Validating complex attribute as a whole

[juodaspaulius]

Lets say the model has attribute which value is complex object such as:

complex : { 
    one: "val1",
    two: ""
}

Currently, due to flattening, this attribute can only be validated using validation keys complex.one and complex.two, but not on a whole object complex. What I would really like to do is to specify custom validator on complex, for example like this:

validation: {
    complex: function(val){
          if (val && val.one && val.two){
               return "Only one of values allowed";
          }
    }
}

To make it work I minorly modified flatten function to include the key of complex object in addition to other flattened nested keys.
My modified flatten function is:

var flatten = function (obj, into, prefix) {
    into = into || {};
    prefix = prefix || '';

    _.each(obj, function(val, key) {
        if(obj.hasOwnProperty(key)) {
            if (val && typeof val === 'object' && !(
                val instanceof Array ||
                val instanceof Date ||
                val instanceof RegExp ||
                val instanceof Backbone.Model ||
                val instanceof Backbone.Collection)
            ) {
                flatten(val, into, prefix + key + '.');
            }
            // Removed this else statement so that the key of the complex is always added as well
            // else {
                into[prefix + key] = val;
            // }
        }
    });

What do you think, perhaps it could be included into the upstream?

[blikblum]

I like the idea, this will allow to validate also properties in the middle of the obj path

[platinumazure]

Great idea! If no one else wants to, I wouldn't mind writing a pull request and tests for this feature.

[chiefGui]

@platinumazure please, do it.

[blikblum]

I suggest to merge #260 first to avoid conflicts