Allow shpext tag to take arguments to expand, format and project shape extents

[sdlime]

The shpext tag current currently outputs the bbox for a given query feature as a space delimited string. It is desirable to give users more control over the presentation of that string. We need to support a few simple attributes such as:

• expand: given in map units (pre-projection) or as a percentage (this is not a true buffer operation)
• format: define coordinate and point seperators (similar to shpxy tag)
• projection: see [shpxy ...] tag
• escaping: see [shpxy ...] tag

This is basically identical support to what exists to the shpxy tag. An unattributed [shpext] tag would work just as it does now.

Steve

[sdlime]

Committed a version of this in r7625 that allows for:

• formating (default is "minx miny maxx maxy")
• number precision control
• extent/bounds expansion
• escaping

Still todo's are projection and support for percentage expansion. I'll file separate bugs for those in the next release. Support is available for the following tags:

• mapext, rawext, refext, mapext_latlon and shpext

Eventually we can deprecate a number of tags including all the [..._esc] extent tags and all those used to expose individual parts of an extent (e.g. [shpext_minx]).

Examples:

[shpext precision=0 format="$minx,$miny,$maxx,$maxy"]

would output:

123456,123456,567890,567890

and:

[shpext precision=0 format="$minx,$miny,$maxx,$maxy" expand=1000]

would output:

122456,122456,568890,568890

Moving to a documentation enhancement now.

Steve

[jmckenna]

- updated the Template File Reference doc for mapext, rawext, refext, mapext_latlon and shpext changes.