GetMappableFields()

Summary

Creates a list of the fields that are mappable to a layer.

 

Syntax

fields_array = GetMappableFields(string layer_name, string field_type)

 

Argument	Contents
layer_name	The input layer; or null for the current layer.
field_type	The string "All" to return a list of all fields in the view; the string "String" to return a list of string-typed fields, the string "Numeric" to return a list of all integer- and real-typed fields or the string "ABBA" to return a list of "dual fields.

 

Returns

An array of two (2) elements:

 

Element	Type	Contents
1	Array	An array of mappable field names (strings).
2	Array	An array of field specs (strings).

 

Notes

• A mappable field is any field that is on the base layer view or on a joined view that is mappable to the layer.

• The field_type value of ABBA returns a list of "dual fields," i.e. fields which have the same type and matching name, except one has "ab" replaced with "ba". For example, fields "AB_Flow" and "BA_Flow" which are candidate fields for a dual sized theme on a line layer. With this field type, the function returns an even number of field names, with matching AB/BA fields in pairs.

• The arrays returned by GetMappableFields() do not contain repeated fields -- in particular, a field on the layer base view has a counterpart in any mappable joined view. GetMappableFields() returns only the field on the base view, and not its counterpart in the joined view.

• Typically, the array of mappable field names is used to present to the user, e.g., in a popdown list. The array of field specs is then used in calling other functions, e.g., GetFieldWidth(), which require a field spec instead of just a field name.

• GetMappableFields() returns null if the layer does not exist, if layer_name is null and there is no current layer, if the layer has no mappable fields of the specified type, or if the field_type is not recognized.

Example

tmp = GetMappableFields("U.S. States", "All")

fld_names = tmp[1]

fld_specs = tmp[2]

 

Error Codes

Error Type	Meaning
Error	The input layer is not geographic, e.g., it is an image layer.

 

See Also

Function	Summary
GetField()	Returns the view, field name, and field spec for a field
GetFieldFullSpec()	Returns a full field spec for a field name
GetFields()	Gets a list of the fields in a view
GetMappableFieldIndices()	Determines the positions of mappable fields in the arrays returned by GetMappableFields()