Unable to map snake_case JSON to Play Form with camelCase fields (Java)

[amvanbaren]

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Helpful things

Fixes

Fixes #11171

Purpose

What does this PR do?

• It maps the form data from a generic JsonNode to the form's backing type. After mapping, the data is converted back to a generic JsonNode. This time annotations are ignored.

• When the errorsAsJson method is called, it maps internal form field names (authorName) back to the corresponding JSON data field names (author_name).

• It fixes testLangErrorsAsJson() in HttpFormsTest by changing foo to amount. This was needed because the Money form doesn't have a field called foo.

• It fixes the fail with exception when the json payload is bigger than default maxBufferSize test scenario in DynamicFormSpec. A TextNode can't be mapped to a DynamicForm.Dynamic while a JsonObject can.

Background Context

Why did you take this approach?

The form data is converted to the form's backing type, so that Jackson naming annotations like @JsonNaming, @JsonProperty, @JsonSetter are applied to the form fields (e.g. from author_name to authorName). When mapping back, annotations are ignored to preserve the field names obtained from the previous mapping step (authorName stays authorName).

I needed to fix the tests, because JSON form binding has become stricter due to the mapping from generic JsonNode to the form's backing type.

References

Are there any relevant issues / PRs / mailing lists discussions?

[mkurz]

You need to run sbt formatCode to pass code style validation. Thanks!

Let's see if we can push this for 2.9.1 / 3.0.1.

[amvanbaren]

@mkurz I've formatted the code.

[mkurz]

@Mergifyio rebase

[mergify]

rebase

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