Use Domains to Organize Custom Blocks
All custom blocks appear on the Blocks tab of the Block Menus in Wires. This menu has a set of built-in categories to help organize blocks and make it easier for users to find what they are interested in.
If you register macros used as custom blocks without a domain, the blocks are added to a category named Macros. This single category can quickly be overwhelmed with custom blocks.
Instead, it is a best practice to organize custom blocks into additional categories to help identify their purpose or scope. You define the category for a custom block by assigning a domain to the macro. In addition to organizing custom blocks, macro domains also ensure that macro names are unique.
For macros defined in a macro library, you assign the domain to the entire library of macros:
<macros xmlns="http://www.open-mashup.org/schemas/v1.0/EMML"
xmlns:presto="http://www.jackbe.com/v1.0/EMMLPrestoExtensions"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
schemaLocation="http://www.openmashup.org/schemas/v1.0/EMML/..
/schemas/EMMLPrestoSpec.xsd"
domain="myBlocks">
...
</macros>
For macros you define individually in the Mashup Editor, you assign the domain name when you save the macro.