Reader Directives

The directive processed by the TIGER/Line reader are listed below. The suffix shown is prefixed by the current <ReaderKeyword> in a mapping file. By default, the <ReaderKeyword> for the TIGER/Line reader is TIGER.

DATASET

The name of a folder containing one or more TIGER/Line county file sets, or a single TIGER/Line file.

The filenames should all start with TGR, and the extensions should not be altered from the distributed form.

TIGER_DATASET D:\DATA\26_MI

Required/Optional

Required

Workbench Parameter

Source U.S. Census Bureau TIGER/Line File(s)

IDs

This optional specification is used to limit the available and defined TIGER/Line files read.

If IDs are not specified, then all available files are read. The syntax of the IDs directive is:

ReaderKeyword>_IDs	<baseName1>\
	<baseName2> ...	\
	<baseNameN>

The example below selects only the TGR26001.* county file set.

TIGER_IDs TGR26001

Required/Optional

Optional

LFIELD_AS_STRING

This optional directive determines whether or not to treat left-justified numeric fields as strings (which will preserve the leading zeros).

If the directive value is “yes”, the attribute values like “09” will be read as “09”. If the directive value is “no”, “09” will be read as “9”.

Note: This directive value can only be set during mapping file generation.

Mapping File Syntax

This example shows how to set the directive during mapping file generation from the command prompt.

> fme GENERATE TIGER NULL <sourceDataset> <outputMappingFile> --Source_LFIELD_AS_STRING no 

Required/Optional

Optional

SEARCH_ENVELOPE

Using the minimum and maximum x and y parameters, define a bounding box that will be used to filter the input features. Only features that interact with the bounding box are returned.

If all four coordinates of the search envelope are specified as 0, the search envelope will be disabled.

Mapping File Syntax

<ReaderKeyword>_SEARCH_ENVELOPE <minX> <minY> <maxX> <maxY>

Note: If all four coordinates of the search envelope are specified as zero, the search envelope will be disabled.

Required/Optional

Optional

Workbench Parameter

Minimum X, Minimum Y, Maximum X, Maximum Y

SEARCH_ENVELOPE_COORDINATE_SYSTEM

This directive specifies the coordinate system of the search envelope if it is different than the coordinate system of the data.

The COORDINATE_SYSTEM directive, which specifies the coordinate system associated with the data to be read, must always be set if the SEARCH_ENVELOPE_COORDINATE_SYSTEM directive is set.

If this directive is set, the minimum and maximum points of the search envelope are reprojected from the SEARCH_ENVELOPE_COORDINATE_SYSTEM to the reader COORDINATE_SYSTEM prior to applying the envelope.

Required/Optional

Optional

Mapping File Syntax

<ReaderKeyword>_SEARCH_ENVELOPE_COORDINATE_SYSTEM <coordinate system>

Workbench Parameter

Search Envelope Coordinate System

CLIP_TO_ENVELOPE

This directive specifies whether or not FME should clip features to the envelope specified in the SEARCH_ENVELOPE directive.

Values

YES | NO (default)

Mapping File Syntax

<ReaderKeyword>_CLIP_TO_ENVELOPE [yes | no]

Workbench Parameter

Clip To Envelope

EXPOSED_ATTRS

This directive allows the selection of format attributes to be explicitly added to the reader feature type.

This is similar to exposing format attributes on a reader feature type once it has been generated; however, it is even more powerful because it enables schema-driven applications other than Workbench to access and leverage these attributes as if they were explicitly on the schema as user attributes.

The result of picking a list of attributes is a comma-separated list of attribute names and types that will be added to the schema features. Currently all reader feature types will receive the same set of additional schema attributes for a given instance of the reader.

Required/Optional

Optional

Mapping File Syntax

Not applicable.

While it is possible for FME Objects applications to invoke this directive, the required format is not documented.

This directive is intended for use in our GUI applications (for example, Workbench) only.

Workbench Parameter

Additional Attributes to Expose