Reader Directives
This section describes the directives that are recognized by the VPF reader. Each directive is prefixed by the current <ReaderKeyword>_ when placed in a mapping file. By default, the <ReaderKeyword> for the VPF reader is VPF.
DATASET
Required/Optional: Required
In database mode (VPF_DB), the value for this directive is the path to the DHT file. The folder where this file exists is the root folder of the VPF database. This folder directly and indirectly contains all the libraries, coverages, feature classes and related metadata for the database. A typical mapping file fragment that selects a VMap database from drive e: would be:
VPF_DATASET e:/vmaplv0/dht
In coverage mode (VPF), the value for this directive defines the coverage folder that the reader will read from. A typical mapping file fragment that selects a VMap database from drive ‘e:’ would be:
VPF_DATASET e:/vmaplv0/noamer/hydro
Workbench Parameter: Source Vector Product Format Database File(s)
READ_UPPER_CASE
Required/Optional: Optional
If set to YES, all the attributes are read in uppercase; otherwise, the attributes are read in lowercase.
TILES
Required/Optional
Optional
This optional specification is used to limit geometric features that are produced. Only feature class features that exist in the specified tiles will be output. If no value is specified, then all the tiles in the library will be used. If a tiled subset is specified for a nontiled library, then this specification is ignored.
The syntax for the TILES directive used in a database mode reader (VPF_DB) is:
<ReaderKeyword> _TILES \ <libName0>{ <tileId0>, <tileId1>,...}\ ... \ <libNameN>{ <tileId0>, <tileId1>,...}
Note: You must specify libName.
Example:
VPF_DB_TILES H1316010{30} A1316080{50, 30, 31, 32, 33, 34} VPF_DB_TILES EURNASIA{1-5}
An option to listing a sequence of tile IDs is to specify a range of tiles. The syntax for a tile range is:
<tileId0>-<tileIdN>
The following example, using a tile range, is semantically equivalent to the previous example:
VPF_DB _TILES H1316010{30} A1316080{50, 30-34}
Note: In Database Mode reader (VPF_DB), if no IDs or DEFs are specified then tiles specified will only apply to coverages that are tiled. If a coverage is not tiled, then all the features from that coverage will be returned.
The syntax for the TILES directive used in a Coverage Mode reader (VPF) is:
<ReaderKeyword> _TILES \ <tileId0>, <tileId1>,...<tileIdN>
Note that this syntax is different from the one in DB Mode as it does not require that tile IDs be contained within curly braces. An example that selects tiles 30, 31, 32, 33, 34 and 50 :
VPF _TILES 50,30-34
Workbench Parameter
Tile IDs
TILE_EXTENTS
Required/Optional
Optional
This option specifies the regional extents of the tiled subsection. Note that this directive is ignored if the data is not tiled.
<ReaderKeyword>_TILE_EXTENTS [xmin, ymin, xmax, ymax]
Workbench Parameter
Tile Extents
DEF
Required/Optional
Optional
This optional specification is used to limit the available feature classes that are read. A feature class definition specifies the name of the feature class and the library and coverage where the class is located. Feature attribute information is ignored by the reader. The syntax for a DEF line used in a database mode reader (VPF_DB) is:
<ReaderKeyword>_DEF <libName>\<coverageName>\<featClass>
The syntax for a DEF line used in a coverage mode reader (VPF) is:
<ReaderKeyword>_DEF <featClass>
Any additional declarations in the DEF line parameter are ignored by the reader.
Note: If both DEF lines and IDs are used to specify feature class, then the intersect of these sets determines the actual feature classes to read.
IDs
Required/Optional
Optional
This optional specification is used to limit the available feature classes that are read. If no IDs are specified, then all available feature classes are read. The syntax of the IDs directive in a database mode reader (VPF_DB) is:
<ReaderKeyword>_IDs <libName>\<coverageName>\<featClass> \ ...\...\... \ <libNameM>\<coverageNameN>\<featClassO>
The syntax for a DEF line used in a coverage mode reader (VPF) is:
<ReaderKeyword>_IDs <featClass1> \ ... \ <featClassN>
Note: If both DEF lines and IDs are used to specify feature class, then the intersect of these sets determines the actual feature classes to read.
FEAT_TYPE_SEP
Required/Optional: Optional
The value for this parameter is the character that is used in a feature’s feature type to separate the library and coverage names from the metadata table and feature class names. If this attribute is not specified, then the ‘\’ separator is used.
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