Question

What I am trying

On Save or Delete of my form a simple notification is poped-up to user

What I have done

events :{
    '#save-button click' : 'onSaveBUttonClick',
    '#delete-button click' : 'onDeleteButtonClick'
};

onDeleteButtonClick = function(){

    //popup appears to confirm delete
    this.model.on('sync',function(model){ 
        model.off('sync');
        alert("project deleted"); 
    },this);
    this.model.destroy();
}

onSaveBUttonClick = function(){

    //popup appears to confirm delete
    this.model.on('sync',function(){ 
        model.off('sync');
        alert("project Saved"); 
    },this);
    this.model.save(); 
}

The problem

I click on the delete button and say , select , cancel. Here the model.on('sync') is bound to the model.

Now when I click save , and confirm , the model.on('sync') is called twice (one bound by delete button and one bound by save button).

So I am getting 2 pop-ups Project deleted first and project saved after it.

How can I avoid this?

Answer 1

You can use the success options in model.save and model.destroy

destroy model.destroy([options])
Destroys the model on the server by delegating an HTTP DELETE request to Backbone.sync. Returns
a jqXHR object, or false if the model isNew. Accepts success and error
callbacks in the options hash.

save model.save([attributes], [options])
[…]
save accepts success and error callbacks in the options hash.

Your methods could look like

onDeleteButtonClick = function(){
    this.model.destroy({
        success: function() {
            alert("project deleted"); 
        }
    });
}

onSaveBUttonClick = function(){
    this.model.save(null, {
        success: function() {
            alert("project saved"); 
        }
    }); 
}