Documenting RequestParam DTOs

[mustaphazorgati]

Because we have too many request parameter for some endpoints we decided to wrap them into dedicated DTO like so:

@GetMapping(path = "/url")
@Transactional(readOnly = true, rollbackFor = Exception.class)
public ResponseEntity<?> getListOfSomething(
  FilterParameter filterParameter,
  SortParameter sortParameter,
  PagingParameter pagingParameter) { 
    /*...*/
}

Unfortunately this way the code looks clean, but the request parameters which are contained within each DTO are not documented.

Is this currently not supported or are we doing something wrong?

[jmisur]

Thanks for the submition, let's discuss details on the PR.

[jmisur]

Hi @mustaphazorgati. I just looked into this again and realised what you are trying to achieve is actually a support for ModelAttribute without annotation. If I'm getting this right, from documentation of method arguments:

Any other argument

If a method argument is not matched to any of the earlier values in this table and it is a simple type (as determined by BeanUtils#isSimpleProperty, it is a resolved as a @RequestParam. Otherwise, it is resolved as a @ModelAttribute.

We already have a support for @ModelAttribute annotation via JacksonModelAttributeSnippet. See controller and test. This one could theoretically work without annotation if I look at the implementation logic.

So what I would propose you to do:

• Try using the model attribute configuration
• Try annotating your request DTOs with @ModelAttribute annotation

If none of this will work, or will work in a different than intended way, please share your results with us.

[mustaphazorgati]

Hey @jmisur,
thank you for your response. Indeed The JacksonModelAttributeSnippet was what we were looking for. Unfortunately that Snippet only resolves the ModelAttribute DTO. Since we have multiple ModelAttribute DTOs I extended that snippet to recognize multiple ModelAttributes. That change is backwards compatible and does not break anything. Based on this change we could further customize the Snippets for multiple Types. Furthermore I also expanded the JacksonRequestFieldSnippet in the same way.

[jmisur]

Are you able to check master on your project?