I want to override backbone.sync i have already asked this but the problem is i don't quite get it. I need to know where to put the codes if i were to override the sync function.
If i put it on the model like this
model = Backbone.Model.extend({ sync:"" });
Then how should i call it? if i were to use the save method. Also i need to change the methodMap of create from POST to PUT. temporarily i resorted to this 'create': 'PUT', actually editing the backbone.js file ( iknow its not good ). Before i forgot i also need to add this
sendAuthentication = function (xhr) {
xhr.setRequestHeader('Authorization', auth)
};
As a beforeSend parameter since my server has authentication. Again where should i do it? Where should i go and put the codes? in my model? in my collection? or in my views? Any help? THank you.
update
Also can i override the sync on my collection? i mean can i have something like this?
collection = Backbone.Collection.extend({ sync:""});
The strategy behind Backbone framework is to make it simple for editing and flexible for every need. So if you look up the source code you'll find out that every method, which calls Backbone.sync in fact calls first "this.sync".
From the Backbone manual you can read :
The sync function may be overriden globally as Backbone.sync, or at a
finer-grained level, by adding a sync function to a Backbone
collection or to an individual model.
So you have two options
Option One - Replacing global Backbone.sync function
If you override the global Backbone.sync you should place your code in your global application file ( actually anywhere you want, but it must be evaluated ( executed ) at your initial javascript loading, to work as expected
// Anywhere you want
Backbone.sync = function(method, collection, options) {
console.log(method, collection options)
}
This will override Backbone.sync and actually will display on your console what is called every time you call collection.fetch, save, delete, etc.
Here you have no default Methodmap, infact you have nothing else except the arguments :
method - which is a string - 'read', 'create', 'delete', 'update'
collection - which is your collection instance which calls the method
options - which has some success, error functions, which you may or may not preserve.
Debug this in your browser, while reading the Backbone source code, it's very easy to understand.
Option Two - Adding to your model/collection sync method
This is used if you wish to use the default Backbone.sync method for every other model/collection, except the one you specifically define :
mySocketModel = Backbone.Model.extend({
sync : function(method, collection, options) {
console.log('socket collection '+this.name+' sync called');
}
});
Partners = new mySocketModel({ name : 'partners' });
Users = new mySocketModel({ name : 'users' });
Log = new Backbone.Collection;
So if you call Partners.fetch() or Users.fetch(), they won't call Backbone.sync anymore, but yor Log.fetch() method will.
Related
I have an API in ExpressJS and a middleware that gets executed before each endpoint controller:
app.use(segregationMiddleware);
app.get('/some-endpoint', controller1);
app.get('/some-endpoint-2', controller2);
The segregationMiddleware is used to look for some parameters in the request and then it calculates a value that then is stored in the request object as req.locals.domain so the controllers can access it.
In each Mongoose model, I define a field named domain using a Mongoose plugin (so I don't have to do it every time). That field is used to segregate my assets. This means that when the segregationMiddleware populates req.locals.domain = 'foo' for example, if I make a model.find({}) I want to get only assets that have { domain: 'foo' }. Same thing if I try to update, save, delete, and so.
Of course, I can just simply modify the query on each controller since I have accesso to req, but I need to do it every time and I need to remember it for finds, findAndUpdate, save, and soo... sooner or later I'm gonna forget it.
I can define some hooks in Mongoose that will modify the query using a plugin so it adds the domain constraint to the query so I don't have to do it in the controller BUT I don't have the current req object in the Mongoose plugin unless I pass it, and the only way that come to my mind is to abstract the DB methods in the plugin, so in the controller, I do something like this:
model.safeFind(req, query);
And in the plugin I define safeFind like:
safeFind = () => {
const theRealQuery = Object.assign({}, query, { domain: req.locals.domain });
return this.find(query);
}
BUT, in this way, I need to redefine each DB query function (find, findOne, update, save...) and I need to remember to use the safe methods. Then again, I'm going to forget it sooner or later.
Is there a way I can still use the regular Mongoose methods from the controller and have the plugin somehow modify the query for every method using the current req object?
I have a route that creates a new record like so:
App.ServicesNewRoute = Ember.Route.extend({
model : function() {
return this.store.createRecord('service');
},
setupController: function(controller, model) {
controller.set('model', model);
},
});
Then I bind that model's properties to the route's template using {{input type="text" value=model.serviceId ... }} which works great, the model gets populated as I fill up the form.
Then I save record:
App.ServicesNewController = Ember.ObjectController.extend({
actions : {
saveService : function() {
this.get('model').save(); // => POST to '/services'
}
}
});
Which works too.
Then I click the save button again, now the save method does a PUT as expected since the model has an id set (id: 102):
But then when I look at the PUT request in Dev Tools, I see that the id attribute was not serialized:
As a result, a new instance is created in the backend instead of updating the existing one.
Please ignore the serviceId property, it is just a regular string property unrelated to the record id which should be named just id.
I don't know why the id is not being serialized... I cannot define an id property on the model of course since Ember Data will not allow it, it is implicit. So I don't know what I am missing...
Any help is greatly appreciated!
The base JSONSerializer in Ember-Data only includes id in the payload when creating records. See DS.JSONAdapter.serialize docs.
The URL the RestAdapter generates for PUTting the update includes the ID in the path. In your case I believe it would be: PUT '/services/102'.
You can either extract it from the path in your backend service. Or you should be able to override the behavior of your serializer to add the id like this:
App.ServiceSerializer = DS.JSONSerializer.extend({
serialize: function(record, options) {
var json = this._super.apply(this, arguments); // Get default serialization
json.id = record.id; // tack on the id
return json;
}
});
There's plenty of additional info on serialization customization in the docs.
Hope that helps!
Initially I used ronco's answer and it worked well.
But when I looked at ember data's source code I noticed that this option is supported natively. You just need to pass the includeId option to the serializer.
Example code:
App.ApplicationSerializer = DS.RESTSerializer.extend({
serialize: function(record, options) {
options = options ? options : {}; // handle the case where options is undefined
options.includeId = true;
return this._super.apply(this, [record, options]); // Call the parent serializer
}
});
This will also handle custom primary key definitions nicely.
Well, as far as I know it's a sync issue. After first request you do the post request and then, it has been saved in the server, when you click next time the store haven't got enough time to refresh itself. I've got similar issue when I've created something and immediately after that (without any transition or actions) I've tried to delete it - the error appears, in your case there's a little bit another story but with the same source. I think the solution is to refresh state after promise resolving.
Trying to populate a Collection from a list of values, I am getting an error about the Collection's model's prototype being undefined. Looking at this question about a similar problem, I have checked that the Model is actually created before the collection is instanced, to the best of my ability.
The error is being thrown in one of the event handlers of the Marionette CompositeView that holds the Collection, after fetching the data from the server and trying to reset the collection with the list of values from the data which should be populated into it.
Note: Using Backbone 0.9.10
The Model
MyItemModel = Backbone.Model.extend({});
The Collection
MyCollection = Backbone.Collection.extend({
model: MyItemModel
});
The CompositeView's relevant code
MyCompositeView = Backbone.Marionette.CompositeView.extend({
initialize: function(options) {
_.bindAll(this);
this.model = new MyCompositeViewModel();
this.collection = new MyCollection();
},
//This event handler gets properly fired and run.
on_event: function() {
var that = this;
// The data comes through fine with this `fetch`
this.model.fetch({success: function() {
var collection_results= that.model.get("collection_results");
// The error fires in this line
that.collection.reset(collection_results);
that.render();
});
}
})
The error
The error happens in the add function in Backbone, when doing a get for the model object, checking to see if it is a duplicate. The failing code is here:
// Get a model from the set by id.
get: function(obj) {
if (obj == null) return void 0;
// The error originates from this line
this._idAttr || (this._idAttr = this.model.prototype.idAttribute);
return this._byId[obj.id || obj.cid || obj[this._idAttr] || obj];
},
this._idAttr || (this._idAttr = this.model.prototype.idAttribute);
Here, the this.model.prototype.idAttribute fails because the prototype for the model is not defined.
Why is this happening, and how can it be fixed?
Thanks a lot!
The reason is, in Babkbone 0.9.10, if you call collection.reset(models) without options, the models will be passed to collection.add() which strictly needs real models as argument.
But, in fact, the arguments you passed are not real models. They are just an array of hash attributes.
Two options to fix:
Option 1: Call the reset with a parse option
that.collection.reset(collection_results, {parse: true});
Then reset will parse the array of hashes and set them as model.
Option 2: Upgrade to latest version Backbone 1.1.0.
Here reset() no longer pass responsibility to add() but use set() smartly. This option is recommended. And you don't need options here.
that.collection.reset(collection_results)
Another point
May I suggest you not to define model in CompositeView? CompositeView is for collection, not model. Of course I understand the model here is just to hold and fetch some data, but it would be really confusing for the code to be read by another developer, as well as your own maintaining.
To get bootstrapped data, you can load the data at first request and use conventional way to put it into collection. http://backbonejs.org/#FAQ-bootstrap
I'm writing a practice Backbone app, with Rails backend API, and I'm confused about the behavior of save on Backbone models.
Let's say a Team has many Players, and I want to save a team with numerous players in a single POST.
So in Rails I have:
class Team < ActiveRecord::Base
has_many :players
accepts_nested_attributes_for :players
end
class Player < ActiveRecod::Base
belongs_to :team
end
and for backbone client, I have a Player model and a Players collection defined (not shown)
and then the containing Team model (NOTE: no Teams collection)
Demo.Models.Team = Backbone.Model.extend({
urlRoot: '/teams',
defaults: {
'team_size': 12
},
initialize: function() {
this.players = new Demo.Collections.Players());
},
toJSON: function() {
var json = _.clone(this.attributes);
json.players_attributes = this.players.map(function(player) {
return player.toJSON();
});
return json;
}
}
When I examine my stringified JSON in the browser, everything looks good:
{"team_size":12, "players_attributes":[{"name":"Fred"},{"name":"Jim" },{"name":"Mark"}]}
Checking the server logs, the lone top level attribute ('team size') is repeated, once at the top level, and then repeated under a root key.
Started POST "/teams" for 127.0.0.1 at 2012-06-07 13:39:40 -0400
Processing by TeamsController#create as JSON
Parameters: {
"team_size"=>12, "players_attributes":[{"name":"Fred"},{"name":"Jim" },{"name":"Mark"}]},
"team"=>{"team_size"=>12}
}
I have a few questions:
What's the best way to ensure the player_attributes are nested inside the root key? I (So that I can do a nested save inside TeamController, in the standard rails manner: (i.e. Team.create(params[:team]) ) I can accomplish this with some javascript hackery inside toJSON, but I'm guessing there's an easier, cleaner way.
Is this standard, desirable behaviour? To send duplicates of attributes like this? I guess there's no harm, but it doesn't smell right.
Am I not defining the url / urlRoot correctly or some such?
thanks
1- You have to override the toJSON method in order to include the model name as the root of the JSON element sent to the server.
toJSON: function() {
return { team: _.clone( this.attributes ) }
},
Since you are already messing and overriding this method I don't see any reasons not to go this way.
2- This is a very strange behavior you're describing. Try:
class Team < ActiveRecord::Base
self.include_root_in_json = false
end
It will probably eliminate Rails duplicate params parsing. Another advantage you get from this is that Rails won't include the team as a root element of its generated JSON to the client.
3- Your definition of urlRoot is just fine.
I arrived here while looking for same issue. So even it's an old question I think it's worth giving the answer.
I actually found a Rails setting that explain these duplicate attributes: wrap_parameters
http://apidock.com/rails/v3.2.13/ActionController/ParamsWrapper/ClassMethods/wrap_parameters
Just set it to an empty array, and rails won't try to wrap parameters coming from your JSON requests.
Although you can use the toJSON hack mentioned by others, this is actually not such a good idea. For one, it produces an inconsistent result between sync and save with {patch: true} (this inconsistency is because the sync method calls toJSON if you don't patch, but doesn't call toJSON if you have patch set to true)
Instead, a better solution is to use a patched version of Backbone that overload the sync method itself. The backbone-rails gem does this automatically, or you can pull backbone_rails_sync.js into your own app. A more complete answer to this question can be found here: Backbone.js and Rails - How to handle params from Backbone models?
The title of the question pretty much sums it up, I'd like my view to respond differently to a model instances initial save vs any future saves. Right now I'm grabbing the model's isNew attr before I save and then triggering a custom event, but I was wondering if there was anything built in?
Checking model.isNew() is the built-in way of telling whether the initial save has happened yet. If checking isNew is working for you, keep on doing it.
The initial save should issue an ID for the object, so you could bind a function to "change:id" and it would execute after the initial save succeeds. Or you could add logic to the "success" and "error" callbacks of create().
With help from this answer, I came up with the following solution:
var originalSync = Backbone.sync;
Backbone.sync = function(method, model, options) {
console.log(method);
originalSync.apply(Backbone, [method, model, options]);
};
I can now check what method is being called.