Added reverse filter support for v-for

[karevn]

An implementation for this issue: #1433

[yyx990803]

Nice one. Since this is v-for specific, maybe we can move the part into v-for as a method, and just call it in the watcher, e.g. forContext.applyReverseFilter(scope, value)

[karevn]

Agree. Btw, remember I offered to use <v-for> component instead of v-for directive? It would not only be a syntactic sugar, but would also allow to get rid of $forContext at all (it would all be about child - parent context relationships).

[yyx990803]

I think splitting this here makes the code harder to follow. It's ok that this check stay in the watcher.

[karevn]

It's more about responsibilities, IMO. Written this way, misc.js mixin is responsible for both forward and reverse filters, and abstracts forContext existence from the watcher.

Also, alias === expression does not look nice (because I easily bypassed this logic in my initial fiddle), so the logic will probably grow and I definitely don't want to put it to watcher (because it is not its responsibility) or for directive (to keep reverse filtering logic reusable just for a case). Any ideas?

[yyx990803]

When I saw scope._bubbleChanges it's a bit confusing, because this is a v-for-scope-only thing, but is attached to Vue's prototype, which imo is the wrong place. It only works because of the prototypal inheritance.

[yyx990803]

As for expression check - a reverse write should be applied as long as the expression starts with the alias. e.g. item.test and item[test] both should trigger reverse write. So you need a regular expression, e.g. new RegExp(alias + '\\b'). To be more efficient we might want to construct this regex right when we parse the alias in v-for.

[yyx990803]

Btw, if possible please re-submit this to the dev branch. Latest 1.0 work is now in the dev branch.

[ShahanurSharif]

this.reverse=(this.sortKey==sortKey)?!this.reverse:false; is not working in latest version for example

{{ people.name}} {{ people.age}}

sortBy: function(sortKey){
        this.reverse=(this.sortKey==sortKey)?!this.reverse:false;
        this.sortKey=sortKey;

    },
}

[karevn]

@MicroDreamIT I think you're missing the point of this PR. It's intended to allow to re-apply changes done to the array processed with two-way filters. Sorting and reverse order sorting are irrelevant to this.

[ShahanurSharif]

@karevn I am new in vuejs and javascript world, how can i make it happen?

[karevn]

@MicroDreamIT please ask this question at Vue chat: https://gitter.im/vuejs/vue