Destroying all models from a collection

[luniki]

Not so obviously 'collection.invoke("destroy")' does not work. How would one empty a collection?

[martindrapeau]

I ended up extending both Model and Collection with methods for those. Here those are:
MyModel = Backbone.Model.extend({
destroy : function(options) {
options || (options = {});
if (this.selected) this.unselect(options);
if (!options.silent) this.trigger('destroy', this, options);
if (this.collection) this.collection.remove(this, options);
return this;
}
});
MyCollection = Backbone.Collection.extend({
clear: function(options) {
options || (options = {});
while (this.length > 0) {
this.at(0).destroy(options);
}
if (!options.silent) this.trigger('clear', this, options);
return this;
}
});

[jashkenas]

So, there are two things here. The first is destroying all the models in a collection on both the client and the server, and the second is simply removing all the models from a collection, client-side.

The reason why backbone doesn't have the former built-in is because it's not standard in basic REST, and we won't want to encourage folks to be submitting 100 individual HTTP requests, one to destroy each item. You should have a special endpoint to perform a bulk destroy, and then empty your collection client-side, which can be done like so:

collection.refresh();

[martindrapeau]

What happens if you have code that watches a particular model? It would never know it got removed.
Would be nice to have the event triggered but the REST call not made. Hence in my implementation the destroy/clear are not REST (no calls to server). I have specialized methods delete/deleteAll to do that. But each model does trigger the destroy event so watchers get notified. I'll admit I don't like my current implementation because it is not clean. So if server calls could be made optional, and events always triggered, I'd be happy.

[jwogan5]

@martindrapeau

I have been searching for a long time but I came across this and was wondering if you could send me your deleteAll method for a backbone collection. Here is my issue. I hit an api to get a list of items and I store them in a collection. I then want to completely remove all items in the collection and refresh them with a nw list. I can do that locally but when I call fetch on the collection all the items come back again as they are not removed from the server. I can also do the whole removing one item at a time from the server but that can take 15 seconds to finish if I have about 200 items. Preferably I want to both call refresh locally and one call to remove all items on the server to speed up the removal process. Any help would be appreciated.