理解 Magento 中的 getChildHtml [英] Understanding getChildHtml in Magento

问题描述

从 2columns-right.phtml 中的以下行

<?php echo $this->getChildHtml('global_messages') ?><?php echo $this->getChildHtml('content') ?>

我无法理解 <?php echo $this->getChildHtml('content') ?> 中的 content 来自哪里.

<?php echo $this->getChildHtml('content') ?>?

调用哪个.phtml文件来显示数据

解决方案

如果我们正在讨论网站的前端，那么您询问的特定行....

getChildHtml('content') ?>

被添加到 app/design/frontend/base/default/layout/page.xml 中的 Magento 布局 XML 中.在 Magento 1.8 版中，您会发现它在第 92-94 行中定义.

<label>主要内容区</label>

通过查看这个block标签的type"属性，我们可以知道这部分布局是什么对象类.它来自核心"模块，属于块类型文本列表.此 Mage_Core_Block_Text_List 的类名.(app/code/core/Mage/Core/Block/Text/List.php).文本列表只是块容器，其目的是在其中存储额外的子块.您可以将任意数量的子块添加到文本列表中，它们将按照添加顺序或分配顺序进行渲染.

因此，为了回答您的问题，没有呈现 $this->getChildHtml('content') 内容的视图脚本(.phtml 文件). 已经添加到这个块，它们本身可能有与之关联的视图脚本.要找出那些是什么视图脚本，您必须找到添加了块的布局 XML.

例如，如果我将以下布局文件添加到我网站主题的前端:

<布局><默认><参考名称=内容"><block type="core/template" name="my_view_script" template="hello/world.phtml"/></参考></默认></布局>

上面的代码会将对象类为 Mage_Core_Block_Template 的块添加到名为内容"的块中(这恰好是您询问的那个).然后 Magento 将在以下位置按顺序查找视图脚本:

app/design/frontend/PACKAGE_NAME/THEME_NAME/template/hello/world.phtmlapp/design/frontend/PACKAGE_NAME/default/template/hello/world.phtmlapp/design/frontend/base/default/template/hello/world.phtml

找到的第一个就是它将使用的那个.如果没有找到视图脚本，Magento 将在 var/logs/system.log(默认日志文件设置)中记录一个错误，指出没有找到视图脚本.不会发生块的输出.

请注意，根据您在 System -> Configuration -> (General) Design 中的设置，Magento 可能会查看其他 package/theme 位置.还有其他情况，例如自定义主题"是针对单个 CMS 页面、目录类别或目录产品更改的字段，这些单个模型的视图页面可能具有优先于您站点的默认设置的附加视图脚本位置(将匹配所选主题).

Magento 在查找翻译文件和布局 XML 文件时将遵循相同的回退逻辑.

请注意，从 app/design/frontend/base/default/template/app/design/frontend/base/default/template/ 到您的本地主题，并根据您网站的主题自定义它们.然而，为了有一个升级兼容的站点，布局文件不应该从基础复制到你的本地主题.这样做并不遵循升级兼容做法.相反，您的主题的 XML 布局更新应包含在 app/design/frontend/PACKAGE_NAME/THEME_NAME/layout/local.xml 中.app/design/frontend/base/default/layout/* 中没有布局说明，无法删除/添加/更改，您有什么，使用正确的 XML 说明本地.xml.

From the following line in 2columns-right.phtml

<div class="col-main">
    <?php echo $this->getChildHtml('global_messages') ?>
    <?php echo $this->getChildHtml('content') ?>
</div>

I am not able to understand where the content in <?php echo $this->getChildHtml('content') ?> is coming from.

Which .phtml file is called to display the data by <?php echo $this->getChildHtml('content') ?>?

解决方案

If we're discussing the frontend of the website, the particular line you've asked about....

<?php echo $this->getChildHtml('content') ?>

is added to the Magento layout XML in app/design/frontend/base/default/layout/page.xml. In Magento version 1.8, you'll find it defined in lines 92-94.

<block type="core/text_list" name="content" as="content" translate="label">
    <label>Main Content Area</label>
</block>

By looking at the "type" attribute of this block tag, we can know what object class this section of the layout is. It comes from the "Core" module, and is of the block type Text List. The class name for this Mage_Core_Block_Text_List. (app/code/core/Mage/Core/Block/Text/List.php). Text Lists are simply block containers which purpose is to store additional child blocks inside them. You can add any number of child blocks to the text list and they will be rendered out either in the order they were added or the order they've been assigned.

So, to answer your question, there is no view script (.phtml file) that renders the contents of $this->getChildHtml('content'). The blocks which have been added to this block, may themselves have view scripts associated with them. To find out what view scripts those are, you'd have to find the layout XML which has added the block.

For example, if I had the following layout file added to the frontend of my website's theme:

<?xml version="1.0"?>
<layout>
    <default>
        <reference name="content">
            <block type="core/template" name="my_view_script" template="hello/world.phtml" />
        </reference>
    </default>
</layout>

The code above, would add the block with an object class of Mage_Core_Block_Template to the block with the name 'content' (which happens to be the one you asked about). Magento will then look for the view script in the following locations, in this order:

app/design/frontend/PACKAGE_NAME/THEME_NAME/template/hello/world.phtml
app/design/frontend/PACKAGE_NAME/default/template/hello/world.phtml
app/design/frontend/base/default/template/hello/world.phtml

First one that is found, is the one it will use. If no view script is found Magento will log an error in var/logs/system.log (default log file setting) stating that the view script was not found. No output from the block will occur.

Note that depending on your settings in System -> Configuration -> (General) Design, there may be additional package/theme locations Magento will look in. There are also other scenarios such as if the "Custom Theme" is field is changed for individual CMS Pages, Catalog Categories, or Catalog Products, these individual model's view page may have an additional view script location (that will match the selected theme) that takes precedence over your site's default settings.

Magento will follow this same fallback logic when looking for translation files as well as layout XML files.

Please note, that it is perfectly acceptable to copy individual view scripts (avoid copying entire directories, copy over only view scripts you actually intend to modify) from app/design/frontend/base/default/template/ to your local theme, and customize them for the purposes of your website's theme. However, in order to have an upgrade compatible site, layout files should not be copied from base to your local theme. Doing so, does not follow upgrade compatible practices. Instead, XML Layout updates for your theme should be contained in app/design/frontend/PACKAGE_NAME/THEME_NAME/layout/local.xml. There is no layout instructions from app/design/frontend/base/default/layout/*, that cannot be removed/added-to/changed, what-have-you, with the proper XML instructions in local.xml.

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