Magento结构深入分析

安装Magento后默认目录结构：

•  .htaccess
•  .htaccess.sample
•  404 (directory)
•  app (directory)
•  cron.php
•  downloader (directory)
•  favicon.ico
•  index.php
•  index.php.sample
•  js (directory)
•  lib (directory)
•  LICENSE_AFL.txt
•  LICENSE.txt
•  media (directory)
•  pear
•  pkginfo (directory)
• report (directory)
• skin (directory)
• var (directory)

根目录中各文件职能说明

• .htaccess—This file controls mod_rewrite for fancy URLs and sets
  configuration server variables (such as memory limit) and PHP maximum
  execution time, so that Magento can run better.
• .htaccess.sample—Works as a backup for .htaccess, so that we know
  the default .htaccess file (if ever we edit it and need to backtrack).
• cron.php—The file that should be executed as a cron job every few
  minutes to ensure that Magento’s wide caching doesn’t affect our
  server’s performance.
• favicon.ico—Magento’s default favicon; it’s the small icon that appears
  in the toolbar of our browser.
• index.php—The main loader file for Magento and the file that
  initializes everything.
• index.php.sample—The base template for new index.php files, useful
  when we have edited the index.php file and need to backtrack.
• LICENSE_AFL.txt—It contains the Academic Free License that Magento
  is distributed under.
• LICENSE.txt—It contains the Open Software License that Magento is
  distributed under.
• pear—This controls all automatic updating via the downloader and SSH.
  This file is initialized and handles the updating of each individual module
  that makes up Magento.
• php.ini—A sample php.ini file for raw PHP server variables
  recommended when setting up Magento on our server. This should not be
  used as a complete replacement, but only as a guide to replace certain lines
  of the php.ini server file. It is useful when overriding these variables when
  .htaccess isn’t enabled on our server.

根目录中各目录职能说明

• 404—The default 404 template and skin storage folder for Magento.
• app—All code (modules), design (themes), configuration, and translation
  files are stored in this directory. This is the folder that we’ll be working
  in extensively, when developing a Magento powered website. Also
  contained in this folder are the template files for the default administration
  theme and installation.
• downloader—The web downloader for upgrading and installing Magento
  without the use of SSH .
• js—The core folder where all JavaScript code included with the installation
  of Magento is kept. We will find all pre-compiled libraries of JavaScript here.
• lib—All PHP libraries used to put together Magento. This is the core code
  of Magento that ties everything together. The Zend Framework is also stored
  within this directory.
• media—All media is stored here. Primarily for images out of the box, this
  is where all generated thumbnails and uploaded product images will be
  stored. It is also the container for importing images, when using the mass
  import/export tools.
• pkginfo—Short form of package information, this directory contains text
  files that largely operate as debug files to inform us about changes when
  modules are upgraded in any way.
• report—The skin folder for the reports that Magento outputs when any
  error occurs.
• skin—All assets for themes are stored within this directory. We typically
  find images, JavaScript files, CSS files, and Flash files relating to themes,
  in this directory. However, it can be used to store any assets associated
  with a theme. It also contains the skin files for the installation of skins and
  administration templates.
• var—Typically where we will find all cache and generated files for Magento.
  We can find the cache, sessions (if storing as files), data exports, database
  backups, and cached error reports in this folder.

模板系统结构

• /app/design/frontend/default/<template_name>/
  • layout/—For all the XML files declaring which module tied
    functions should be called to which template files
  • template/—For all the templates processing the output that
    is passed from functions called from layout/ and structured
    into the final output to the user.
• /skin/frontend/default/<template_name>/—For the containment
  of all assets relating to our template, images, CSS, Flash, and JavaScript.

结构板块（Structural Blocks），以三栏结构为例：

• header
• left
• content
• right
• footer

每个结构板块中又包含若干个内容板块（Content Blocks）,以右栏为例：

• mini cart
• recently viewed products
• newsletter subscription block
• poll

XML布局文件：结构板块通过请求调用XML布局文件来分配展现，所有页面都基于page.xml，一个典型的XML布局文件的结构如下：

<default>
	<reference name="header">
		<block type="page/html_header" name="header" as="header">
		<block type="page/template_links" name="top.links"
		as="topLinks"/>
		<block type="page/switch" name="store_language"
		as="store_language"
		template="page/switch/languages.phtml"/>
		<block type="core/text_list" name="top.menu" as="topMenu"/>
		</block>
	</reference>
</default>

相关标签的作用

•  <default>—The handler for the URL, in this case default will load no matter what other handler is being initialized
•  <reference>—The reference structure which calls the blocks in our theme
•  <block>—A content block which defines the type of block and the template which will process the block’s outgoing data in the system

此外，可以通过action来添加输入，如css

<block type="page/html_head" name="head" as="head">
	<action method="addCss">
		<stylesheet> css/menu.css </stylesheet>
	</action>
	<action method="addCss">
		<stylesheet> css/clears.css </stylesheet>
	</action>
	<action method="addItem">
		<type>js</type>
		<name>varien/iehover-fix.js</name>
		<params/>
		<if>lt IE 7</if>
	</action>
	<action method="addCss">
		<stylesheet>css/print.css</stylesheet>
		<params>media="print"</params>
	</action>
	<action method="addCss">
		<stylesheet> css/print.css </stylesheet>
		<params> media="print" </params>
	</action>
</block>

Magento官方有关布局的相关解释详见：http://www.magentocommerce.com/design_guide/

articles/intro-to-layouts

Magento中的优先级：新主题中调用文件如logo.gif将优先从当前主题相关目录中读取，若该文件不存在，则调用默认主题中的相对应文件。

Magento用户指南及电商小贴士士：http://www.magentocommerce.com/resources/magento-user-guide

Magento中的模块

Magento将所有的功能划分成一个个小模块，所有的模块都放在/app/code/目录中，按类型将模块划分为如下三类：

• community—For community-distributed extensions, usually those that we
  have installed through Magento Connect or have downloaded from a source,
  other than our own. Anything installed through Magento Connect will be
  installed here automatically.
• core—Reserved for core Magento modules, so that we cannot directly
  overwrite or interfere with them. We keep our modules out of core to avoid
  any conflict with the core modules or any future updates. Anything from a
  Magento upgrade or any new Magento modules will go into this directory.
• Local—This is where we should be placing our modules when they are
  either under local development or are not distributed among the community.
  It’s best to keep anything that we develop in this directory, so as to not
  interfere with the core or community modules. Nothing will be automatically
  installed here, unless we have physically uploaded it.

模块的基本目录结构

• Block/
• controllers/
• etc/
• Model/
  • Mysql4/
    • Book/
• sql/
  • book_setup/

关于备份

在开发新功能或进行其它修改时都建议对于现有文件进行备份，最简单也最万无一失的办法就是手动将所有文件下载到本地。另外就是通过SSH来进行备份，使用的相关指令示例如下：

tar cf magento_archive.tar * （将所有文件压缩到magento_archive.zip）

tar -xvf yourfilename.tar （解压缩相关备份文件）

mv magento_archive.zip /path/to/new/destination/ （移动备份文件到指定目录）

cp –R * /path/to/new/destination/ （复制所有文件到指定目录）

对于数据库的备份可以通过后台System>Tools>Backups中的Database Backup按钮来进行备份，备份文件将保存在/var/backups/下，也可以通过phpMyAdmin中的export功能来进行输出备份。