Feature Representation

In addition to the generic FME feature attributes that FME Workbench adds to all features (see About Feature Attributes), this format adds the format-specific attributes described in this topic.

Built-in Fields
Field Name	Description
gcm_x_value	Stores the x-coordinate for the feature. if you wish to use this field directly, you will need the map precision to determine the actual value stored. It is always better to interrogate the geometry of the feature directly if you want to find the x or y coordinates of the feature.
gcm_xp_value	Stores another x-coordinate. For a line, these would be the two end-points of the feature. As with the X field, this must be combined with the map precision to yield an accurate value.
gcm_y_value	Stores the y-coordinate, in the same way as the gcm_x_value field stores the x-coordinate
gcm_yp_value	Stores the y-coordinate. This is analogous to the gcm_xp_value field.
gcm_angle	Determines the angle of the object in tenths of a degree used for symbols and text features)
gcm_length	Gives the pre-computed length of the feature.
gcm_surface	Stores the precomputed area of the object along with the units used.
gcm_class_name	Stores the unmodified value for the name of the class
gcm_subclass_name	Stores the unmodified value for the name of the subclass
gcm_identifier	Stores the invariant identifier for the map object. It will be a unique value within a map
gcm_name	Stores the name of the map object. For text objects, this field stores the displayed text string

A user-defined field may be of any type specified in the DEF section.

As noted earlier, two features that are of the same type and subtype share all the same fields, and only their values for these fields and their geometries may differ.

It should be noted, however, that there is no requirement that a user-defined field be assigned to each feature. So, a given feature may fail to have a value for a given field. Within FME, we represent an attribute that is null by not setting such an attribute.

In some cases, it may be that a user-defined attribute will clash with a GeoConcept built-in field name. In such cases, the user-defined attribute is renamed until there is no such clash of names.

For example, if you define an attribute “Name”, this is likely to collide with the built-in “Name” attribute in GeoConcept. If you actually wish to modify the Name built-in field in the GeoConcept map, you may do so by using the format attribute gcm_name, and assigning it whatever value you wish.

In addition to these, there is a set of reader-only attributes relating to the appearance of the object in GeoConcept. FME has limited support for appearances. They are not available on the writer, and all objects will have the default appearance for their class/ subclass that the destination map provides.

Arrow Field Attributes

For map objects containing an arrow, the following attributes define its characteristics. All arrow attributes have integer values. The gcm_arrow_s_value is a reserved value for GeoConcept whose value may change based on GeoConcept.

Built-in Fields
Field Name	Description
gcm_arrow_s_value	Provides the “s” value for the arrow. This is a reserved attribute.
gcm_arrow_colour_red	Provides the “red” value for the arrrow.
gcm_arrow_colour_green	Provides the “green” value for the arrrow.
gcm_arrow_colour_blue	Provides the “blue” value for the arrrow.
gcm_arrow_angle	Provides the angle of the arrow’s head.
gcm_arrow_fill_percentage	Provides the percentage fill of the arrow.
gcm_arrow_length	Provides the arrow length.
gcm_arrow_thickness	Provides the arrow thickness.
gcm_arrow_flags	Provides the flags set on the arrow.
gcm_arrow_number_of_segments	Provides the number of segments that comprise the arrow.

Text Feature attributes

Text features in GeoConcept can have their appearance described in a number of ways. The following set of attributes specifies that appearance.

The attribute gcm_textAppearance.font specifies the name of the font (as a string). The font size is described by the attribute gcm_textAppearance.fontSize, and is restricted to an integer value. The strikeout, italic, underlined and framed properties of the text are given by the respective attributes below, and are Boolean values.

Built-in Fields
Field Name	Description
gcm_textAppearance.font	Provides the text feature’s font.
gcm_textAppearance.fontSize	Provides the text feature’s font size.
gcm_textAppearance.fontStyleStrikeOut	Specifies if the text feature is styled “strikeout”
gcm_textAppearance.fontStyleItalic	Specifies if the text feature is styled “italic”
gcm_textAppearance.fontStyleUnderlined	Specifies if the text feature is styled “underlined”
gcm_textAppearance.fontStyleFramed	Specifies if the text feature is styled “framed”

General Appearance Attributes

These attributes provide information on the appearance for each object. In each case, the values are integers which reflect an index into a table within the source GeoConcept map.

Built-in Fields
Field Name	Description
gcm_appearance_flag	Provides the flags on the appearance.
gcm_appearance_primary_ colour	Provides the primary color on the appearance.
gcm_appearance_secondary_ colour	Provides the secondary color on the appearance.
gcm_appearance_pattern	Provides the appearance pattern on the appearance.
gcm_appearance_primary_ width	Provides the primary width on the appearance.
gcm_appearance_icon	Provides the icon value for the appearance.
gcm_appearance_symbol	Provides the symbol value for the appearance
gcm_appearance_visibility	Provides the visibility of the appearance
gcm_appearance_properties	Provides the properties on the appearance.
gcm_appearance_kind	Provides the appearance kind.