php - Zend 框架 : How to create an abstract view helper for other view helpers to extend?

Question

我需要在我的 Zend Framework 应用程序中创建一些自定义表单元素(带有自定义 View 助手)。问题是他们每个人都如此相似。我想创建一个基本 View 帮助器类，每个类都可以扩展它，并实现我需要的抽象函数。

解决方案:

因此，如果我的 Picker 元素是抽象类，而 ContactPicker 和 OrganizationPicker 是扩展类...

表单元素:

class My_Form_Element_ContactPicker extends My_Form_Element_Picker
{
    /**
     * Default form view helper to use for rendering
     * @var string
     */
    public $helper = "contactPickerElement";
}

View 助手:

class My_View_Helper_ContactPickerElement extends My_View_Helper_PickerElement
{
    public function contactPickerElement($name, $value = null, $attribs = null)
    {
        // I don't need to do anything in this function.
        // I only need the parent to do all the work.
        return parent::pickerElement($name, $value, $attribs);
    }

    protected function myAbstractFunctionThatMustBeImplemented()
    {
        // This function will do all the work specific to this extending class.
        $model = new ContactModel();
        return $model->foobar;
    }
}

这是抽象 View 助手:

abstract class Evanta_View_Helper_PickerElement extends Zend_View_Helper_FormElement
{
   /**
    * This function would have been called automatically, but since it's being extended...
    * Any extending classes must remember to manually call this function 
    */
   public function modalPickerElement($name, $value = null, $attribs = null)
    {
        $html = 'My picker element HTML';
        return $html;
    }
    
    /**
     * This function must be implemented by any extending classes
     */
    abstract protected function myAbstractFunctionThatMustBeImplemented();
}

Answer 1

在 Bootstrap 中的某个位置，您需要定义表单资源的去向，我建议使用自动加载器:

$autoloader->addResourceType('default_form', 'forms/', 'Form');

我加载自动加载器的整个方法如下所示

protected function _initAutoload()
{
    $autoloader = new Zend_Application_Module_Autoloader(array(
            'namespace' => 'Default_',
            'basePath'  => $this->_root,
        ));

    // Here a define a resource named 'default_form', this can be anything,
    // 2nd param is the path relative to my application folder,
    // and 3rd param is the prefix for the classes inside that folder
    $autoloader->addResourceType('default_form', 'forms/', 'Form');

    Zend_Loader_Autoloader::getInstance()->setFallbackAutoloader(true);

    return $autoloader;
}

然后，您可以在此 forms 文件夹中创建一个名为 Element 的文件夹，然后创建一个名为 Default_Form_Element_Picker.php 的文件并定义该类，您可以可以重写诸如 isValid()、setValues()、getValue()、loadDefaultDecorators() 和 __construct()

Default_Form_Element_Picker extends Zend_Form_Element_Xhtml {

}        

您可以通过创建名为 Default_Form_Element_ContactPicker.php 和 Default_Form_Element_OrganizationPicker.php 的文件来扩展此类以创建其他表单元素

Default_Form_Element_ContactPicker extends Default_Form_Element_Picker {

}

Default_Form_Element_OrganizationPicker extends Default_Form_Element_Picker {

}

您还可以在此处添加一个用于创建表单的类，将其命名为 Default_Form_A.php

Default_Form_A extends Zend_Form {

    public function __construct()
    {
        // create form elements here suing Zend_Form_Element and your new Custom Elements
    }
}

文件结构

 application 
 |--forms   
 |----Default_Form_A.php
 |----Element
 |------ Default_Form_Element_Picker.php
 |------ Default_Form_Element_ContactPicker.php
 |------ Default_Form_Element_OrganizationPicker.php