How to implement a simple non persistent datastore in ember? I've tried to follow the Article of Jiri Zajpt but somehow i can't figure out how it's working. I think i need a deeper understanding of the datastore concept.
As i understand the concept correctly, the datastore provides methods to deal with data and storing these data into an application wide accessible object, right?
This is what i've so far:
Ember App
App = Ember.Application.create();
App.DataSource = Ember.Object.extend({
store : null,
getTickets: function(callback) {
var store = this.store;
jQuery.get('/data/tickets.json', function(data) {
store.pushObjects(data);
callback(store);
});
}
});
App.dataSource = App.DataSource.create({
store: App.store
});
App.Store = Ember.ArrayProxy.extend({
content: [],
init: function() {
this._super();
}
});
App.store = App.Store.create();
Loaded JSON
[
{
"id":"1",
"type":"bug",
"prority":"normal",
"status":"open",
"title":"Router is stopping at a non-leaf state",
"discription":"Lorem ipsum"
},
{
"id":"2",
"type":"Change request",
"prority":"normal",
"status":"open",
"title":"Add Ember.Deferred mixin",
"discription":"Lorem ipsum"
}
]
Note: The code above has currently no output. Here is a Fiddle to play with: http://jsfiddle.net/WHqVJ/
I know the ember-data project but i think it's a little bit to much for my project and also i want to learn to create a datastore.
Related
I need some general guidelines on how to structure a backbone/marionette application. Im very new to these frameworks and also to js in general.
Basically I have two pages and each page has a list. I have set up an application and a router for the application:
var app = new Backbone.Marionette.Application();
app.module('Router', function(module, App, Backbone, Marionette, $, _){
module.AppLayoutView = Marionette.Layout.extend({
tagName: 'div',
id: 'AppLayoutView',
template: 'layout.html',
regions: {
'contentRegion' : '.main'
},
initialize: function() {
this.initRouter();
},
...
});
module.addInitializer(function() {
var layout = new module.AppLayoutView();
app.appRegion.show(layout);
});
});
In the initRouter I have two functions, one for each page that gets called by router depending on the url.
The function for the content management page looks like this:
onCMNavigated: function(id) {
var cMModule = App.module("com");
var cM = new cMModule.ContentManagement({id: id, region: this.contentRegion});
contentManagement.show();
this.$el.find('.nav-item.active').removeClass('active');
this.cM.addClass('active');
}
So if this is called, I create a new instance of ContentManagement model. In this model, when show() is called, I fetch the data from a rest api, and I parse out an array of banners that need to be shown in a list view. Is that ok? The model looks like the following:
cm.ContentManagement = Backbone.Model.extend({
initialize: function (options) {
this.id = options.id;
this.region = options.region;
},
show: function() {
var dSPage = new DSPage({id: this.id});
dSPage.bind('change', function (model, response) {
var view = new cm.ContentManagementLayoutView();
this.region.show(view);
}, this);
dSPage.fetch({
success: function(model, response) {
// Parse list of banners and for each create a banner model
}
}
});
cm.ContentManagementLayoutView = Marionette.Layout.extend({
tagName: 'div',
id: 'CMLayoutView',
className: 'contentLayout',
template: 'contentmanagement.html',
regions: {
'contentRegion' : '#banner-list'
}
});
Now my biggest doubt is how do I go on from here to show the banner list? I have created a collectionview and item view for the banner list, but is this program structure correct?
do You really need marionnete to manage your application ? especially You are beginner as me too :)
try pure backbone first. You can still use marionette as a library.
backbone MVC architecture is described perfectly on many sites.
Considering something similar to the example outlined here:
App.Router.map(function() {
this.resource("posts", function() {
this.resource("post", { path: "/posts/:post_id" }, function() {
this.resource("comments", { path: "/comments" });
});
});
});
using the DS.RESTAdapter. The Router would load all the posts when I access the PostsRoute with a call to the API URL /posts.
When I then access PostRoute, for example for the post with id=1, it doesn't hit the API again, i.e. it doesn't hit /post/1. It loads the post from the store.
I want then to access CommentsRoute for post with id=1. How do I load the comments?
Should I have sideloaded all the comments in the first place, when I loaded the post list? In this case though, I would need to load all the comments for all the posts. Is it possible to load the comments only when needed, i.e. when I access CommentsRoute?
In this case, how do I actually load the comments from the backend?
Specifically, how do I write the CommentsRoute to load the comments from the RESTful API when I access the page that actually displays them?
I guess one needs to have the following:
App.Post = DS.Model.extend({
comments: DS.hasMany('comment')
});
App.Comment = DS.Model.extend({
post: DS.belongsTo('post')
});
App.CommentsRoute = Ember.Route.extend({
model: function() {
/*
* How do I inject params.post_id here
* to make a request to the RESTful API?
* Which URL would be called?
* /comments?post_id=ID
* /post/post_id/comments
* ...
*/
// Doesn't work, hits /comments
return this.store.find('comment', { post_id: params.post_id });
}
});
Why does
return this.store.find('comment', { post_id: params.post_id });
hit /comments?
You just need to declare your CommentsRoute like this:
App.CommentsRoute = Ember.Route.extend({
model: function() {
return this.modelFor('post').get('comments');
}
});
What it does is, it gets the model of the PostRoute and fetches its comments.
Ember-data handles the logic behind it. If comments were sideloaded, it will just return these. Otherwise it will issue a GET request to fetch them.
For this to work, you need to include the links property on a serialized post. The links property needs to include the URL you wish ember-data to use in order to fetch the comments.
E.g. your serialized post may look like this:
{
"post": {
"id": 1,
"title": "Rails is omakase",
"links": { "comments": "/posts/1/comments" }
}
}
See DS.RESTAdapter#findHasMany.
The hasMany relationship probably needs to be declared async for this to work properly:
App.Post = DS.Model.extend({
comments: DS.hasMany('comment', { async: true })
});
You can use Ember's sideloaded relationships to make the posts API endpoint also return the relevant comments and Ember will figure it out.
http://emberjs.com/guides/models/the-rest-adapter/#toc_sideloaded-relationships
{
"post": {
"id": 1,
"title": "Node is not omakase",
"comments": [1, 2, 3]
},
"comments": [{
"id": 1,
"body": "But is it _lightweight_ omakase?"
},
{
"id": 2,
"body": "I for one welcome our new omakase overlords"
},
{
"id": 3,
"body": "Put me on the fast track to a delicious dinner"
}]
}
You'd then be able to pass the already loaded comments to the comments route.
It may be in the docs but it's quite a specific term! Some of the concepts like that can be a bit tricky to search for.
The following forces a call to the backend /comments?post_id=ID
App.CommentsController = Ember.ArrayController.extend({
needs: 'post'
});
App.CommentsRoute = Ember.Route.extend({
model: function(params) {
return this.store.find('comment', { post_id: this.modelFor('post').get('id') });
}
});
I've got a JSON file that looks like this.
{
"config": {
"setting1": 'blabla',
"setting2": 'blablabla'
},
"content": {
"title": "Title of an exercise.",
"author": "John Doe",
"describtion": "Exercise content."
},
"answers": [
{
"id": "1",
"content": "Dog",
"correct": true
},
{
"id": "2",
"content": "Fish",
"correct": false
}
]
}
Than, I create a Backbone View, combined from content model, and answers (which are randomly selected, but It's not most important now).
I've also got a config, which has settings that will determinate which view and collection methods to use.
It seems like a simple task, but as I'm new to Backbone, I'm wondering which is the best way to fetch JSON file, creating one model with url to JSON and than using parse and initialize creating another models and collections (with answers), or using $.getJSON method that will create exactly the models that I need?
I was trying using $.getJSON
$.getJSON(source, function(data) {
var contentModel = new ContentModel(data.content);
var contentView = new ExerciseView({ model: contentModel });
var answerCollection = new AnswersCollection();
_.each(data.answers, function(answer) {
answerCollection.add(answer);
});
var answersView = new AnswersView({collection: answerCollection});
$(destination).html( contentView.render().el );
$('.answers').append( answersView.el );
)};
But It doesn't seem very elegant solution, I know that this application needs good architecture, cause It will be developed with many other Views based on 'config'.
Hope you guys give me some suggestions, have a good day!
I think what you've done works fine and is correct. But you may need to refactor a little bit since "it will be developed with many other Views based on 'config'".
IMHO, the first thing you need to do is to handle failure in your getJson callback to make the process more robust.
Second, it is useful to create a Factory to generate your views because your logic is to generate different views based on the config data from server. So the factory maybe:
contentViewFactory.generate = function(data) {
var config = data.config;
....
var ActualContentView = SomeContentView;
var contentModel = new ContentModel(data.content);
return = new ActualContentView({ model: contentModel });
}
If your logic is simple, you can have a dict map from config to view class like:
var viewMaps = {
"exercise" : ExerciseView,
"other": SomeOtherView,
//....
}
And if every workflow has a AnswersView you can keep that in your getJSON callback. So maybe now your getJSON looks like this:
$.getJSON(source, function(data) {
// keep the config->view logic in the factory
var contentView = contentViewFactory.generate(data);
var answerCollection = new AnswersCollection();
_.each(data.answers, function(answer) {
answerCollection.add(answer);
});
var answersView = new AnswersView({collection: answerCollection});
$(destination).html( contentView.render().el );
$('.answers').append( answersView.el );
})
.fail(){
//some failure handling
};
Furthermore, if you have common logics in you "ContentView"s, it's natural that you can have a "BaseContentView" or "ContentViewMixin" to extract the common logic and use extends to make your code more OO:
Backbone.View.extend(_.extend({}, ContentViewMixin, {
//.....
}
So if someone is trying to add a new ContentView, he/she just needs to add some code in the factory to make the new View be generated by config. Then extends the ContentViewMixin to implement the new View.
I am using Ember.js with local-storage-adapter. I have a weird problem while updating records.
I have a post and comments model with hasMany relationships:
App.Post = DS.Model.extend({
title: DS.attr('string'),
comments: DS.hasMany('comment', {
async: true
})
});
App.Comment = DS.Model.extend({
message: DS.attr('string')
});
These are my post and comments controllers:
App.PostsController = Ember.ArrayController.extend({
newTitle: '',
actions: {
create: function() {
var title = this.get('newTitle');
var post = this.store.createRecord('post', {
title: title
});
this.set('newTitle', '');
post.save();
}
}
});
App.CommentsController = Ember.ArrayController.extend({
needs: "post",
post: Ember.computed.alias("controllers.post.model"),
newMessage: '',
actions: {
create: function() {
var message = this.get('newMessage');
var comment = this.store.createRecord('comment', {
message: message
});
var post = this.get('post');
var comments = post.get('comments');
if (comments.get('content') == null) comments.set('content', []);
comments.pushObject(comment);
comment.save();
post.save();
}
}
});
While creating records hasMany relations updated correctly.
{
"App.Post": {
"records": {
"0v66j": {
"id": "0v66j",
"title": "post1",
"comments": ["p31al", "tgjtj"]
}
}
},
"App.Comment": {
"records": {
"p31al": {
"id": "p31al",
"message": "comment 1"
},
"tgjtj": {
"id": "tgjtj",
"message": "comment 2"
}
}
}
}
The problem occured while editing post. The relationships are gone after editing the post record. I did some searching and found this code:
DS.JSONSerializer.reopen({
serializeHasMany: function(record, json, relationship) {
var key = relationship.key;
var relationshipType = DS.RelationshipChange.determineRelationshipType(record.constructor, relationship);
// alert(relationshipType);
if (relationshipType === 'manyToNone' || relationshipType === 'manyToMany' || relationshipType === 'manyToOne') {
json[key] = Ember.get(record, key).mapBy('id');
// TODO support for polymorphic manyToNone and manyToMany
// relationships
}
}
});
This did the trick and it worked fine. But now I have another problem. If I edit any other record, all the id references are replaced by whole object like this:
{"App.Post":{"records":{"0v66j":{"id":"0v66j","title":"post2","comments":[**{"message":"comment 1"},
{"message":"comment 2"}**]},"8nihs":{"id":"8nihs","title":"post3","comments":["b4v2b","dbki4"]}}},
"App.Comment":{"records":{"p31al":{"id":"p31al","message":"comment 1"},"tgjtj":{"id":"tgjtj","message":"comment 2"},
"b4v2b":{"id":"b4v2b","message":"comments3"},"dbki4":{"id":"dbki4",
"message":"comments4"}}}}
Comment refrences should be comments":["p31al","tgjtj"] like this. but the ids are replaced as "comments":[{"message":"comment 1"},{"message":"comment 2"}]
When using ApplicationSerializer which extends LSSerializer, it seems to work.
Maybe it got fixed since asked?
I've noticed a few things in my path with Ember... and especially Ember-Data.
One of them is when dealing with associations I've had to manually re-add in the associations saving and having to re-save, and use addObject to in-memory associations as you're using a bit here. :)
Note that this usually only happens when I'm updating more than one new object at once. For example, if your post is new, and your comment is also new.
I'm a little worried to see the following code in your codebase, because it shouldn't need to be there. You shouldn't ever have null or non-array objects in your associations. I'm not sure what hackery you did with the Adapter and why it was necessary, but I hope that wasn't the reason:
if(comments.get('content') == null)
comments.set('content', []);
Anyway, the following code is how I would probably write your create action. It might help. I hope it does.
create: function() {
// get the post for association on the new comment
var post = this.get('post');
// get the message to store on the new comment
var message = this.get('newMessage');
var comment = this.store.createRecord('comment', {
message : message,
post : post
});
comment.save().then(function(savedComment) {
post.get('comments').addObject(savedComment);
});
}
Note that it's a lot simpler. Generally if you're doing tricky complicated things, something's amiss and it's time to go back to basics and add one thing at a time, testing thoroughly between additions. :)
Good luck!
I have two backbone models, loaded from server:
var Model = Backbone.Model.extend({});
var SubModel = Backbone.Model.extend({});
var SubCollection = Backbone.Collection.extend({
model: SubModel
});
var m = new Model();
m.fetch({success: function(model)
{
model.submodels = new SubCollection();
model.submodels.url = "/sub/" + model.get("id");
model.submodels.fetch();
}});
So, the server has to send two separate responses. For example:
{ name: "Model1", id: 1 } // For Model fetch
and
[{ name: "Submodel1", id: 1 }, { name: "Submodel2", id: 2 }] // For Submodel collection fetch
Is there a way to fetch a Model instance with Submodel collection at once, like:
{
name: "Model1",
id: 1,
submodels: [{ name: "Submodel1", id: 2 }, { name: "Submodel1", id: 2 }]
}
To be able to do that is up to your back-end - it doesn't really have anything to do with Backbone.
Can you configure your back-end technology to return related models as nested resources?
If your back-end is Rails, for instance, and your models are related in ActiveRecord, one way of doing this is something like
respond_to do |format|
format.json { render :json => #model.to_json(:include => [:submodels])}
end
What back-end technology are you using?
Edit:
Sorry, misunderstood the gist of your question, once you've got your back-end returning the JSON in the proper format, yeah, there are things you need to do in Backbone to be able to handle it.
Backbone-Relational
One way to deal with it is to use Backbone-Relational, a plugin for handling related models.
You define related models through a 'relations' property:
SubModel = Backbone.RelationalModel.extend({});
SubCollection = Backbone.Collection.extend({
model: SubModel
});
Model = Backbone.RelationalModel.extend({
relations: [
{
type: 'HasMany',
key: 'submodels',
relatedModel: 'SubModel',
collectionType: 'SubCollection'
}
]
});
When your Model fetches the JSON, it will automatically create a SubCollection under the 'submodels' property and populate it with SubModels - one for each JSON object in the array.
jsfiddle for backbone-relational: http://jsfiddle.net/4Zx5X/12/
By Hand
You can do this by hand if you want as well. In involves overriding the parse function for your Model class (forgive me if my JS is not 100% correct - been doing CoffeeScript so much lately its hardwired in my brain)
var Model = Backbone.Model.extend({
parse: function(response) {
this.submodels = new SubCollection();
// Populate your submodels with the data from the response.
// Could also use .add() if you wanted events for each one.
this.submodels.reset(response.submodels);
// now that we've handled that data, delete it
delete response.submodels;
// return the rest of the data to be handled by Backbone normally.
return response;
}
});
parse() runs before initialize() and before the attributes hash is set up, so you can't access model.attributes, and model.set() fails, so we have to set the collection as a direct property of the model, and not as a "property" that you would access with get/set.
Depending on what you want to happen on "save()" you may have to override `toJSON' to get your serialized version of the model to look like what your API expects.
jsfiddle:
http://jsfiddle.net/QEdmB/44/