passing variables in 'bind' trigger - binding

Question

I'm using backbone.js with jquery droppable.
The problem I'm having is that upon entering the .droppable function, the 'this' no longer refers to the backbone object. I've read Yehuda Katz article about understanding 'this', but I still don't understand how to 'solve' the problem.
http://yehudakatz.com/2011/08/11/understanding-javascript-function-invocation-and-this/
I thought the way out of the issue would be to just bind the model changes event to trigger a method, but I need to pass a variable to the method, and I can't figure out how to do that.
here's an excerpt of my code. On the line MyApp.User.Trigger('new_class');, is there a way to add a variable?? How do I put that in the bind event??
initialize: function(){
user = MyApp.User;
MyApp.User.bind('new_class',this.save, this);
this.render();
},
render: function(){
$('li.empty').droppable({
hoverClass: "ui-state-active",
start: function(e){
$(this).click('unbind');
},
drop: function(event, ui){
var add_class_to_user = $(this).attr('data-id');
MyApp.User.Trigger('new_class');
}
})
},
save: function(class){
var add_class = new Myapp.Model.Class({
class_id: class,
user_id: user.id
});
add_class.save()
}

Answer 1

I'm not sure i understand what you are asking,
so i will answer both :
on the context of This:
and why don't you store reference this into a new variable?
...
render: function(){
// here we put this in a new variable myView.
var myView = this;
$('li.empty').droppable({
hoverClass: "ui-state-active",
start: function(e){
$(this).click('unbind');
// here you can use myView instead of this, if you want something from your view.
myView.model.set({'name', 'newname'});
},
drop: function(event, ui){
var add_class_to_user = $(this).attr('data-id');
MyApp.User.Trigger('new_class');
}
})
},
...
on the question of passing parameters to an event
...
render: function(){
$('li.empty').droppable({
hoverClass: "ui-state-active",
start: function(e){
$(this).click('unbind');
},
drop: function(event, ui){
var add_class_to_user = $(this).attr('data-id');
MyApp.User.Trigger('new_class', add_class_to_user);
}
})
},
...
in your user model you should of course do this: (or more likely in another view, you can bind to that event on the user model)
MyApp.User.bind('new_class', function(myparameter) {
alert('yay, my parameter is:' + myparameter);
$('#myElement').addClass(myparameter);
});
example in jsfiddle: can be found here....
http://jsfiddle.net/saelfaer/MWuHj/