Visual attributes of map elements are mostly defined by styles. There are several types of styles (point marker styles, line styles and KML item styles); the applicable type is determined by the context, such as points layers use point marker styles, lines layers use line styles, and so on. Usually a style may be specified as a data driven expression (so that the actual style depends on run time data), with a fallback style used by default. How style expressions are specified and evaluated is described next.
The Map custom field contains 3 style collections:
These styles are available to all layers defined on the Map, and also to other Map fields in the current report. The styles in each collection are addressable either by index or - preferably - by name (using the Name property). When a style expression evaluates to a string, that string is used to search for a matching style, first in the current map and if that fails, in all other maps on the current report (only matching type styles are searched; for example, only MarkerStyles collections are searched for a point marker style, and so on).
