SEF Components

A SEF component is the foundation for many of the SEF features. In order to make SEF reference features or other regular features, one must fully comprehend the structure of the SEF components.

Each SEF component has a name and a type in addition to its regular attributes and its geometry attributes.

• Regular attributes are those attributes which are not related to coordinates, and are stored as attributes on the FME feature.
• Geometry attributes are coordinate-specific attributes, and are stored as coordinates in the component’s FME geometry.

Since there can be more than one component in a feature, each component’s attributes are prefixed by the keyword sef_component{<number>}. In this manner,

sef_component{0}.sef_lbl label0	\
sef_component{0}.sef_type sef_arc \
sef_component{0}.sef_usrAttribute material \
sef_component{0}.sef_prim_axis 10 \
sef_component{1}.sef_lbl label1 \
sef_component{1}.sef_type type1

where <number> is an integer that starts from 0.

If only one graphical component exists in any SEF Feature, the prefix sef_component{} can be omitted. For example, if we have a feature with a nongraphic component and a two-point line, then the sef_component{} list is optional. The SEF writer will write out all the user-defined attributes of the feature in a nongraphic component section preceding the graphical component section. However, if there is a preferred order in which the components are arranged, the user must do so via the sef_component{} mechanism.

The attributes below can be attached to all component types:

Keyword Suffix	Value	Required/Optional
sef_type	A text string specifying a supported SEF type. Range: sef_arc | sef_cell | sef_shape | sef_line | sef_curve | sef_symbol | sef_text | sef_fixed_text_node | sef_display_text_node | sef_complement_text_node | sef_repeat_text_node | sef_nongraphic Default: No default	Required
sef_lbl	A text string with a max of 31 characters specifying the label of the component. This defaults to an empty string.	Optional
sef_out_of_scope	Used this flag only if the component continues beyond the area defined by the index shapes in a SEF file. Range:begin | end Default: No default	Optional
sef_level	The level on which the component is located. Range: An integer from 1 to 63 Default: No Default	Optional
sef_style	The style of the component. Range: An integer from 0 to 7 Default: No Default	Optional
sef_color	The color of the component represented by an integer. Range: An integer from 0 to 255 Default: No Default	Optional
sef_weight	The thickness of the component. Range: An integer from 0..31 Default: No Default	Optional
<user defined>	This is a user-defined text string.	Optional

Each component may have additional attributes, depending on the sef_type of the component.