Feature request: Allow chained/fluent setters

[djarnis73]

Hi

I tend to use chained setters quite a lot and was wondering if it would be difficult to allow them, either by default or through configuration.

I wouldn't mind cooking up a PR if i think it would be a good idea (and if it is not too complex).

I did do a search through the issues to see if this is a duplicate, but did not find anything.

Best regards Jens

[schuettec]

Thank for your idea.
Can you give me a short example of what you want to do?
Just to get the use-case right.

My first guess would be, that the complexity for this feature might be high because if you want to chain setters, you have to have a valid instance of the source object available to invoke the setter on. The source object is generated later than the field-by-field mappings and currently there is no order defined on mappings.

[djarnis73]

By chained setters I mean setter that return this like:

class B {
  int i;

  B setI(int i) {
    this.i = i;
    return this;
  }
}

So my proposal is to relax the pure java beans requirement for setters (either globally or it could be a mapper configuration).

[schuettec]

Ah okay, so if your idea is to relax the validation of set-methods to support chained setters I would welcome a PR :)

Sounds very reasonable to support this.

[djarnis73]

I did a bit of research and debugging and I don't think there is a simple way to achieve this, since the bean introspection does not allow for chained/fluent setters.

It used to back in java 1.6.

So to implement this, we will either have to use a different introspection engine (extra external dependency), commons-beantutils seems to have one or write our own.

I will dig a bit deeper into this. One option could also be to generate two artifacts remap & remap-fluent where the -fluent has the extra dependency. But that would be at the cost of extra complexity in both code and build setup.

[djarnis73]

I have made a proof of concept commit here: djarnis73@bcd99c8 please have a look and let me know if you like it.

[schuettec]

Hi, very cool that you managed to do it!
That does not look that complicated. Good idea!

I would like to integrate your PR. I would check backwards compatibility with our code base an then we go for a release :)

[schuettec]

Ah! One more thing. ReMap has an API for testing. Can you verify with a test, that the Assert API works well with your extension?

[djarnis73]

How time flies, looks like I got distracted and never followed up on this. Are you still interested in getting this in? Then I will brush if off and submit a PR.

[schuettec]

Hey it's been a while :) I think it's a nice idea to support fluent setters. As you mentioned above, keep in mind, that you need another bean introspection service. Feel free to build a PR. Then we can figure out how to integrate this into remap :)