Model validate() is not called properly about backbone HOT 12 CLOSED

This is actually working correctly...

When you call save() on a Model, the default implementation of Backbone with trigger two calls to set() (and thus, two calls to validate()) ... once on the client-side, before the model is sent to the server, and once again when the server responds with new attributes to be updated on the client.

Taking the Todo list as an example: If you toggle the checkbox on a todo item, you'll first get a call to validate() with just the {done: true} change to the attributes. Once LocalStorage has finished saving the model, you'll get another call to validate(), this time including the id (generated by the localstorage plugin), as well as the order.

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So how would you change my validate to make it work?

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Something like this...

validate: function(attrs) {
  if ("content" in attrs && attrs.content.length < 4) {
    return "Content is too short";
  }
}

And then:

var todo = new Todo();
todo.bind('error', function(err) { ... });

todo.set({content: ""});

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Well it still gets added even if it fails on the validation. I honestly see no value in the validate method when it works this way. I get new todo's without content even though the validate works as you said.

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I don't know if this is related, and will happily move this to a new issue ...

I found that calling the Collection.create method results in the validation being called with an empty attributes object, but creating a new model and then running the save method on that model triggers the validation correctly. Is the create method passing the attributes correctly to the model?

var item = new Pmm.ItemModel();
item.save({
    'name': this.$('input[name="name"]').val(),
    'date-start': this.$('input[name="date-start"]').val(),
    'date-until': this.$('input[name="date-until"]').val()
}, {error: this.onError, success: this.onSuccess});

Returns attributes in the validation method ...

Pmm.items.create({
    'name': this.$('input[name="name"]').val(),
    'date-start': this.$('input[name="date-start"]').val(),
    'date-until': this.$('input[name="date-until"]').val()
}, {error: this.onError, success: this.onSuccess});

Returns an empty attributes object in the model's validate method.

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beseku.

Does the thing you said still not append something useless to the view as you create an instance of the object?

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Nope, it seems to work fine...

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Are there any news on this issue? I also tried to use the validate() function and can't really get my head around this. It get's called twice, which is somehow understandably explained by jashkenas, but I still can't see a good reason for this behavior.

But besides this, keep up the good work on backbone. I really enjoy working with it.

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Hi I'm having a problem similar with the create method.
I expected the following to work:

  this.collection.create(newModel);
    {
      success:function() {
        this.collection.view.trigger("tripList:change")
      },
      error:function() {

// //TODO - implement somethign better?
}
});

but end up having to do this as the callback 'success' never seems to get called.
//HACK
//TODO - this is a hack - I don't know how to do this right now!
var that = this;
this.collection.fetch({
success:function() {
that.collection.view.trigger("tripList:change")
},
error:function() {
//TODO - implement somethign better?
alert('failed to load collection');
}
});

Haven't looked into it further than just implement the second bit of code. Is this the expected behaviour?

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I looked into the issue regarding validate not working correctly in the Todo's demo. This is what I tried and what worked for me:

Saving a 4 letter word:

window.Todo.prototype.validate = function(attrs) {
  console.log(attrs);
}

Object
content: "test"
done: false
order: 1
__proto__: Object

Object
content: "test"
done: false
id: "77c6f96e-71ae-0d12-bc83-091ac601cb8b"
order: 1
__proto__: Object

I then modify the code slightly:

window.Todo.prototype.validate = function(attrs) {
  if (attrs.content.length < 4) {
    return 'Todo is too short, need > 4 characters';
  }
};

window.Todo.prototype.initialize = function() {
  var _init = window.Todo.prototype.initialize;

  return function() {
    this.bind('error', function(model, msg) {
      console.log(msg);
    });
  };
}();

with the expected result Todo is too short, need > 4 characters in my console and the item not added.

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Please reopen if you have further questions.

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This should now be overhauled on master. Validations will get the complete new state instead of just the delta: ab164c4

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