I'm creating a backbone view for displaying a list of folders created by user in my webapp. but I want to have a default entry like no folder to be displayed in the list as well.
Instead of inserting the DOM inside the view, I want to just add a model to the collection which does not get synced to server but is just used to be rendered in the view.
Is there a way I can do this? I tried this an failed...
var def = {'name': 'none', 'selected': 'true'};
var coll = new app([def]);
// model here
var appitem = Backbone.Model.extend({
defaults: {
name: '',
id: '',
selected: 'false'
}
});
// collection here
app = Backbone.Collection.extend({
model: appitem,
url: '/apps'
});
You should not alter your models based on what the view needs.
If you need to display a 'no folder' entry, than it belongs in the view.
Don't complicate your life by adding data without meaning to the model layer. Keep it in the view.
Related
formGrid=me.abstractComponent.query('grid[itemId=grid]')[0],
Objmodel= Ext.create('Ext.document.model.GridModel');
formStore = Ext.create('Ext.data.Store',{
model:Objmodel,
data: data
});
formGrid.bindStore(formStore);
formStore.load();
I've been trying to load the store using the model, but error occurs saying that model not found. Is there any way such that i can load the model from another file in store above?
Store model attribute means you have to give the definition of Model not instance of model
Ext.define('app.model.User', {
extend: 'Ext.data.Model',
fields: ['first', 'last']
});
var store = Ext.create('Ext.data.Store',{
model: 'app.model.User'
});
Now if you want to add data to grid using model
var model = Ext.ModelManager.create({
first: 'Ed',
last: 'Spencer'
}, 'app.model.User');
store.add(model)
I'm really confused about something regarding collections and models in backbone. Since I'm learning backbone, I haven't been able to fully understand it. I'm working on a backbone project that displays the question with branching logic; the next question that appears is based on the answer to the current question. I created a collection and model that stores (if this is the proper terminology) the response which is then retrieved in a separate view (an email form view) where these responses are added to the message box. Here's my collection to the response.
App.Collections.ResponseCollection = Backbone.Collection.extend({
model: App.Models.ResponseModel
});
and this is the model:
App.Models.ResponseModel = Backbone.Model.extend({
idAttribute: "_id",
defaults: {
response: '',
answer: ''
}
});
which is created like this:
saveResponse: function (qModel, option) {
var qid = qModel.get('question_id');
var mod = this.response.find(function (model1) {
return model1.get('_id') == qModel.get('question_id');
});
if (typeof (mod) == "undefined") {
var responseModel = new App.Models.ResponseModel({
_id: qModel.get('question_id'),
response: qModel.get('question'),
answer: option
});
this.response.add(responseModel);
}
else {
mod.set('answer', option);
}
},
In the view which displays the questions, I instantiated the model and added the response to it which is then added to the collection. This works fine - the responses are added to the model and also it is added to the collection. Now, I want to retrieve this collection and fetch the response from each model so that it's added in the textarea. So, this is what I did in the email view..
var options = new App.Collections.ResponseCollection();
But when I print the collection in console, this is what I see - there's no model in the collection
child {length: 0, models: Array[0], _byId: Object, constructor: function, model: function…}
These data are not saved and retrieved from the database. These responses are added to the model only to retrieve it later to be added to the email form.
I'm confused why it doesn't show me any models in the collection
I'm new to Backbone and on fetching a collection, I can see the server return all 15 collections. The fetch success returns all 15 models in the response object but the collection object has only the last of the 15 models.
var BracketModel = Backbone.Model.extend({
defaults: {
id: '',
name: '',
title: ''
},
urlRoot: 'http://test.com/bracket/rest.php',
.....
}),
var BracketsCollection = Backbone.Collection.extend({
url: 'http://test.com/bracket/rest.php?op=list',
model: BracketModel,
}),
bracketCollection.fetch({
success: function (collection, response) {
// Collection.models only has one model, response has 15
var bracketsView = new BracketsView({collection: collection});
},
Try
var bracketsView = new BracketsView({collection: response});
Or
var bracketsView = new BracketsView({collection: collection.toJSON()});
I haven't tested it now, but if I remember well, both are equivalent.
The first parameter returns the collection object, which gives you access to different collection attributes. The second parameter returns 'an array containing the attributes hash of each model in the collection', which is likely the thing you are looking for.
The pattern that I usually go with for passing a collection to a view goes like this:
var bracketCollection = new BracketsCollection();
var view = new brackatsView({collection: bracketCollection});
brackCollection.fetch();
Then inside of your view's initialization method do this:
this.listenTo(this.collection, 'sync', this.render);
What this all is doing is creating your collection and your view, and then when you create the view you are telling it about the collection. Calling fetch on the collection is an asynchronous event that will fire a 'sync' even when it is done. The view will listen for this sync event, and when it happens will call the render function.
I have a backbone collection.I want to add or remove some models dynamically in the collection. But if i am using collection.set() method then it is going to remove first all elements and then it will add all elements again.
What i want to do is trigger add event of collection for those whose are really new added and trigger remove events for those whose are removed from previous collection.
Here is a example [http://jsfiddle.net/PkJCx/2/]
From the docs
The set method performs a "smart" update of the collection with the
passed list of models. If a model in the list isn't yet in the
collection it will be added; if the model is already in the collection
its attributes will be merged; and if the collection contains any
models that aren't present in the list, they'll be removed.
It is also a good idea to provide `idAttribute' to the model so that the collection identifies that based on the id. Otherwise the collection would not know if the model is a new one or not.
So after setting the id and using set, you can see that is performs a smart update
$(function () {
var MyModel = Backbone.Model.extend({
// This attribute should be set as a default
defaults: {
Name: ''
},
// Set the id attribute so that the collection
// know that it is the old model
idAttribute: 'id'
});
var Coll = Backbone.Collection.extend({
model: MyModel
});
var models = [{
Name: 'A',
id: 1
}, {
Name: 'B',
id: 2
}];
var collection = new Coll(models);
collection.bind('add', function (model) {
alert('addb')
});
collection.bind('remove', function () {
alert('add')
});
models = [{
Name: 'A',
id :1
}, {
Name: 'B',
id: 2
}, {
Name: 'C',
id: 3
}];
collection.add(models);
});
Check Fiddle
It will not try to remove the other 2, but Backbone is smart enough to identify that 2 of them are old models and then just merges the newer one into the collection.
When creating new collection (Choices) I want to set a property on it (ex: _question) which links back to the containing Model (MultipleChoiceQuestion)
This took me quite a bit of time to figure out, so in case somebody in the future has this problems...here's the code I ended up writing.
I discovered, unlike Model, Collection's initialize() function accepts 2 parameters. The first is models (which is a list of models you can initialize the collection with). The second is options (what you want). For a while my Collection started out with 1 model inside and I couldn't figure out why. Turns out I was passing my options into the models field.
THE CONTAINING MODEL:
m.MultipleChoiceQuestion = Backbone.Model.extend({
initialize: function(){
//NULL as first parameter because we don't want models
this.choices = new c.Choices(null, {
_question: this //this is referring to current question
}); //choices Collection is this
}
});
THE COLLECTION
c.Choices = Backbone.Collection.extend({
initialize: function(models, options){
this._question = options._question;
},
model: m.Choice
});
I actually found that although my 1st answer technically works, there's a plugin that makes care of storing collections in models (and creating appropriate One->Many, One->One and Many->One relationships
https://github.com/PaulUithol/Backbone-relational
Using that plugin you store the parent question as an ATTRIBUTE
m.MultipleChoiceQuestion = Backbone.RelationalModel.extend({
relations: [{
type: Backbone.HasMany,
key: 'choices', //says to store the collection in the choices attribute
relatedModel: m.Choice, //knows we are talking about the choices models
includeInJSON: true, //when we do toJSON() on the Question we want to show serialize the choices fully
reverseRelation: {
key: 'question', //in the CHOICE object there will be an attribute called question which contains a reference to the question
includeInJSON: false //when we do .toJSON on a CHOICE we don't want to show the question object (or maybe we want to show the ID property in which case we set it to "id")
}
}],
coolFunction: function () {
this.get('choices').each(function(choice){
choice.doSomethingChoicey();
});
}
});
So now if we are in the choices model we can fully reference anything in the parent question:
m.Choice = m.RelationalModel.extend({
coolFunction: function(){
this.get('question').doSomemethingQuestiony();
var question_numer = this.get('question').get('question_number');
}
});