For data that has feature codes, but no feature description, there is additional metadata support, called Pass-Through Keys. The keys map column values to descriptive text used in the legend.
Table metadata contains pass-through text for legends if the following criteria are met:
- The metadata label expression is a simple column reference.
- A pass-through prefix key exists in the metadata that is the result of appending the column reference to the top-level "\legend" key.
- For example, given the following legend label expression key:
"\legend\label" = "CFCC"The following pass-through prefix key must also exist in metadata:
"\legend\CFCC"The prefix key may exist as a separate line in metadata:
"\legend\CFCC" = ""If the above two criteria are met, then the legend creation code looks for legend text in additional 'pass-through' metadata keys that are the result of appending evaluated label expressions to the prefix key. The values for each key replace the original expression value:
"\legend\CFCC\F32" = "Church" "\legend\CFCC\F34" = "Hospital" "\legend\CFCC\value_n" = "legend text used in place of CFCC value_n"This results in a legend with the descriptive text "Church", "Hospital"' etc., rather than "F32", or "F34".
See Also:
Metadata Pass-through Key Limitations
Once a Legend Frame that uses pass-through metadata keys for text is created, changes to the pass-through key values do not display in a Legend Refresh. They will display the next time the Legend Frame is recreated.