A Custom Format is an FME Workspace that can be used to preprocess data as if it were a data format on its own. Once created, it will show up in the input formats list. From then on, it can be used in any FME component as a separate format, including application extensions.
A Custom Format can only be an input format. When you create a Custom Format, you can, in effect, define your readers, your workflow, and the format's schema, and you can use it like a standard Source Format. This is useful if you consistently use the same information in a translation, and when you consistently perform the same processing on datasets. After you create and save the format, it will be selectable from the Formats Gallery.
There are two ways to start:
For more information and examples, see the FMEpedia article What is a Custom Format?
Open an existing workspace and select File > Export as Custom Format. You will be prompted to enter a name and description. A new Workbench window will open, and the custom format information will appear in the title bar.
To initiate the Custom Format wizard, select Tools > Browse Readers and Writers, and click the New button in the "Custom Formats" area at the bottom of the Gallery window.
The Custom Format wizard will guide you through the following steps:
Select the Source Format
Select the format of your source data. You can also click the Browse button to choose from the Reader and Writer Gallery.
Locate Source Data
Type the location of your input data. You can also browse for files or add multiple datasets. If the source format has specific default parameters that you want to change, you can edit them here by clicking the Parameters button. For help with Parameters, click the Help button in the parameter box.
Expose Parameters
The parameters listed here will depend on your source data, and the ones you select will determine which parameters will be shown when you use the format in a translation.
Name the Custom Format
Enter a short name and a description for the new format. When the format is saved to the Reader and Writer Gallery, the short name appears in the Short Name column, and the description appears in the Name column.
Note that you can use only ASCII characters in Short Names.
Create the Custom Format
Click Finish. Another instance of Workbench will start, displaying the custom format's feature types on the canvas. The Workbench title bar displays the default filename and file location. Like a regular workspace, you can do the following:
The only visible difference between a Custom Format and a Workspace is that there is no destination dataset. You can, however, add destination feature type definitions, which become the source schema for the custom format.
Save the Format
Select File > Save. The custom format will be added to the Reader and Writer Gallery. All custom formats in the gallery are preceded by a custom format icon, to distinguish them from standard FME-supported formats:
FME will automatically assign a default .fds file extension. The new
format will be stored, by default, in My Documents\FME\Formats.
From the Reader and Writer Gallery, choose the format, then click the Custom Formats > Edit button.
From the Reader and Writer Gallery, choose the format, then click the Custom Formats > Delete button.