I am new to backbone and nodejs, I have made a demo which used backbone and nodejs for updating and inserting data. I'm able to send put request with single data at a time.
this.model.set({
user_id:Session.get('userid'),
seat_id:seatId
});
this.model.save({
success: function() {
// do some stuff here
alert("a")
},
error: function() {
// do other stuff here
alert("b")
}
})
The above code post single row info to server. I want to send multiple info to server at a time. Can we set model something like below
this.model.set([{
user_id:Session.get('userid'),
seat_id:2
},{
user_id:Session.get('userid'),
seat_id:3
}]);
Thanks
You can do that:
arr = [{
user_id:Session.get('userid'),
seat_id:2
},{
user_id:Session.get('userid'),
seat_id:3
}];
this.model.set(sessions, arr);
Related
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'm trying to get a handle on using $resource in angularjs and I keep referencing this answer AngularJS $resource RESTful example for good examples. Fetching a record and creating a record work fine, but now i'm trying to add a "section" to an existing mongo record but can't figure it out.
documents collection
{
_id: 'theid',
name: 'My name",
sections: [
{
title: 'First title'
},
{
title: 'Second title'
}
]
}
angular controller snippet
var document = documentService.get({_id: 'theid'});
// TRYING TO ADD $scope.section TO THE SECTIONS ARRAY IN THE VARIABLE document.
//document.sections.push($scope.section); <-- This does NOT work
//document.new_section($scope.section); <-- could do this and then parse it out and insert it in my backend code, but this solution seems hacky and terrible to me.
document.$save(function(section) {
//$scope.document.push(section);
});
documentService
return $resource(SETTINGS.base + '/documents/:id', { id: '#id' },
{
update: { method: 'PUT' }
});
From the link i posted above, If I was just updating the name field, I could just do something like this:
var document = documentService.get({_id: 'theid'});
document.name = "My new name";
document.$save(function(section) {
//$scope.document.push(section);
});
I'm just trying to add an object to a nested array of objects.
Try this:
documentService.get({_id: 'theid'}, function(document) {
document.sections.push($scope.section);
document.$save();
});
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/
I'm trying to load some data into a Backbone Collection from a local JSON file, using this very basic code:
window.Student = Backbone.Model.extend({
});
window.Students = Backbone.Collection.extend({
model: Student,
});
window.AllStudents = new Students();
AllStudents.fetch({ url: "/init.json"});
console.log('AllStudents', AllStudents);
In the console statement, AllStudents is empty. But init.json is definitely being loaded. It looks like this:
[
{ text: "Amy", grade: 5 },
{ text: "Angeline", grade: 26 },
{ text: "Anna", grade: 55 }
]
What am I doing wrong?
UPDATE: I've also tried adding a reset listener above the .fetch() call, but that's not firing either:
AllStudents.bind("reset", function() {
alert('hello world');
});
AllStudents.fetch({ url: "/init.json"});
No alert appears.
UPDATE 2: Trying this script (reproduced here in full):
$(function(){
window.Student = Backbone.Model.extend({
});
window.Students = Backbone.Collection.extend({
model: Student,
});
window.AllStudents = new Students();
AllStudents.url = "/init.json";
AllStudents.bind('reset', function() {
console.log('hello world');
});
AllStudents.fetch();
AllStudents.fetch({ url: "/init.json", success: function() {
console.log(AllStudents);
}});
AllStudents.fetch({ url: "/init.json" }).complete(function() {
console.log(AllStudents);
});
});
Only one console statement even appears, in the third fetch() call, and it's an empty object.
I'm now absolutely baffled. What am I doing wrong?
The JSON file is being served as application/json, so it's nothing to do with that.
The attribute names and non-numeric attribute values in your JSON file must be double quoted (" ") . Single quotes or no-quotes produces errors and response object is not created that could be used to create the models and populate the collection.
So. If you change the json file content to :
[
{ "text": "Amy", grade: 5 },
{ "text": "Angeline", grade: 26 },
{ "text": "Anna", grade: 55 }
]
you should see the non-empty collection object.
You can change your code to see both success and failure as below:
AllStudents.fetch({
url: "/init.json",
success: function() {
console.log("JSON file load was successful", AllStudents);
},
error: function(){
console.log('There was some error in loading and processing the JSON file');
}
});
For more details, probably it will be a good idea to look in to the way ajax response objects are created.
I/O operations in javascript are almost always asynchronous, and so it is with Backbone as well. That means that just because AllStudents.fetch has returned, it hasn't fetched the data yet. So when you hit your console.log statement, the resources has not yet been fetched. You should pass a callback to fetch:
AllStudents.fetch({ url: "/init.json", success: function() {
console.log(AllStudents);
}});
Or optionally, use the new promise feature in jQuery (fetch will return a promise):
AllStudents.fetch({ url: "/init.json" }).complete(function() {
console.log(AllStudents);
});
fetch() returns a 'success' notification as already stated, but that just means that the server request was successful. fetch() brought back some JSON, but it still needs to stuff it into the collection.
The collection fires a 'reset' event when it's contents have been updated. That is when the collection is ready to use...
AllStudents.bind('reset', function () { alert('AllStudents bind event fired.'); });
It looks like you had this in your first update. The only thing I did differently was to put fetch() in front of the event binding.
I think you need to add {add:true} to the options of fetch,
if you assigned the fetch to a variable, you would get the result as well,
but then its not inside the collection you wanted
Have checked some backbone.js tutorials and can't
understand how to get model id from the server within
the model saving process. I have a model:
var Game = Backbone.Model.extend({
defaults: {
name: '',
releaseDate: ''
},
url: function(){
return '/data.php';
}
});
How to implement getting the id algorithm? It seams to me, there should
be a kind of callback function, but can't realise where to put it.
See Backbone's documentation on model save.
You can pass a success callback function to save, something like this:
var game = new Game({
name: 'Duke Nukem 3D',
releaseDate: '1996'
});
game.save({}, {
success: function(model, response) {
// get model id from response?
}
);