Type: class to support some kind of mapping or parse function

[jrmyio]

I came across an issue where my model has a "status" property that can be "phase1", "phase2" or "phase3" and my classes are equal but prepend "widget-". When I try to use the bindings to change the class of the view element there is no way to prepend, append or parse the class name.

As a work around I had to poison my models with class properties. In my opinion models should not contain any CSS information so i propose the following syntax to make my usage possible without modifying the models:

bindings: {
            'model.status' : {
                type: 'class'
                parse: function(status){
                        return "widget-" + class;
                }
            }
}

[legastero]

Ah, I've had to deal with this situation before a few times. Creating derived properties on the view was what I ended up with:

    derived: {
        widgetStatus: {
            deps: ['model.status'],
            fn: function () {
                return 'widget-' + this.model.status;
            }
        }
    },
    bindings: {
        widgetStatus: {
            type: 'class'
        }
    }

[kamilogorek]

+1 on this. Classes namespacing may come handy when working with really generic APIs.

[jrmyio]

Views can hold props/derived? I made a AmpersandJS/ampersandjs.com#81 on this undocumented feature.

However, I think the proposal still stands.

[chesles]

+1 on this -

Defining a derived property on the view is a decent workaround, but quite often there's something you want to do just to transform the value of the model's property before displaying it, whether it's prefixing a class, formatting a date or a number, etc. It's not ideal to have to define a bunch of formatted_[property] or prefixed_[property] properties that are just an extra layer between what is actually being rendered. It would be nice to define that function right there as part of the binding, as proposed here.

I think the option should be named something like format or transform instead of parse to make it clear what the function is meant to do: not necessarily parsing anything, but formatting or transforming the value for display.

[pgilad]

Closing this as a duplicate of #13 - It will be resolved there.