Backbone not parsing JSON correctly - javascript

Overview
I have a JSON object being passed to my backbone model. I have a parse function in the backbone model to convert some of the incoming attributes. The issue is when I fetch this model the attributes are not parsed and are just added to the model. The image at the bottom shows that instead of converting password to Password and deleting password it just adds password to the attributes of the object.
Here is my code:
JSON
When I use postman to call my web service I get the response:
{"type":null,"idTeacher":1,"name":"Sean","password":"tst","email":null,"dob":1392940800000}
Model:
window.Teacher = Backbone.Model.extend({
urlRoot: "http://localhost:8080/SIMS/resource/teacher",
defaults: {
"id": null,
"Name": "",
"Password": "",
"email": "",
"dob": "",
"type": ""
},
parse: function(response){
response.id = response.idTeacher;
response.Password = response.password;
response.Name = response.name;
delete response.name;
delete resoponse.password;
delete response.idTeacher;
return response;
}
});
window.TeacherCollection = Backbone.Collection.extend({
model: Teacher,
url: "http://localhost:8080/SIMS/resource/teacher",
parse: function(response){
return response;
}
});
Main.js // This is
before: function(callback) {
if (this.teacherList) {
if (callback) callback();
} else {
console.log('........................................javascript........');
this.teacherList = new TeacherCollection();
console.log('Loading List: Size: ' + this.teacherList.length);
this.teacherList.fetch({success: function() {
console.log('........... ftech success...........');
$('#contents').html( new TeacherListView({model: app.teacherList}).render().el );
if (callback) callback();
}});
}
}
If I debug my Backbone I can see that my parse did not parse any of the variable and the delete calls in the parse did not work either.
UDATE ANSWER
Thanks for the help. The fact that I hadn't the code in the collection class was an issue. But the second reason was that I wasn't looping through the collection to change each of the attributes.

That's because when you call the fetch method for your collection, the parse method that is called is the parse of the collection and not the parse of your teacher model.
When you call the fetch method from the collection the collections expects to receive an array of models and not just one teacher as you described

You are defining your parse method in your Model but calling your Collection fetch method.
In this case, only the parse method of your Collection will be called.

Related

Associating xxxx_id with xxxx.id

I am running into a problem where when I submit a "property listing" I get this response:
{"owner_id":"Batman","address":"test","state":"test","sale_price":"test"}
The thing is "owner_id" is supposed to equal or associate with owner's id in a different table/JSON file (e.g owner_id = owner.id), not a string in this case which is why the object is not saving on the back-end.
Is anyone in vanilla JavaScript able to show me an example on how to associate owner_id and owner.id?
It'd be more like :
{
owner: {
id: "Batman"
},
address: "test",
state: "test",
sale_price: "test"
}
You should take a look at : https://www.w3schools.com/js/js_json_objects.asp
EDIT: Not sure how you're fetching this data but it seems like you want to handle the response you're getting.
Here is a simple GET request using the fetch api:
fetch('http://example.com/heroes') //this is the path to your source where you're getting your response data
.then((response) => {
return response.json();
//above you return a promise containing your response data
//you can also handle your response before declaring it in a var here
})
.then((myJson) => {
//you have stored your response data as a var myJson
console.log(myJson);
//here you can work your response data in any way you need
// to show an example (not that you would do this) I've provided a owner object that checks if it's property is equal to the incoming data
var owner = {
"id": Batman,
}
if ( myJson.owner_id === owner.id ) {
//do something here
}
});
More info here.

Populate Backbone.js JSON response into nested collections inside nested collections/models

My problem is that I am just starting out with Backbone.js and are having trouble wrapping my head around a complex problem. I want to save a form that have infinite fields, and some of the fields also needs to have infinite options. I'm just worried I might have started at the wrong end with a JSON response, instead of building the models/collections first. Here is a short pseudocode of what I try to achieve.
id:
parent: <blockid>
fields: array(
id:
title:
helpertext
options: array(
id:
type:
value:
)
)
Currently I am working with a faked JSON response from the server, which I built from scratch, and now I want to divide it into models and collections on the client side.
//Fake a server response
var JSONresponse = {
"formid":"1",
"fields":[
{
"fieldid":"1",
"title":"Empty title",
"helper":"Helper text",
"type":"radio",
"options":[
{
"optionid":"1",
"value":"Empty option.."
},
{
"optionid":"2",
"value":"Empty option.."
}
]
},
{
// fieldid2
}
]
};
The idea is to add fields as I see fit, and then if the field type is radio/checkbox/ul/ol there must also be an "options" array within the field.
My work so far:
var app = {};
app.Models = {};
app.Collections = {};
app.View = {};
app.Models.Option = Backbone.Model.extend({
});
app.Collections.Options = Backbone.Collection.extend({
model: app.Models.Option
});
app.Models.Field = Backbone.Model.extend({
options: new app.Collections.Options()
});
app.Collections.Fields = Backbone.Collection.extend({
model: app.Models.Field
});
app.Models.Form = Backbone.Model.extend({
formid : "1",
fields: new app.Collections.Fields(),
initialize: function() {
}
});
How do I split up my JSON response into all these models and collections?
(Perhaps I should re-evaluate my approach, and go for something like form.fieldList and form.optionList[fieldListId] instead. If so, how would that look like?)
Edit: Here is a little jsfiddle after many fixes, but I still don't really know how to make the inner options list work.
The easiest solution would be using Backbone Relational or Backbone Associations.
The documentation should be enough to help you get started.
If you don't want to use a library you could override the parse function on the Form model.
app.Models.Form = Backbone.Model.extend({
defaults: {
fields: new app.Collections.Fields()
},
parse: function(response, options) {
return {
formid: response.formid,
fields: new app.Collections.Fields(_.map(response.fields, function(field) {
if (field.options) {
field.options = new app.Collections.Options(field.options);
}
return field;
}))
};
}
});
Now if you fetch a form from the server, the response will be parsed into an object graph of models and collections.
form.get('fields') will return an app.Collections.Fields collection. form.get('fields').first().get('options') will return an app.Collections.Options collection, if any options exist.
Also, you could create the form model like this:
var form = new app.Models.Form(JSONresponse, {
parse: true
});
This would result in the same object structure.
It's quite hard to handle the case of nested models and collections right in plain Backbone.
Easiest way of handling this will be something like this:
var Option = Nested.Model.extend({
idAttribute : 'optionid',
defaults : {
optionid : Integer
value : ""
}
});
var Field = Nested.Model.extend({
idAttribute : 'fieldid',
defaults : {
fieldid : Integer,
title : "",
helper : "",
type : "radio",
options : Option.Collection
}
});
var Form = Nested.Model.extend({
idAttribute : 'formid',
defaults : {
formid: Integer,
fields: Field.Collection
});
https://github.com/Volicon/backbone.nestedTypes
And that's it. Yep, you'll get direct access to the attributes as free bonus, just form.fields.first().options.first().value, without that get and set garbage.

Backbone save with LocalStorage with fetched DB data?

UPDATE
Ok, so I am still getting into the world of Backbone. But I have an issue with adding in localStorage into the Model.
So this is sorta off working, but I do not know what is going on?
var Model = Backbone.Model.extend({
//localStorage: new Backbone.LocalStorage("SomeCollection"),
url: "/GetMyData",
defaults: {
"id": "",
"datatest1": "",
"test2": ""
}
});
var NewTest = new Model();
NewTest.fetch();
console.log ( NewTest ); //This as DB data
console.log ( NewTest.attributes ); //This is empty
How can the 'attributes' on the 1st console.log contain db data and then the second one be completely empty? The 1st console.log is also empty, if I uncomment the localStorage, so I am guesting I doing something wrong?
Ok, I am not sure what I am doing wrong, but I am using Backbone and on a fetch call, save that id using the LocalStorage plugin. Now I have the fetch call and LocalStorage working apart but can not get them working together.
So my LocalStorage Code
var Model = Backbone.Model.extend({
localStorage: new Backbone.LocalStorage("SomeCollection"),
defaults: {
"id": "",
"datatest1": "",
"test2": ""
}
});
var NewTest2 = new Model();
NewTest2.set({
"id": "99",
"datatest1": "TEST-1-Q22",
"test2": "TEST-2-CL22"
});
NewTest2.save();
So this works, no problems with that. Now I add in a collection, and fetch data form my database. So my fetch code, with collection
var Model = Backbone.Model.extend({
defaults: {
"id": "",
"datatest1": "",
"test2": ""
}
});
var Col = Backbone.Collection.extend({
model: Model,
url: "/GetMyData"
});
var NewTest3 = new Col();
NewTest3.fetch();
console.log( NewTest3 );
I should also say that I am using PHP Slim as the base. The /GetMyData path gets the data from a MySQL database via a PDO connection, which I then convert into a JSON object for Backbone.
Which I assume is good, as that all works, the console.log's list of attributes displays the right data form my DB.
Now when I put the two together, I can not seem to get it to work.
var Model = Backbone.Model.extend({
defaults: {
"id": "",
"datatest1": "",
"test2": ""
}
});
var Col = Backbone.Collection.extend({
localStorage: new Backbone.LocalStorage("SomeCollection2"),
model: Model,
url: "/GetMyData"
});
var NewTest4 = new Col();
NewTest4.fetch();
console.log( NewTest4.save() );
This console.log returns, Uncaught TypeError: undefined is not a function. So I am not sure why? When I set the data in my 1st test, it works fine. Now I have also tried moving the localStorge var into the model but with the same effect.
The main aim for doing this is so I can log all the data coming from the server. When I set a few different data tests, I very much like the way in which this plugin saved the data.
Thanks.
*Please note, I am dyslexic, so I may not have explained myself right, please tell me if there is anything I can re-word to explain myself better. Thank you for your understanding.

backbone populate collection from external json

Below is the current code structure I have in place for a collection that I have manually constructed. I have a json file on my server which I am now trying to load in and basically remove the manual one and construct a collection based on that data. Was wondering what would I possibly need to change below to my code to help accommodate this.
var Game = Backbone.Model.extend({
defaults: {
name: 'John Doe',
age: 30,
occupation: 'worker'
}
});
var GameCollection = Backbone.Collection.extend({
model: Game,
url: 'path/to/json',
parse: function(response) {
return response;
}
});
var GamesView = Backbone.View.extend({
tagName: 'ul',
render: function() {
//filter through all items in a collection
this.collection.each(function(game){
var gameView = new GameView({model: game});
this.$el.append(gameView.render().el);
}, this)
return this;
}
});
var GameView = Backbone.View.extend({
tagName: 'li',
template: _.template($('#gameTemplate').html()),
render: function() {
this.$el.html(this.template(this.model.toJSON()));
return this;
}
});
var gameCollection = new GameCollection([
{
name: 'John Doe',
age: 30,
occupation: 'worker'
},
{
name: 'John Doe',
age: 30,
occupation: 'worker'
},
{
name: 'John Doe',
age: 30,
occupation: 'worker'
}
]);
var gamesView = new GamesView({collection: gameCollection});
$(document.body).append(gamesView.render().el);
This is one of the many things to love about Backbone. I don't know what you are using for your backend, but you state that you have a json file on your server, hopefully a json file full of the models that should be in your collection. And now here is the magic code (drumroll please..):
var GameCollection = Backbone.Collection.extend({
model: Game,
url: 'path/to/json/on/external/server',
});
var gameCollection = new GameCollection();
gameCollection.fetch();
Not much to it, right? Of course there are several options you can add or change to a fetch, so check out the docs here: http://backbonejs.org/#Collection-fetch. Backbone uses jQuery.ajax() be default, so check out the docs here to see all of the options: http://api.jquery.com/jQuery.ajax/
You shouldn't need the custom parse in your collection unless your models on the server don't match your backbone models.
Things to know:
fetch is asynchronous. It takes time to talk to the server, and the rest of your javascript will move on and complete. You will probably need to at least add a callback function to the success option, which will be called when fetch is finished, and it is good to add something to error as well, in case something goes wrong. You can add data as a query string so that your backend can use it using the data option, the data has to be an object. Here is an example:
gameCollection.fetch({
data: {collection_id: 25},
success: function(){
renderCollection(); // some callback to do stuff with the collection you made
},
error: function(){
alert("Oh noes! Something went wrong!")
}
});
fetch should receive data as JSON, so your url should either exclusive return JSON or be set up to detect an AJAX request and respond to it with JSON.
Firstly you need to fetch it from server as RustyToms said. And the other consideration is how to force the collection view to render itself again once data collected from server, as muistooshort commented.
If you manipulating fetch or sync you'll need to do it multiple times when there are more than one collection in app.
Doing such is native with Marionette, but in plain Backbone you can mimic the method of Marionette's CollectionView and do such:
//For the collection view
var GamesView = Backbone.View.extend({
initialize: function({
this.listenTo(this.collection, 'reset', this.render, this);
});
// Others
});
Then, when collection data fetched from server, the collection will trigger a reset event, the collection view noticed this event and render itself again.
For more than one collections, you can extract the code into a parent object in app and inherit from that.
var App.CollectionView = Backbone.View.extent({
initialize: //code as above
});
var GamesView = App.CollectionView.extend({
//Your code without initialize
});
I know this is a bit old at this point, but wanted to answer for anyone else stuck on this.
The code seems to come from the tutorial found here: http://codebeerstartups.com/2012/12/a-complete-guide-for-learning-backbone-js/
I too re-purposed the demo app found in that tutorial and had trouble rendering using external data.
The first thing is that the data itself needs to be converted to valid JSON or else you'll get a .parse() error.
SyntaxError: JSON.parse: expected property name or '}' at line 3 column 9 of the JSON data
or
error: SyntaxError: Unexpected token n
In your data source file, object properties need to be surrounded by quotes. It should look something like this:
[
{
"name": "John Doe",
"age": 30,
"occupation": "worker"
},
{
"name": "John Doe",
"age": 30,
"occupation": "worker"
},
{
"name": "John Doe",
"age": 30,
"occupation": "worker"
}
]
Secondly, once it's clear the external data is loading, we need to get it to render. I solved this (perhaps ungracefully) by moving the render() command into the success function of your gameCollection.fetch().
gameCollection.fetch({
success: function(collection, response, options) {
console.log('Success!! Yay!!');
$(document.body).append(gamesView.render().el);
},
error: function(collection, response, options) {
console.log('Oh, no!');
// Display some errors that might be useful
console.error('gameCollection.fetch error: ', options.errorThrown);
}
});
There are certainly better ways to accomplish this, but this method directly converts the code learned in the tutorial into something that works with external data.

Ember data 1.0 beta how map embedded data

It seems that ember data have many changing up to version 1.0 beta. All works great with version 0.13. now I want update to higher version. In my case we have an embedded model 'user'
App.Post = DS.Model.extend({
subject: DS.attr('string'),
created: DS.attr('number'),
fcreated: function(){
debugger;
var d = new Date(this.get('created'));
return d.toLocaleDateString();
}.property('created'),
reporter: DS.belongsTo('user')
}
App.ApplicationAdapter = DS.RESTAdapter.extend({
namespace: 'restws'
});
The Json from server looks like this.
{
"posts": [
{
"id": "5226f2670364e70ae7d77266",
"subject": "Text",
"created": 1325410935048,
"reporter": {
"id": "5226f2660364e70ae7d771e2",
"firstName": "Doris",
"lastName": "Baumertr"
}
}
I get the following error code 'Uncaught TypeError: Cannot call method 'toString' of undefined'. In the ember source code I see, that in ember-data.js line 2236 the function throw the error 'buildRecord: function(type, id, data) .. ' After debugging I see that the properties type is undefined id is set with the correct id and data is undefined?
What is the mistake? How I can map the embedded data?
Here's actually the exact extractSingle method that you need to implement
App.PostSerializer = DS.RESTSerializer.extend({
extractSingle: function(store, type, payload, id, requestType) {
if(typeof payload.post.reporter !== "undefined") {
var reporter_id = payload.post.reporter.id;
payload.users = [payload.post.reporter];
payload.post.reporter = reporter_id;
}
return this._super.apply(this, arguments);
}
});
Here's a jsbin http://jsbin.com/EKItexU/1/edit?html,js,output
Note, that I had to redefine ajax method in RESTAdapter to emulate the server returning your JSON.
Also, if you are sideloading users in your JSON, than you'll have to update this method so it doesn't overwrite sideloaded users in your payload (payload.users property)
Support for embedded records is gone (for now).
You can handle embedded records yourself by implementing extractSingle and reorganizing your JSON payload.
Please read here for more info about the transition: https://github.com/emberjs/data/blob/master/TRANSITION.md#embedded-records
Hope it helps.

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