Detailed explanation of the usage of CodeIgniter auxiliary function helper-PHP Tutorial-php.cn

Detailed explanation of the usage of CodeIgniter auxiliary function helper

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Release： 2016-07-25 08:52:59

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$this->load->helper('name');

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where name is the name of the helper function file (without the .php suffix and "helper" part).

For example, to load the URL Helper with the file name url_helper.php, you can use the following statement:

$this->load->helper('url');

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Helper functions can be loaded anywhere in your controller, even Loaded in the View file (we don't recommend this). Please load helper functions before using them. You can load them in your controller constructor so that helper functions are automatically loaded before other functions. You can also load helper functions where they are needed.

Note: The helper function loading function does not return a value, so don't try to assign it to a variable, just use it like this.

3. Load multiple auxiliary functions If you want to load multiple helper functions at once, you can do this:

$this->load->helper( array('helper1', 'helper2', 'helper3') );

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4, automatically load the helper function CodeIgniter can automatically load helper functions for you if you want. You can do this by opening application/config/autoload.php and adding helper functions to the autoload array.

5, use auxiliary functions Once you have loaded the helper function file you want to use, you can use the standard function calling method to use the functions inside. For example, to use the anchor() function to create a link, in a View file you would do this: " blog/comments" is the URI of the link. (Collected and organized by Programmer’s Home bbs.it-home.org) Note: It is best to follow naming conventions for function names in auxiliary functions. If multiple auxiliary function files are loaded at the same time and there are functions with the same name, it will cause a blank page problem in CI (this is also a PHP syntax error).

6, "Extended" auxiliary function If you want to "extend" an original Helper, you can create a new helper in the application/helpers/ directory. The name of the new helper is to add an additional MY_ at the beginning of the name of the "extended" Helper (this is configurable . See below.). If you just add some new functions to the original helper, for example, add one or two new methods, or modify a method; it is not worth rewriting your own helper. In this case, it's better to "extend" an existing helper. The word "extended" is not very appropriate here, because Helper's methods are procedural and discrete and cannot be "extended" in traditional language environments. However, in CodeIgniter, you can add Or modify the helper method. For example, to extend a local existing Array Helper you would create a file: application/helpers/MY_array_helper.php, and add or override some of its methods:

// any_in_array() is not in the Array Helper, so it defines a new function

function any_in_array($needle, $haystack)

{ $needle = (is_array($needle)) ? $needle : array($needle); foreach ($needle as $item)

{

if (in_array($item, $haystack))

{

return TRUE;

}

return FALSE;

// random_element () is included in Array Helper, so it overrides the native function
function random_element($array)
{
shuffle($array);
return array_pop($array);
}
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7 , set the prefix (Prefix) Prefixed files used to "extend" helpers are also extensions to libraries and core classes. In order to set a custom prefix, please open the application/config/config.php file and find:
$config['subclass_prefix'] = 'MY_';

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Note: Since all CodeIgniter's built-in libraries are named with prefixes like CI_, please do not use CI _To customize the prefix.