Factory versus new construction

[kitsonk]

As we were doing the proposal, it was discussed about doing a full factory implementation or following the constructor function pattern and utilise new for instantiation. I got involved in a side conversation at the request of one of the community and @ericelliott took some time to provide some feedback on why new is limiting and a challenge.

I think it is worth considering adopting a factory function as it does give a level of flexibility to the consumer and actually aligns to some of the patterns we were trying to promote anyways.

[kitsonk]

The one substantive argument for factories over new is that you do not have to actually create a new instance in the factory. Currently there is no such functionality in the compose proposal to do things like "pooling", but standardising instantiation on new would preclude that pattern in the future.

[maier49]

I think that in addition to the point about pooling you bring up, there are also some other benefits to using a factory(e.g. being able to bind whatever context you want to a factory function in case you don't want 'this' to reference the new object, and the fact that with new, if somebody is using your library you now can't move to a factory without breaking their code), but I think the most salient reason to use factories is that other than the potential lack of familiarity there's really no downside.

[ericelliott]

👍

[kitsonk]

@maier49 I think you summed it up...

• new instantiation
  • Benefits - perceived familiarity
  • Disadvantages - If a end user returns a value from a constructor function, it causes wastage which requires cleanup.
• factories
  • Benefits - pooling, object reuse, more familiar (DOM instantiation is a factory), instance binding, returning Proxies, etc...
  • Disadvantages - none

I will keep this open for a little bit longer, just in case anyone else wants their 2¢.

[kitsonk]

Discussion seems complete, so closing.