Backbone select not work - backbone.js

I'm using select function but returns empty value.I need to get only models with attribute tipo = value
var Integrated = Backbone.Collection.extend({
equalThan: function (value) {
var models = this.select(function (model) {
return model.get(tipo) === value;
});
console.log(models);//empty
},
})
tipo is attribute name, and value is attribute value

Related

Get properties of a Backbone model starting with certain text using Underscore.js

I have a Backbone Model in which there are certain properties like
test_id
test_name
test_desc
test_score
Now I want to retrieve properties which are starting with "test_".
I tried with code below and its working fine.
var MyModel = Backbone.Model.extend({
getTestProperties: function(str){
// get clone of attributes to iterate over
var testProperties = {};
var attrs = _.clone(this.attributes);
_.each(attrs, function(val, key){
if(key.indexOf(str) == 0){
testProperties[key]= val;
}
}, this);
}
});
But
Is there any other way I can get these properties using underscore methods ?
Thanks
Backbone proxies some methods from Underscore on models that can help you create a more readable _.filter: _.keys and _.pick
You can then simplify your function like this :
var MyModel = Backbone.Model.extend({
getTestProperties: function (str) {
// get the keys you want
var keys = _.filter(this.keys(), function (key) {
return key.indexOf(str) === 0;
});
// and build an object
return this.pick(keys);
}
});
And a demo http://jsfiddle.net/nikoshr/5a63c/
Try something like
var attrs = _.filter(_.keys(_.clone(this.attributes)), function(attr){
return attr.indexOf("text_") === 0;
});

Backbone custom model get

I'd like one of my getters to return a minimum value of the model's collection, is it possible to have a model getter function? Reason I need this is so I can easily have my models rendered in a template using toJSON.
Are these minimum values just defaults to fill in, if there is nothing else?
If so. you can define the defaults on the model
var model = Backbone.Model.extend({
defaults: {
attrA: 'attr a default',
attrB: 'attr b default'
}
});
Apart from the defaults you can override the get method if you need more control.
var MyModel = Backbone.Model.extend({
get: function (attr) {
if (attr === 'my_attribute')
{
return this.getMyAttribute();
}
return Backbone.Model.prototype.get.call(this, attr);
},
getMyAttribute: function() {
var result = Backbone.Model.prototype.get.call(this, attr);
if (typeof result === "undefined" || result < 0) return 0;
return result;
}
});

How to test for undefined Object properties in handlebar.js

i have a collection with models with a property called start_time in seconds (0-60..), which is undefined if no start_time is set.
i have troubles to test if this property is 0 or null/undefined, since the handlebar #if always converts it to 0
If you are fetching the data you could use collection.parse to set a new field on the model that you could test for in your view.
YourCollection = Backbone.Collection.extend({
url: "/api/foo",
parse: function(res) {
return _.map(res, function(source) {
obj = _.clone(source);
obj.no_start = !obj.hasOwnProperty('start_time');
return obj;
});
}
});
Why not just use backbone model defaults?
YourModel = Backbone.Model.extend({
defaults : {
start_time = 'no start time'
}
});
The string should evaluate to true and any null or undefined value will be set to 'no start time' when your model is initialized.
You could do a little bit of work before calling your template: make start_time a string ('0' is true).
You could also register a helper: see boolean logic within a handlebars template.
Should give something like:
Handlebars.registerHelper('if_all', function() {
var args = [].slice.apply(arguments);
var opts = args.pop();
var fn = opts.fn;
if(!args[0] && args[0] != 0) fn = opts.inverse;
return fn(this);
});

passing data to a collection in backbone

So I am trying storing product types from a json file before trying to add them to a collection but am getting some strange results (as in I dont fully understand)
on my router page i setup a variable for cached products as well as product types
cachedProductTypes: null,
productType : {},
products : {},
getProductTypes:
function(callback)
{
if (this.cachedProductTypes !== null) {
return callback(cachedProductTypes);
}
var self = this;
$.getJSON('data/product.json',
function(data)
{
self.cachedProductTypes = data;
callback(data);
}
);
},
parseResponse : function(data) {
result = { prodTypes: [], products: [] };
var type;
var types = data.data.productTypeList;
var product;
var i = types.length;
while (type = types[--i]) {
result.prodTypes.push({
id: type.id,
name: type.name,
longName: type.longName
// etc.
});
while (product = type.productList.pop()) {
product.productTypeId = type.id,
result.products.push(product);
}
};
this.productType = result.prodTypes;
console.log( "dan");
this.products = result.products;
},
showProductTypes:function(){
var self = this;
this.getProductTypes(
function(data)
{
self.parseResponse(data);
var productTypesArray = self.productType;
var productList=new ProductsType(productTypesArray);
var productListView=new ProductListView({collection:productList});
productListView.bind('renderCompleted:ProductsType',self.changePage,self);
productListView.update();
}
);
}
when a user goes to the show product types page it runs the showProductsType function
So I am passing the products type array to my collection
on the collection page
var ProductsType=Backbone.Collection.extend({
model:ProductType,
fetch:function(){
var self=this;
var tmpItem;
//fetch the data using ajax
$.each(this.productTypesArray, function(i,prodType){
tmpItem=new ProductType({id:prodType.id, name:prodType.name, longName:prodType.longName});
console.log(prodType.name);
self.add(tmpItem);
});
self.trigger("fetchCompleted:ProductsType");
}
});
return ProductsType;
now this doesnt work as it this.productTypesArray is undefined if i console.log it.
(how am I supposed to get this?)
I would have thought I need to go through and add each new ProductType.
the strange bit - if I just have the code
var ProductsType=Backbone.Collection.extend({
model:ProductType,
fetch:function(){
var self=this;
var tmpItem;
//fetch the data using ajax
self.trigger("fetchCompleted:ProductsType");
}
});
return ProductsType;
it actually adds the products to the collection? I guess this means I can just pass an array to the collection and do not have to add each productType?
I guess this means I can just pass an array to the collection and do not have to add each productType?
Yes, you can pass an array to the collection's constructor, and it will create the models for you.
As far as your caching code, it looks like the problem is here:
if (this.cachedProductTypes !== null) {
return callback(cachedProductTypes);
}
The callback statement's argument is missing this - should be return callback(this.cachedProductTypes).

How to show data stored in local storage in my table

I am creating a contact Manager using backbone.js,this is my code
$(document).ready(function() {
var Contact=Backbone.Model.extend({
defaults: {
fname : '',
lname : '',
phoneno : ''
}
});
var ContactList=Backbone.Collection.extend({
model : Contact,
localStorage: new Store("ContactList-backbone")
});
var ContactView=Backbone.View.extend({
el : $('div#contactmanager'),
events: {
'click #additems' : 'add'
},
initialize: function() {
this.render();
this.collection = new ContactList();
},
add : function() {
s1=$('#fname').val();
s2=$('#lname').val();
s3=$('#phoneno').val();
if(s1 =="" || s2=="" || s3=="")
{
alert("Enter values in Textfield");
}
else
{
$('#tlist').append("<tr><td>"+s1+"</td><td>"+s2+"</td><td>"+s3+"</td> </tr>");
cont=new Contact({fname:s1,lname:s2,phoneno:s3});
this.collection.add(cont);
cont.save();
}
},
render : function() {
$(this.el).append("<label><b>First Name</b></label><input id= 'fname' type='text' placeholder='Write ur first name'></input>");
$(this.el).append("<br><label><b>Last Name</b></label><input id= 'lname' type='text' placeholder='Write ur last name'></input>");
$(this.el).append("<br><label><b>Phone Number</b></label><input id= 'phoneno' type='text' placeholder='Write ur phone number'></input>");
$(this.el).append("<br><button id='additems'>ADD</button>");
var showdata=localStorage.getItem('ContactList-backbone',this.model);
console.log(showdata,"showdata");
}
return this;
},
});
var contactManager=new ContactView();
});
This is how I used localstorage
function S4() {
return (((1+Math.random())*0x10000)|0).toString(16).substring(1);
};
function guid() {
return (S4());
};
var Store = function(name)
{
this.name = name;
var store = localStorage.getItem(this.name);
this.data = (store && JSON.parse(store)) || {};
};
_.extend(Store.prototype,
{
save: function() {
localStorage.setItem(this.name, JSON.stringify(this.data));
},
create: function(model) {
if (!model.id) model.id = model.attributes.id = guid();
this.data[model.id] = model;
this.save();
return model;
},
Backbone.sync = function(method, model, options) {
var resp;
var store = model.localStorage || model.collection.localStorage;
switch (method) {
case "create": resp = store.create(model); break;
//I am using only create
}
if (resp) {
options.success(resp);
}
else {
options.error("Record not found");
}
};
The data is getting stored in local storage.
But I can't figure out how to show this data in my table when the page is reloded.
For eg: Iwant to show first name,lname and phone no in table ;
I am new to backbone so plz do help me
Basically you will want to bind the add event in your collection which gets will get called for each item that is being added to the collection and then in the function your binding it to add the code to add the rows to your table. Also you will want to remove the code that is in your current add method that adds the row since it will now be generated when the item gets added to your collection.
Using your code as a base something along the lines of
var ContactView=Backbone.View.extend({
el : $('div#contactmanager'),
events: {
'click #additems' : 'add'
},
initialize: function() {
this.render();
this.collection = new ContactList();
this.collection.bind('add', this.addContact, this);
},
addContact: function(contact) {
//this will get called when reading from local storage as well as when you just add a
//model to the collection
$('#table').append($('<tr><td>' + contect.get('name') + </td></tr>'));
}
Another point being that you have already have underscore.js on your page (since its a requirement for backbone.js) you may want to consider moving your code to generate html to a underscore.js template.
http://documentcloud.github.com/underscore/#template
since you're only using create, you're never going to hit read. Replace your switch statement with by adding a read method
switch (method)
{
case "read":
resp = model.id != undefined ? store.find(model) : store.findAll();
break;
case "create":
resp = store.create(model);
break;
}

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