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This is documentation for Caché & Ensemble. See the InterSystems IRIS version of this content.

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XData Blocks

Describes the structure of an XData block.


An XData block is a named unit of data that you include in a class definition, typically for use by a method in the class. Most frequently, it is a well-formed XML document, but it could consist of other forms of data, such as JSON.


An XData block has the following structure:

/// description XData name [ keyword_list ]  { data }


  • description (optional) is intended for display in the Class Reference. The description is blank by default. See “Creating Class Documentation” in Using Caché Objects.

  • name (required) is the name of the XData block. This must be a valid class member name, and must not conflict with any other class member names.

  • data (optional) contains the payload of the XData block. If XML, it must be a well-formed document (with a single root element), without the XML declaration at its start.

  • keyword_list (optional) is a comma-separated list of keywords that further define the XData block.

    See the section “XData Keywords.”

    If this list is omitted, also omit the square brackets.


XData Contents [ XMLNamespace="" ]
  <page xmlns="" title="HelpDesk">
    <html id="title">My Title</html>
      <pane paneName="menuPane"/>
      <spacer width="20"/>
      <vgroup width="100%" valign="top">
        <pane paneName="tablePane"/>
        <spacer height="20"/>
        <pane paneName="detailPane"/>

See Also