </pre></div>
    550. 

  550. </div>
    551. 

  551. <p>Please note that all native CodeIgniter libraries are prefixed with <strong>CI_</strong>
    552. 

  552. so DO NOT use that as your prefix.</p>
    553. 

  553. </div>
    554. 

  554. </div>
    555. 

  555. <div class="section" id="now-what">
    556. 

  556. <h2>Now What?<a class="headerlink" href="#now-what" title="Permalink to this headline">¶</a></h2>
    557. 

  557. <p>In the Table of Contents you’ll find a list of all the available Helper
    558. 

  558. Files. Browse each one to see what they do.</p>
    559. 

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    560. 

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