I am trying to create a backbone.js model with dynamic keys but can't seem to get it done right.
Here's my model:
window.MyModel = Backbone.Model.extend({
myDynamicVar : "country",
urlRoot: "api/myModel",
defaults: {
"id": null,
this.myDynamicVar : "USA",
"country": {
"route":"test/test/test",
"class":".usa2",
"txt":"USA 2"
},
"region": "California",
"year": "",
"description": "",
"picture": ""
}
});
Here I am trying to have myDynamicVar replaced by its content in my model. Any thought how I could get this done? Thanks in advance, Jimmy
You cannot use a variable in defining the object key. You can try something like this.
ReplyDeletewindow.MyModel = Backbone.Model.extend({
myDynamicVar : "country",
urlRoot: "api/myModel",
defaults: {
"id": null,
"country": {
"route":"test/test/test",
"class":".usa2",
"txt":"USA 2"
},
"region": "California",
"year": "",
"description": "",
"picture": ""
}
});
window.MyModel.defaults[this.myDynamicVar] = "USA";
You won't be able to do that directly; the left side of the ":" in an object literal must be a constant. What you can do is this:
ReplyDeletewindow.MyModel = Backbone.Model.extend({
myDynamicVar : "country",
urlRoot: "api/myModel",
defaults: function(fieldName) {
var value = {
"id": null,
"country": {
"route":"test/test/test",
"class":".usa2",
"txt":"USA 2"
},
"region": "California",
"year": "",
"description": "",
"picture": ""
};
value[fieldName] = "USA";
return value;
}(this.myDynamicVar)
});
edit — ah, I just noticed that "myDynamicVar" itself is part of the outer object. There's no way to refer to it with this in such a way, so if that's what you're trying to do the code would be different:
window.MyModel = Backbone.Model.extend(function() {
var value = {
myDynamicVar : "country",
urlRoot: "api/myModel",
defaults: {
"id": null,
"country": {
"route":"test/test/test",
"class":".usa2",
"txt":"USA 2"
},
"region": "California",
"year": "",
"description": "",
"picture": ""
}
};
value.defaults.[value.myDynamicVar] = "USA";
return value;
}());
If you want myDynamicVar itself to be dynamic, then you could pass it in as a parameter:
window.MyModel = Backbone.Model.extend(function(whichProperty) {
var value = {
myDynamicVar : "country",
urlRoot: "api/myModel",
defaults: {
"id": null,
"country": {
"route":"test/test/test",
"class":".usa2",
"txt":"USA 2"
},
"region": "California",
"year": "",
"description": "",
"picture": ""
}
};
value.defaults.[value[whichProperty]] = "USA";
return value;
}("myDynamicVar"));