Binding Multiple Event Types In Backbone Views
I was wondering if it is possible to bind multiple event types in backbone within a single line. Consider the following: var MyView = Backbone.View.extend({ id: 'foo', even
Solution 1:
It's impossible for views jQuery events, which are bound through delegateEvents
. It's is possible for backbone events, though:
book.on("change:title change:author", ...);
Solution 2:
For anyone interested I ended up overriding delegateEvents
in Backbone.View.
There are only a few modified lines to get the desired functionality.
You can see a diff in my commit on github
Here is delegateEvents
in its modified state:
delegateEvents: function(events) {
if (!(events || (events = getValue(this, 'events')))) return;
this.undelegateEvents();
for (var key in events) {
var method = events[key];
if (!_.isFunction(method)) method = this[events[key]];
if (!method) throw new Error('Method "' + events[key] + '" does not exist');
var match = key.match(delegateEventSplitter);
var eventTypes = match[1].split(','), selector = match[2];
method = _.bind(method, this);
var self = this;
_(eventTypes).each(function(eventName) {
eventName += '.delegateEvents' + self.cid;
if (selector === '') {
self.$el.bind(eventName, method);
} else {
self.$el.delegate(selector, eventName, method);
}
});
}
}
Solution 3:
We could also do it as below. With the advantage to manage space between each event.
Add it in Backbone directly :
delegateEvents: function(events) {
events || (events = _.result(this, 'events'));
if (!events) return this;
this.undelegateEvents();
for (var key in events) {
var method = events[key];
if (!_.isFunction(method)) method = this[method];
if (!method) continue;
var match = key.match(delegateEventSplitter);
this.delegate(match[1], match[2], _.bind(method, this));
}
return this;
}
Override delegateEvents method :
Backbone.View.prototype.originalDelegateEvents = Backbone.View.prototype.delegateEvents;
Backbone.View.prototype.delegateEvents = function(events) {
events || (events = _.result(this, 'events'));
if (!events) return this;
this.undelegateEvents();
for (var key in events) {
var method = events[key], combinedEvents = key.split(',');
if (!_.isFunction(method)) method = this[method];
if (!method) continue;
for(var i = 0, match = null; i < combinedEvents.length; ++i) {
match = combinedEvents[i].trim().match(/^(\S+)\s*(.*)$/);
this.delegate(match[1], match[2], _.bind(method, this));
}
}
return this;
};
We could now manage events in one line :
events: {
'click a[data-anchor], wheel, keydown': 'scroll'
}
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