When you add a repository item using the <add-item> tag, you can use the tag attribute in place of the id attribute. If you use a tag attribute, the SQL repository chooses a unique repository ID for the item using the IdGenerator and associates that tag with that ID. You can then refer to that particular tag name within that .XML file, using a tag attribute. In the alternative, you can refer to the tag using this special syntax:
$tag:<name>$
The $tag:<name>$ syntax can be used only in:
the
valueattribute or body of a<set-value>tagthe
queryattribute or the body of a<query-items>tag
The template parser substitutes the ID of the item you created using that tag.
For example, suppose you want to add an item, one of whose properties is another repository item. Let’s say we are adding a book item, and the book item has a author property, which is itself a repository item. If you don’t want to supply the repository ID for the author repository item, you can use a tag attribute placeholder like this:
<add-item item-descriptor="author" tag="AUTHORID_TAG">
<set-property name="authorName" value="Arthur Ransome"/>
...
</add-item>
<add-item item-descriptor="book">
<set-property name="title" value="Swallows & Amazons"/>
<set-property name="author" value="$tag:AUTHORID_TAG$"/>
</add-item>
