mirror of
https://github.com/yiisoft/yii2.git
synced 2025-10-31 10:39:59 +08:00
81 lines
2.7 KiB
Markdown
81 lines
2.7 KiB
Markdown
Helpers
|
|
=======
|
|
|
|
> Note: This section is under development.
|
|
|
|
Yii provides many classes that help simplify common coding tasks, such as string or array manipulations,
|
|
HTML code generation, and so on. These helper classes are organized under the `yii\helpers` namespace and
|
|
are all static classes (meaning they contain only static properties and methods and should not be instantiated).
|
|
|
|
You use a helper class by directly calling one of its static methods, like the following:
|
|
|
|
```php
|
|
use yii\helpers\Html;
|
|
|
|
echo Html::encode('Test > test');
|
|
```
|
|
|
|
> Note: To support [customizing helper classes](#customizing-helper-classes), Yii breaks each core helper class
|
|
into two classes: a base class (e.g. `BaseArrayHelper`) and a concrete class (e.g. `ArrayHelper`).
|
|
When you use a helper, you should only use the concrete version and never use the base class.
|
|
|
|
|
|
Core Helper Classes
|
|
-------------------
|
|
|
|
The following core helper classes are provided in the Yii releases:
|
|
|
|
- [ArrayHelper](helper-array.md)
|
|
- Console
|
|
- FileHelper
|
|
- FormatConverter
|
|
- [Html](helper-html.md)
|
|
- HtmlPurifier
|
|
- Imagine (provided by yii2-imagine extension)
|
|
- Inflector
|
|
- Json
|
|
- Markdown
|
|
- StringHelper
|
|
- [Url](helper-url.md)
|
|
- VarDumper
|
|
|
|
|
|
Customizing Helper Classes <span id="customizing-helper-classes"></span>
|
|
--------------------------
|
|
|
|
To customize a core helper class (e.g. [[yii\helpers\ArrayHelper]]), you should create a new class extending
|
|
from the helpers corresponding base class (e.g. [[yii\helpers\BaseArrayHelper]]) and name your class the same
|
|
as the corresponding concrete class (e.g. [[yii\helpers\ArrayHelper]]), including its namespace. This class
|
|
will then be set up to replace the original implementation of the framework.
|
|
|
|
The following example shows how to customize the [[yii\helpers\ArrayHelper::merge()|merge()]] method of the
|
|
[[yii\helpers\ArrayHelper]] class:
|
|
|
|
```php
|
|
<?php
|
|
|
|
namespace yii\helpers;
|
|
|
|
class ArrayHelper extends BaseArrayHelper
|
|
{
|
|
public static function merge($a, $b)
|
|
{
|
|
// your custom implementation
|
|
}
|
|
}
|
|
```
|
|
|
|
Save your class in a file named `ArrayHelper.php`. The file can be in any directory, for example `@app/components`.
|
|
|
|
Next, in your application's [entry script](structure-entry-scripts.md), add the following line of code
|
|
after including the `yii.php` file to tell the [Yii class autoloader](concept-autoloading.md) to load your custom
|
|
class instead of the original helper class from the framework:
|
|
|
|
```php
|
|
Yii::$classMap['yii\helpers\ArrayHelper'] = '@app/components/ArrayHelper.php';
|
|
```
|
|
|
|
Note that customizing of helper classes is only useful if you want to change the behavior of an existing function
|
|
of the helpers. If you want to add additional functions to use in your application, you may be better off creating a separate
|
|
helper for that.
|