I'm creating a BreezeJS model and I would like to have an array as one of the property values, but I'm unsure how that would be set under the dataProperties section of the model. Would anyone have a example of how to do this?
Yo just define the property in your model as:
arrayOrObjectProperty: { dataType: "Undefined" }
And it should be enough, also if you require some further processing, like expansion or formatting of the property (so in your controllers the data is ready) you could do it in the jsonResultsAdapter.
Related
I'm trying to retrieve the model, because I need to access certain attributes, but I cannot. I'm inside a view, which extends another one. This is how the view looks like:
var ImageGridControlView = GridControlView.extend({
//.... stuff ....
alert(this.model.get('property')) //This gives me an error in console and nothing is alerted.
});
In the class that the above code extends, the model can be retrieved, like this:
var GridControlView = ControlView.extend({
//.... stuff ....
alert(this.model.get('property')) //This shows the property value correctly
});
Why can't the model be retrieved from ImageGridControlView? What is the persistence of models across different classes, children, etc? I'm new to Backbone, and the official documentation only covers models superficially.
Your snippets are too small to actually find the problem, so we have to just guess. Most likely candidates are:
you are accessing this.model inside a function triggered by an event binding that is not properly bound, so this isn't actually your view instance. It could be a the source DOM element of the window object instead.
You aren't passing a model property in the options object provided to the view's constructor
I have an angular-rails resource with a property that consists of irregular data that is potentially quite complicated-- something like:
{ foo: [ { bar: 'baz', lol: [ { 'omg': ... etc
I built a directive which takes this data and drills down into it, dynamically rendering form fields for each object... I've got the data displaying perfectly, however the piece of the puzzle that's missing is, how can I take advantage of Angular's binding so that changing the value on the form input will actually update that attribute in the model?
Originally I was thinking this should be simple, as my code drills through the data structure, it can just be maintaining a path, so I'd end up with something like: 'myObject.foo.bar'
Then I could just pass that to the form input's ng-model attribute...... however, I could not get angular to recognize ng-model="path" where $scope.path = "myObject.foo.bar"... ng-model="{{path}}" did not work either.
My directive is using angular.forEach to drill down into this datastructure, and someone had mentioned to me that I should perhaps be using ng-repeat instead, but I wasn't sure if this is the correct way to go or not? I still feel like there should just be a way to do ng-model="path" and have that work...
Any guidance would be greatly appreciated.
To use dynamic property names, use array notation. I.e. myObject["foo"]["bar"]. Plunkr: http://plnkr.co/edit/W60F75?p=preview
Can you try setting an property on the scope with the value of the object itself and then refer it in the form element? Like below:
// In your script
$scope.obj = myObject;
// In your form
<input ng-model="obj.foo.bar" type="text" />
Let say you are defining a Backbone.js Model. From the documentation we have ...
new Model([attributes], [options])
This seems great for passing some default attributes to a model. When passed the model automatically inherits those attributes and their respective values. Nothing to do. Awesome!
On they other hand lets say we have a Collection of that model.
new Backbone.Collection([models], [options])
Okay, cool we can pass some initial models and some options. But, I have no initial models and no options I need to pass so let's continue. I am going to fetch the models from the server.
collection.fetch([options])
Well I don't have any options, but I want to pass some attributes to add to each models as it is fetched. I could do this by passing them as options and then adding them to the attributes hash in the initialize for the model, but this seems messy.
Is their a Backbone.js native way to do this?
You can pass the attributes as options to fetch and over-ride the collection's parse method to extend the passed options (attributes) on the response.
The solution would look like the following:
var Collection = Backbone.Collection.extend({
url:'someUrl',
parse:function(resp,options) {
if (options.attributesToAdd) {
for (var i=0;i<resp.length;i++)
_.extend(resp[i],options.attributesToAdd);
}
return resp;
}
});
Then to add attributes when you call fetch on the collection, you can:
var collection = new Collection();
collection.fetch({
attributesToAdd:{foo:'bar',more:'foobar'}
});
You may have to tweak the code a bit to work with your JSON structure, but hopefully this will get you started in the correct direction.
I wanted to attach some new calculated property to a complex json object returned from a REST Service. This can be easily achieved through KnockoutJS's Mapping pluggin.
But I have decided to go for AngularJS this time. Is there any modules/pluggins similar to knockout's mapping pluggin ??
my PROBLEM is as shown below:
JSON Returned from server is something like:
{
id:2,
name: 'jhon',
relatives:[
{id:1,name:'linda', score:{A:10,B:33,C:78} },
{id:2,name:'joseph', score:{A:20,B:53,C:68} },
{id:3, name:'keith', score:{A:40,B:83,C:30} }
]
}
in the above json object, I want to attach some calculated property to each objects inside "relatives" collection based on the score each relative has.
Try using
angular.extend($scope, data);
I'm also starting to use Angular, coming from Knockout and Durandal :) Hope this might work for you. The data should be accessible in your view ($scope) directly.
Edit: See this thread.
Basically in angular there is no thing similar to Observable variables.
AngularJS makes observing separately from $scope itself.
To make map from Json in AngularJS you can use angular.fromJson to bind data from Json.
To add fields to your scope you also can use angular.extend.
But anyway adding calculated field is thing that you need to make by yourself, for this purpose you can try to use watch methods: $scope.watch, $scope.watchGroup,
watchCollection.
Is always equivalent use one or the other?
These prints in console same things
class Model extends Backbone.Model
defaults:
some: 'thing'
other: 'item'
model = new Model
console.log model.attributes
console.log model.toJSON()
toJSON() is a standard method that the JavaScript JSON serializer looks for when serializing an object.
In the context of Backbone, if you override toJSON in your model you can change the format of values which get sent to the server when saving. For example you could filter out read only fields like time stamps.
attributes is the JavaScript object containing the model data, that's what gets altered when you use model.set(). Except if you don't use set() to alter values, then you bypass all the events and loose some of the benefits of backbone. So only use attributes directly if you know what you're doing.