Configure jslt to include keys for null or {} values instead of omitting the key

[Mohammadcore]

Currently keys with null or {} or [] value are omitted. Is there a way to configure this behavior or where in code can I patch this so I force it to include empty/null keys as well.

[larsga]

This is something I was thinking we'd have to make configurable at some point. How do you want to configure it? Would a JSLT expression as filter work?

[Mohammadcore]

Would it have the flexibility of having control over each key (to include or not if null). Or would it be a filter that applies to all keys i.e. include all null keys or exclude all null keys.

[larsga]

I would say a filter to apply to all keys. If you want to control which key is included or not included you can handle that in the transform itself.

[Mohammadcore]

let's say it's a filter to apply to all keys. Yet for a use case might be needed to have control per key rather than globally.

Example:

let doestExists = functions:find($arg1)
let doestExistsEither = functions:find($arg2)
{
  "foo" : $doestExists,
  "bar" : $doestExistsEither
}

There should be a means to achieve following results when needed. The global config doesn't cover case 1.

1

{
  "foo" : null,
}

2

{
  "foo" : null,
  "bar": null
}

3

{}

[larsga]

But you already have full control per key in the template. I don't think giving you that control in the filter actually helps you any. It just moves the challenge somewhere else, and complicates the system.

I think I made my mind up:

• filter applies to all values (of keys)
• filter can be specified in JSLT
• filter can also be specified in Java, if desired

[Mohammadcore]

Technically you are right.
In practice, template is sometimes not easy to change if it is part of another team work or ...

But what you have mentioned is also a great enhancement comparing to have no configuration option.
Thank you very much.

[larsga]

It's true that you can't necessarily change other people's templates, but you can use them as input to your own template. At which point we're back where we started: making the template do what you want is just as easy as doing it in the filter.

I'll make the change. This may require a deeper change in the JSLT API, due to poor initial design. But I'll solve that.

[larsga]

That commit implements the filters, fixing this issue. @Mohammadcore Would be great if you could test this out.