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XML Load Sequence
For developers, it is important to understand that blocks and layout updates must be loaded in the correct order, in keeping with the rules of precedence and load sequenceThe order in which scripts are loaded into memory. To work correctly, some scripts must be loaded before others. which determine how the page is rendered. Magento supports the following page layoutThe visual and structural composition of a page. scenarios:
Scenario 1: Default Layout
The default layout consists of the visual elements that are visible from every page of the store. Whether it is a menu item, or a shopping cartA grouping of products that the customer wishes to purchase at the end of their shopping session. block, each item has a handleIn programming, a name used to reference an object. in the default section of the layout definition.
Scenario 2: Changes to Specific Pages
The second case allows you to create a different layout for a specific page. The XMLExtensible Markup Language: A markup format derived from SGML that it used to format information for publication and distribution. layout for specific pages is constructed in the same sequence that Magento loads modules, and is determined by the system configuration.
In addition to the instructions in the layout updateA specific set of XML instructions that determines how the page is constructed. files which are specific to each module, you can make a custom layout update that applies to a special case in the backend, and is merged each time the special case occurs.