Backbone does not offer a filtering mechanism on events, but you could alter your state model to trigger custom events with the signature you wish.
For example, let's say state
is an instance of this class
var EqualBindModel = Backbone.Model.extend({
arm: function(attribute, watchvalue) {
this.on('change:'+attribute, function(model, val, options) {
if (watchvalue === val)
model.trigger('change:'+attribute+'='+val, model, val, options);
});
}
});
you could then setup your custom event with
var state = new EqualBindModel();
state.arm('pageNumber', 2);
and listen to with
state.on("change:pageNumber=2", function(model, value, options) {
console.log('event change:pageNumber=2');
});
And a demo http://jsfiddle.net/ZCab8/1/