Extending a child object with Knockout Mapping

Question

Consider this JSON object:

{
    "BusinessModels":[
        { 
            "Id":1,
            "Name":"Business to Business",
            "Businesses":[],
            "ReportTypes":[
                {...},
                {...},
                {
                    "Id":6,
                    "Name":"Risk",
                    "BusinessModelId":1,
                    "Reports":[
                        {
                            "Id": 4,
                            "Name": "Test",
                            "Value": ko.observable() // NEED TO ADD THIS PROPERTY USING MAPPING
                        },
                        {...}
                    ]
                }
            ],
        }
    ]
}

I'm trying to add the value using the following code, but it doesn't seem to work.

var mapping = {
    'BusinessModels': {
        create: function(options) {
            return new function() {
                var self = options.data;
                self.SelectedBusiness = ko.observable();
                self.Businesses.unshift({ Id: 0, Name: 'All Clients' });
                ko.mapping.fromJS(self, {}, this);
            };
        }
    },
    'Reports': {
        create: function (options) {
            return new function () {
                var self = options.data;
                self.Value = ko.observable();
                ko.mapping.fromJS(options.data, {}, this);
            };
        }
     }
};

var model = ko.mapping.fromJSON(raw, mapping);
ko.applyBindings(model);

I need to give a child object "Reports" a ko.observable object named Value. How do I go about doing this in ko.mapping?

Answer 1

Well, that was quick. I figured out the answer.

var mapping = {
    'BusinessModels': {
        create: function (options) {
            return new function () {
                var self = options.data;
                self.SelectedBusiness = ko.observable();
                self.Businesses.unshift({ Id: 0, Name: 'All Clients' });
                ko.mapping.fromJS(self, mapping, this);
            };
        }
    },
    'Reports': {
        create: function (options) {
            return new function () {
                var self = options.data;
                self.Value = ko.observable();
                ko.mapping.fromJS(self, mapping, this);
            };
        }
    }
};

Rather than using ko.mapping.fromJS(self, {}, this) I used ko.mapping.fromJS(self, mapping, this). The reason is because Reports is a nested object of BusinessModels.