Author: Mrunali Rane
Why to use Custom Mapping Files?
- It is very usual for a Mulesoft Developer to have a use case where he or she must execute various DWL Mappings depending on the conditions.
- In most cases the choice router comes as a solution.
- But what if there are more conditions and mappings in the future? The developer must update the code in such cases.
- We may fix this problem by using Dataweave mapping as Custom Modules.
Where to write DWL Mappings as Custom Modules?
- Create a subdirectory and file for your mapping module in the Studio project. Create a subfolder in src/main/resources named modules.
- Create a custom module file with a DWL mapping, such as Accounts.dwl or HR.dwl.
- Saving the module within src/main/resources makes it accessible for use in any DataWeave script within the Mule app in that project.
- Create your function in your mapping file, for example:
How to Import the Mappings as Custom Modules?
- To use the mapping file we need to import the module in the Transform Message component using Dataweave code. To get to the mapping body, a developer needs to use the function name.
- Following are the steps:
- Specify the import directive in the header.It’s either modules::HR or modules::Accounts in our case.
- Invoke the Mapping::main function. In our example it is HR::hrdep or Accounts::accdep. The function expects payload as an input to perform the mapping.
- Please refer to the below code snippet.
- The following output will be created because our variable value is “HR.”
