Write To
The number of JSON files that are written.
- Multiple Files (default) – Each feature type is written to its own JSON file. Each JSON file is named after the feature type.
- One File – Every feature type is written together in the same JSON file (which is named according to the File Name parameter).
File Name
Enter the name of the output JSON file. This parameter is optional and is only available when Write To is set to One File.
If this parameter is unused, then the JSON file is named after the folder to which it is being written.
Formatting Parameters
Formatting Type
The formatting of the output JSON file.
- Linear – The entire JSON document is output on one line. This option produces the smallest possible JSON files.
- Pretty Print – The JSON document will contain additional whitespace characters, making it much more human-readable.
Indent Size
This parameter controls the indentation style in the JSON document, and is enabled when Formatting Type is Pretty Print. The indentation style can use either tab characters, or a variable number of space characters.
Spatial
Coordinate System
Coordinate systems may be extracted from input feature data sources, may come predefined with FME, or may be user-defined. FME allows different output and input coordinate systems, and performs the required coordinate conversions when necessary.
If a coordinate system is specified in both the source format and the workspace, the coordinate system in the workspace is used. The coordinate system specified in the source format is not used, and a warning is logged. If a source coordinate system is not specified in the workspace and the format or system does not store coordinate system information, then the coordinate system is not set for the features that are read.
If a destination coordinate system is set and the feature has been tagged with a coordinate system, then a coordinate system conversion is performed to put the feature into the destination system. This happens right before the feature enters into the writer.
If the destination coordinate system was not set, then the features are written out in their original coordinate system.
If a destination coordinate system is set, but the source coordinate system was not specified in the workspace or stored in the source format, then no conversion is performed. The features are simply tagged with the output system name before being written to the output dataset.
For systems that know their coordinate system, the Coordinate System field will display Read from Source and FME will read the coordinate system from the source dataset. For most other input sources, the field will display Unknown (which simply means that FME will use default values). In most cases, the default value is all you'll need to perform the translation.
You can always choose to override the defaults and choose a new coordinate system. Select More Coordinate Systems from the drop-down menu to open the Coordinate System Gallery.
Changing a Reprojection
To perform a reprojection, FME typically uses the CS-MAP reprojection engine, which includes definitions for thousands of coordinate systems, with a large variety of projections, datums, ellipsoids, and units. However, GIS applications have slightly different algorithms for reprojecting data between different coordinate systems. To ensure that the data FME writes matches exactly to your existing data, you can use the reprojection engine from a different application.
To change the reprojection engine, Select Workspace Parameters > Spatial > Reprojection Engine. In the example shown, you can select Esri (but the selection here depends on your installed applications):
- The coordinate systems file coordsys.db in the FME installation folder contains the names and descriptions of all predefined coordinate systems.
- Some users may wish to use coordinate systems that do not ship with FME, and in those cases, FME also supports custom coordinate systems.
- Learn more about Working with Coordinate Systems in FME.
Quantization Value
Quantization removes information by reducing the precision of each coordinate. The writer will use the value of this parameter to limit the range of the coordinates.
The default value is 100000, which is relatively accurate for grids of size up to 10000 x 10000. A smaller quantization value can reduce the size of the output file when writing out a large number of coordinates, at the cost of the precision and accuracy of the coordinates. See more information: https://stackoverflow.com/questions/18900022/topojson-quantization-vs-simplification.
Orientation of Areas
Counterclockwise (default) – Area geometries will be converted to a counterclockwise orientation.
Clockwise – Area geometries will be converted to a clockwise orientation.
Reproject to WGS84
By default, the GeoJSON writer will reproject all features to the WGS84/EPSG:4326 coordinate system.
Setting this parameter to No will disable this automatic reprojection, and feature geometries will be written in the coordinate system they had when arriving at the writer.
Features with no coordinate system will be assumed to already be in the WGS84 coordinate system.
Write Bounding Box
Setting this parameter to No (the default) will disable writing the optional Bounding Box object.