Backbone relational events not firing?

问题

class TheModel extends Backbone.RelationalModel
    relations:[
        type: Backbone.HasMany
        key: 'subModels'
        relatedModel: SubModel
        collectionType: SubModels
        reverseRelation:
            key: 'TheModel'
    ]

themodel = new the TheModel({subModels:[{#stuff},{#stuff},{#stuff}]})

I have createModels on so themodel.get('subModels') returns a collection of models.

Now if I pass changed subModel data into mymodel

themodel.set({subModels:[{changedstuff},{stuff},{stuff}]})

Shouldn't themodel throw a change event? It doesn't for me.

More so if I pass identical data into mymodel

themodel.set({subModels:[{samestuff},{samestuff},{samestuff}]})

themodel.attributes.subModels throws add and update events, even though nothing is new.

I'm not sure why these issues are happening, any help would be great, thanks!!!!

回答1:

If you reset a whole relation like that by setting a new collection, Backbone-relational will (at the moment) just replace the whole collection, instead of checking for differences. So it'll fire a remove event for all current subModels, then fire add events for each new one.

I do get change events though, with the following code (it would help if posted code contains a complete example though ;)

var SubModel = Backbone.RelationalModel.extend({});

var TheModel = Backbone.RelationalModel.extend({
    relations: [{
        type: Backbone.HasMany,
        key: 'subModels',
        relatedModel: SubModel,
        reverseRelation: {
            key: 'TheModel'
        }
    }]
});

themodel = new TheModel({subModels: [{ id: 5 },{id: 7},{id: 8}]})

themodel.bind( 'change', function() {
        console.debug( 'change; args=%o', arguments );
    });
themodel.bind( 'change:subModels', function() {
        console.debug( 'change:subModels; args=%o', arguments );
    });
themodel.bind( 'update:subModels', function() {
        console.debug( 'update:subModels; args=%o', arguments );
    });
themodel.bind( 'add:subModels', function() {
        console.debug( 'add:subModels; args=%o', arguments );
    });
themodel.bind( 'remove:subModels', function() {
        console.debug( 'remove:subModels; args=%o', arguments );
    }); 


console.debug( 'set new subModels' );
themodel.set( {subModels: [{ id: 5 },{id: 7},{id: 9}] } )

This yields the following output:

set new subModels
change:subModels; args=[Object { _queue={...}, attributes={...}, _escapedAttributes={...}, more...}, [Object { id=5}, Object { id=7}, Object { id=9}], Object {}]
change; args=[Object { _queue={...}, attributes={...}, _escapedAttributes={...}, more...}, undefined]
remove:subModels; args=[Object { _queue={...}, attributes={...}, _escapedAttributes={...}, more...}, Object { length=3, models=[3], _byId={...}, more...}, Object { _related={...}}]
remove:subModels; args=[Object { _queue={...}, attributes={...}, _escapedAttributes={...}, more...}, Object { length=3, models=[3], _byId={...}, more...}, Object { _related={...}}]
remove:subModels; args=[Object { _queue={...}, attributes={...}, _escapedAttributes={...}, more...}, Object { length=3, models=[3], _byId={...}, more...}, Object { _related={...}}]
add:subModels; args=[Object { _queue={...}, attributes={...}, _escapedAttributes={...}, more...}, Object { length=3, models=[3], _byId={...}, more...}, Object {}]
add:subModels; args=[Object { _queue={...}, attributes={...}, _escapedAttributes={...}, more...}, Object { length=3, models=[3], _byId={...}, more...}, Object {}]
add:subModels; args=[Object { _queue={...}, attributes={...}, _escapedAttributes={...}, more...}, Object { length=3, models=[3], _byId={...}, more...}, Object {}]
update:subModels; args=[Object { _queue={...}, attributes={...}, _escapedAttributes={...}, more...}, Object { length=3, models=[3], _byId={...}, more...}, Object {}]

If you don't see these change events, could you check which versions of backbone and backbone-relational you're using?

来源：https://stackoverflow.com/questions/7685791/backbone-relational-events-not-firing

标签

javascript

model

backbone.js

coffeescript

backbone-relational