Make bindings extensible

[RickButler]

I realize that extending private methods is inadvisable, but I had overwritten the binding call in _initializeBindings for several projects prior #105.

Would there be opposition to storing ampersand-dom-bindings as an attribute of the view (I would be okay with it being private), instead scoped to the module as var bindings?

For example I have a copy of ampersand-dom-bindings with additional types defined in getBindingFunc. This would allow me to extend the base view with my custom implementation of ampersand-dom-bindings, instead of overwriting the private method _upsertBindings. It would also allow for easier use of different binding implementations, as long as they return a key-tree-store.

[cdaringe]

interesting. what sort of custom bindings have you made? would they be helpful to roll back into ampersand-dom-bindings instead?

[RickButler]

@cdaringe, they are a subset of the text/innerHtml binding types.

For example, instead of polluting my models with derived types to convert a prop to a specific date/monetary or other format, I use a binding types to achieve this globally.

I use custom bindings instead of custom dataTypes because I may use the original value in other derived properties, bindings, or computations.

I would like propose changes to ampersand-dom-bindings complimentary to this proposal.

[cdaringe]

instead of polluting my models with derived types to convert a prop to a specific date/monetary or other format, ...

I like that. It's a great idea.

I think we should definitely support the extensibility you need. While im not gung-ho against your original proposal, perhaps we could simply add hooks to dom-bindings to make it more composable? that way, there's only change required in one spot. i think it's a little clearer to extend dom-bindings too. the flow remains unchanged in &-view, and there's no logic to debug outside of dom-bindings. i think it'd be easier to reason about. what are your thoughts?

[RickButler]

@cdaringe it depends on how the changes to ampersand-dom-bindings are made, it may still require other changes to &-view.

Either allowing the new bindings to be passed in from the view, or making dom-bindings a class that can be extended instead of a function would both require changes to the view.

[cdaringe]

dom-bindings a class that can be extended instead of a function

just thinking out loud. i was thinking something similar to ^^. basically add .extend() method to dom-bindings. on app init, you extend to add your custom bindings. maybe im missing something, but I don't think that'd required an &-view update

[RickButler]

@cdaringe that would be treating dom-bindings as a singleton like ampersand-app? What if you overwrite one of the original bindings but don't want to use it in every view or you just don't want them available in every view? I'm fine with doing it that way, just thought I would bring up the possible objections.

[cdaringe]

yea, that'd be an issue. frankly, I personally wouldn't want to squash a dom-binding. i can see that really confusing the rest of the dev-team. i'd prefer instead to maybe namespace it? like myproduct/binding-name. again, i'm super on board with the need to make it extensible, and think you've got a great use case. i'm iffy on the requirement to convert what is otherwise a general utility function provider into utility provider instances. from my current thinking, i wouldn't ever think of creating an isolated lodash instance to get special utility functions. i'd definitely extend it (as peeps commonly do), but instancifying dom-bindings seems like convolution from my perspective. again, just an opinion :)

[orenmizr]

hi Richard. As a user of ampersand, I'm interested in your use case (perhaps i'll adopt that approach). you said: "For example, instead of polluting my models with derived types to convert a prop to a specific date/monetary or other format, I use a binding types to achieve this globally."

can you give me an example where that is preferred?

[RickButler]

I opened AmpersandJS/ampersand-dom-bindings#53 so that we can discuss changes specific to ampersand-dom-bindings there.

[RickButler]

@cdaringe, I would like to look at adding the ability to pass in bindings defined in the view, similar to ampersand-state dataTypes.

E.G. defined an attribute on your view called bindingTypes as a key -> function store, then call bindings with context, bindings, and bindingTypes.

[cdaringe]

@RickButler, if you want to modify it to do so, i'll support it so long as:

• it comes with test(s)
• it comes w/ a README update
• isn't too invasive

throw up a PR, and we can get it going. thanks for explaining all your stuff so clearly :)