Double-Click-to-Copy <featurecaption> variable reference

[prushforth]

Background

The existing MapML extension allows the text entry of variable references into a text box that represents a string template, which is a bit like providing a user interface to enter program source code. The “legal” values of feature attributes or band names are presented in a list box adjacent to the text entry input, but this list serves as a reference only; it is not live or copyable. It is desired to make the process of obtaining legal attribute or band names for use in the string template less error prone and simpler.

Requirement

Improve the selection of attributes or band names for use in the mapping, by allowing the user to double-click or drag an attribute or band name from the select list into the string template as a pre-formatted property placeholder i.e. it appears at the end of the string in the text box below the attribute list, with the attribute or band name correctly formatted as a property placeholder “${attribute-or-band-name}”. Currently users must type out property placeholders themselves, which can easily lead to errors at runtime due to typos.