TXMLConfig-PathSyntax topic

In unit Laz2_XMLCfg

TXMLConfig Path Syntax.

Declaration

pascal

TXMLConfig-PathSyntax

Description

Path specifiers in TXMLConfig are used to get or set a value in the XML configuration file. Its syntax describes the hierarchy of elements and attributes needed to access a value in the XML document. It consists of a relative path to a DOM node and an attribute name where the value is stored.

The path specifier should NOT include a root node (or document element name); that is assumed to be a DOM node with the name "CONFIG". Use of the root node in the specifier is invalid in TXMLConfig.

Element and attributes names in the hierarchy are separated by the '/' (Forward Slash) character. The final identifier in the path specifier is the attribute name where a value is stored in the XML document.

Lists or arrays of elements can be read /written using a path specifier that includes notation which indicates the ordinal position of the element. For example:

ACfg.SetValue('list/items/item[0]/name', 'itemA');
ACfg.SetValue('list/items/item[0]/value', 'valueA');
ACfg.SetValue('list/items/item[1]/name', 'itemB');
ACfg.SetValue('list/items/item[1]/value', 'valueB');
ACfg.SetValue('list/items/item[2]/name', 'itemC');
ACfg.SetValue('list/items/item[2]/value', 'valueC');

Results in the following XML content:

<list>
  <items>
    <item name="itemA" value="valueA"/>
    <item name="itemB" value="valueB"/>
    <item name="itemC" value="valueC"/>
  </items>
</list>

There is no overloaded variant of the SetValue method which handles writing a TRect data type in the current implementation. You must write the Top, Left, Right, and Bottom coordinates as separate calls to SetValue using the desired path.

Contrary to suggestions in source code comments, the syntax used for path specifiers in TXMLConfig is not fully XPath-compatible.

TXMLConfig-PathSyntax topic

Declaration

Description

See also