When an activity execution requires the system to produce and send HTML to a user's browser, the system assembles and analyzes the source HTML using stream processing.

During this process, the system interprets JSP tags, retrieves clipboard values, finds and inserts the HTML from <pega:include > tags, and so on. Similar processing occurs for source HTML, using correspondence rules, correspondence fragments, and the clipboard contents. For services and connectors that reference XML Stream rules, the processing is similar.

As it processes the XML or HTML, at each position in the source HTML text, the system identifies one property as the active property.

Keywords and shorthand notations in source HTML are defined for the current active property. Using these keywords can simplify your source HTML and enrich the user experience with the resulting form:

• The keyword $this-message used with the reference tag causes the system to include the text of any message associated with the active property.
• The keyword $this-value identifies the value of the active property.

As your create source HTML, you can cause a property to become the active property using the NAME attribute, or the withReference JSP tag. When the scope of the tag ends, the previous active property is reinstated as the active property.

	source HTML, stream processing
	JSP Tags — withReference How to reference properties indirectly in JSP tags

Definitions — A