FME translations were originally based entirely on Mapping Files. Mapping files still exist under the surface but the interface has been replaced by Workbench's graphical interface.
Format mapping file directives are exposed as format parameters in Workbench. For each format reader and writer, there is a corresponding parameter settings dialog box.
We recommend that you use Workbench for all your transformation requirements; however, information on mapping files is included in this manual for technical reference purposes.
About Mapping Files
Mapping Files are ASCII text files that contain a series of rules that specify the FME readers, writers, and transformations.
A mapping file is a series of commands for FME to perform. Mapping files use functions and factories to transform the data. They also contain the definition and parameters for readers and writers. Before FME Workbench was designed and developed (approximately 2001), this was the only way to configure a translation process. You can still create and run mapping files through the FME Quick Translator, but this is suitable only for advanced users.
You can create a mapping file either by manually programming it or by using FME Workbench. In Workbench, there is an Export as .fme tool on the toolbar. The Workbench file format itself (.fmw file) is partially a mapping file with an XML header. When FME runs a workspace, it is converted into a mapping file.
Since mapping files are written in a plain ASCII format, you can use any text editor to edit them. To see what a mapping file looks like: select one or more transformers in Workbench, copy them, and then paste them in a text editor. The mapping file equivalent of these transformers will be pasted.
About Directives and Reader/Writer Keywords
Directives are processed by the reader or writer. In a mapping file environment, directives are prefixed by the current <ReaderKeyword> or <WriterKeyword>. By default, the keywords for formats are the format shortname (viewable in the Formats Gallery, or in the Format Quick Facts tables).