backbone validate function does not work

Question

I am using backbone validate function but it gives this error again Uncaught TypeError: Object [object Object] has no method 'apply'. I really have no idea why is it giving me this error.

Here is my code

$(function () {
var Veh = new Backbone.Model.extend({
    validate: function (attrs) {
        var validColors = ['white','red', 'black'];
        var colorIsValid = function (attrs) {
            if(!attrs.color) return true;
            return _(validColors).include(attrs.color);
        }
        if(!colorIsValid(attrs)) {
            return 'wrong color';
        }
    }
});
var car = new Veh();
car.on('error', function (model, error) {
    console.log(error);
});
car.set('foo', 'bar');
});

score 1 · Accepted Answer · edited May 23 '17 at 12:12

Update: The error is the use of new. Don't do new when using Backbone.extend. This is because you are creating a class and not an object.

$(function () {
var Veh = Backbone.Model.extend({
    validate: function (attrs) {
        var validColors = ['white','red', 'black'];
        var colorIsValid = function (attrs) {
            if(!attrs.color) return true;
            return _(validColors).include(attrs.color);
        }
        if(!colorIsValid(attrs)) {
            return 'wrong color';
        }
    }
});

Notice var Veh = Backbone.Model.extend instead of

var Veh = new Backbone.Model.extend

See this question for the side effects of using new inadvertantly.

If you evaluate immediately with no parameters you will get an error immediately as attrs is not defined — Tallmaris, Oct 21 '12 at 10:34

score 1 · Answer 2 · answered Oct 21 '12 at 10:37

If you have the unminified version you can step through thte code and see where the error is. What I would do immediately, anyway, is change the param name of the colorIsValid function so it's not the same as the outer function...

validate: function (attrs) {
    var validColors = ['white','red', 'black'];
    var colorIsValid = function (modelAttrs) {
        if(!modelAttrs.color) return true;
        return _(validColors).include(modelAttrs.color);
    }
    if(!colorIsValid(attrs)) {
        return 'wrong color';
    }
}

backbone validate function does not work

2 Answers2