This is a dialog formatting template. It is meant for use on interactive dialog pages, and may involve interactions between wiki markup, HTML, and JavaScript. Please carefully test any edits before making them.
This is a subtemplate of {{dialog/button}}. Given the specification of a single dialog parameter for the button, it determines whether a literal value is provided for the parameter (that is, whether the spec contains a double-colon), and if so, extracts the name of the parameter for subsequent use. If no literal value is provided, the template returns the empty string. Uses {{evalx}}.
