Backbone.Model `defaults` interfering with `set`? - backbone.js

I notice when I have code like: http://jsfiddle.net/MtULf/1/
window.Todo = Backbone.Model.extend({
defaults: {
"title": ""
},
validate: function() {
if (this.get("title") === "")
return "Title is missing!"
}
});
var todo = new Todo();
console.log("Expects blank: ", todo.get("title"));
todo.set({ title: "A valid title" });
console.log("Expects 'A valid title': ", todo.get("title"));
todo.set("title", "");
console.log("Expects blank: ", todo.get("title"));
All set(...) seems to fail: todo.get("title") always returns empty string
However, if I remove the defaults, I get expected output: http://jsfiddle.net/MtULf/2/
window.Todo = Backbone.Model.extend({
validate: function() {
if (this.get("title") === "")
return "Title is missing!"
}
});

validate isn't getting the model as it's context so you need to work with the function attributes, then it works as intended (except validate prevents the title being set to blank)
http://jsfiddle.net/MtULf/3/
no, that's not true, is it.. validate does get the model as it's context, but validate runs before the values are set in the model so it always fails when the default is set to "" but succeeds without default because undefined ! === "".
ok, I think I got it that time..

Related

Ember array serialization

I'm adding objects to an array property of a model, then saving it. When I look at the outgoing request, the property in question is always an empty array.
My custom serializer (extending Ember.RESTSerializer) has this:
DS.ArrayTransform = DS.Transform.extend(
{
deserialize: function(serialized)
{
return (Ember.typeOf(serialized) == "array") ? serialized : [];
},
serialize: function(deserialized)
{
var type = Ember.typeOf(deserialized);
if (type == 'array')
{
return [{foo:'bar'}];
// return deserialized;
}
else if (type == 'string')
{
return deserialized.split(',').map(function(item)
{
return item.trim();
});
}
else
{
return [];
}
}
});
App.register("transform:array", DS.ArrayTransform);
As you can see I've tried passing back an arbitrary array with an object in it, but even then the array always comes out as empty. In the app I create the record like this:
var post = this.store.createRecord('explorePost', {
title: content.get('title'),
text: content.get('text'),
postDate: content.get('postdate'),
publishDate: content.get('publishDate'),
published: content.get('published'),
postType: content.get('postType'),
link: content.get('link,'),
projectDownloads: [],
// projectDownloads: this.model.get('projectDownloads'),
projectLinks: content.get('projectLinks'),
});
then add the objects like this:
this.model.get('projectDownloads').forEach(function (_download) {
console.log('pushing download', _download);
post.get('projectDownloads').pushObject(_download);
});
I can confirm that at time of saving, the post object has a projectDownloads array with one object in it. No matter what I do I can't seem to get it to spit out the contents when it saves. It's definitely going into the custom serializer, and detects it as an array, but you can see something else seems to be overriding it.
Can anyone tell me what I'm doing wrong? My model setup is below:
App.ExplorePost = DS.Model.extend(
{
title: DS.attr('string'),
text: DS.attr('string'),
link: DS.attr('string'),
postDate: DS.attr('momentdate'),
publishDate: DS.attr('momentdate'),
user: DS.belongsTo('user',{async:true}),
postType: DS.attr('string'),
activity: DS.belongsTo('activity',{ inverse: 'explorePost', async:true}),
comments: DS.hasMany('comment',{ inverse: 'explorePost', async: true }),
// projectDownloads: DS.hasMany('projectDownload',{ inverse: 'explorePost'}),
projectDownloads: DS.attr('array'),
// projectLinks: DS.hasMany('projectLink',{ inverse: 'explorePost'}),
projectLinks: DS.attr('string'),
published: DS.attr('boolean', {defaultValue: true}),
// tags: DS.hasMany('tag')
sortdate: function()
{
var datestr = Ember.isEmpty(this.get('postDate')) ? '' : moment(this.get('postDate')).format('YYYYMMDDHHmm');
var fn = (datestr + '____________').slice(0, 12);
return fn;
}.property('postDate')
});
There's no built in DS.attr('array') and a naive implementation would probably not know how to serialize ember-data objects found inside. Did you intend to leave that in there? If you swap it back to the relationships you've commented out and change projectDownloads to work with the promise:
this.model.get('projectDownloads').then(function(downloads) {
downloads.forEach(function(_download){
post.get('projectDownloads').pushObject(_download);
});
});
This should work jsut fine. I put together something nearly identical the other day. http://emberjs.jsbin.com/zolani/3/edit?html,css,js,output
if you array not contain complex object, like array of string, you can use DS.attr(), it will work.

Routing in Ionic

I have an Ionic app where I am calling $http through a factory:
.factory('Articles', function ($http) {
var articles = [];
return {
all: function () {
return $http.get("http://jsonp.afeld.me/?url=http://examplesite.com/page.html?format=json").then(function (response) {
articles = response.data.items;
console.log(response.data.items);
return articles;
});
},
get: function (articleId) {
for (var i = 0; i < articles.length; i++) {
if (articles[i].id === parseInt(articleId)) {
return articles[i];
}
}
return null;
}
}
});
It is working fine and displays a list of articles but when I want to go into a specific article it just shows a blank page even though the url shows the correct article ID. My controller for a single article looks like this:
.controller('MyCtrl', function ($scope, $stateParams, Articles) {
$scope.article = Articles.get($stateParams.articleId);
})
The returned data looks like this (The ID seems to be coming through as a string but using "parseInt" so really not sure what is going on):
0: Object
alias: "title"
attachments: Array[0]
author: Object
category: Object
catid: "67"
created: "2015-04-11 08:06:07"
created_by_alias: ""
events: Object
extra_fields: null
featured: "0"
fulltext: ""
gallery: null
hits: "80"
id: "171"
image: ""
imageLarge: "/url/69bc9c3e85c501b0a6208cc7a55abbf9_L.jpg"
imageMedium: "/url/69bc9c3e85c501b0a6208cc7a55abbf9_M.jpg"
imageSmall: "/url/69bc9c3e85c501b0a6208cc7a55abbf9_S.jpg"
imageWidth: ""
imageXLarge: "/url/69bc9c3e85c501b0a6208cc7a55abbf9_XL.jpg"
imageXSmall: "/url/69bc9c3e85c501b0a6208cc7a55abbf9_XS.jpg"
image_caption: ""
image_credits: ""
introtext: "<p><strong>Mpho Mathoho</strong>lots of text is here....</p>"
language: "*"
link: "/url/title.html"
modified: "2015-06-02 07:44:30"
numOfComments: "0"
numOfvotes: "(0 votes)"
tags: Array[1]
title: "the title"
video: null
video_caption: ""
video_credits: ""
votingPercentage: 0
__proto__: Object
I guess you need to use parseInt() on both fields, change the line:
if (articles[i].id === parseInt(articleId)) {
To:
if (parseInt(articles[i].id) === parseInt(articleId)) {

Check input value against an array

I am using this plugin for my autocomplete form:
http://www.planbox.com/blog/news/updates/jquery-autocomplete-plugin-for-backbone-js.html
Instead of checking only one item, as in the code below (if (inputVal == 'bakaxel')),
I would like to check the selected value against the entire collection
var collection = new Backbone.Collection([
{id:"AB", name:"Alberta"},
{id:"AD", name:"Album"},
{id:"BA", name:"barn"},
{id:"BC", name:"bak"},
{id:"BD", name:"baby"},
{id:"BE", name:"band"},
{id:"BF", name:"bakaxel"},
{id:"BG", name:"batteri"},
{id:"BH", name:"barbie"},
{id:"MB", name:"Manitoba"},
{id:"AP", name:"Armed Forces Pacific"}
]);
$('input.search').autocomplete({
collection: collection,
attr: 'name',
noCase: true,
ul_class: 'search_options tr_list',
ul_css: {'z-index':1234}
});
$('input.search').each(function(){
$(this).blur(function(){
var inputVal = $('input.search').val();
if (inputVal == 'bakaxel') {
$('#search_result_page').load('searchResult.html');
$('#searchPage').addClass('hidden');
}
});
});
I tried this, but I'd rather not create the ar array again, just use the backbone collection:
$('input.search').each(function(){
$(this).blur(function(){
var inputVal = $('input.search').val();
var ar = ["Alberta", "Album", "barn", "bak", "baby", "band", "bakaxel", "batteri", "barbie", "Manitoba", "Armed Forces Pacific"];
if (jQuery.inArray(inputVal, ar) != -1) {
$('#search_result_page').load('searchResult.html');
$('#searchPage').addClass('hidden');
}
});
});
Backbone proxies Underscore functions and most notably in your case http://underscorejs.org/#where
where _.where(list, properties)
Looks through each value in the list, returning an array of all the values that contain all of the
key-value pairs listed in properties.
Your test could be written as
var matches = collection.where({
name: inputVal
});
if (matches.length>0) {
...
}
Or as #mu suggested in the comments, you could just check the existence of the input with http://underscorejs.org/#find
var found = collection.find(function(model) {
return model.get('name') === inputVal
});
if (found) {
...
}

Store/push to an array in a Backbone Model

I have this model defaults:
test.Models.ItemModel = Backbone.Model.extend({
defaults: {
name: 'an item',
units: []
},
Which I then use the following code to set the Model:
addUnit: function(e){
if(e.keyCode == 13){
this.model.set({ 'units' : this.model.get('units').push($('#addUnit').val()) },
{success: function(){
this.render();
}}
);
}
},
However, it never seems to get added to the Model array, am I doing things right here??
The problem is that you're assuming the the push method is returning the whole array; instead, as stated here, the push method
Returns the new length property of the object upon which the method was called.
So, you need to push the element into the array before you set it to the model :
var _units = this.model.get('units');
_units.push($('#addUnit').val());
this.model.set({ 'units' : _units });
Careful though, this will modify anything else that points to this array, so if you do this, for example:
var myArray = [1,2,3]
this.model.set({units: myArray})
var _units = this.model.get('units')
_units.push(4)
this.model.set({ 'units' : _units })
myArray == this.model.get('units') // holy moly, they're the same :(
If you want to avoid this, or still want to use a single line of code for that, you could use array's concat method:
this.model.set({
'units' : this.model.get('units').concat($('#addUnit').val())
});

How to report invalid form fields using Backbone.js

I'm using Backbone to manage the state of an HTML form. The Model's role is to handle validation. The View's role is to wrap the HTML form and respond to the change or error events emitted by the model.
Backbone seems to only emit change events when the given field is actually valid. This is causing some really unexpected behavior that makes me thing that I'm doing this wrong.
Here is a summary of what I'm doing:
1. Initial load serializes the form and injects it into the model
2. When an error event is emitted, I generate error nodes next to the invalid field.
3. When a change event is emitted, I remove the error notes next to the (now valid) field.
When a page is rendered with an initially valid form, and a user invalidates a field, the message is displayed as expected; however, the model never updates the field internally. Thus when the user corrects the error, a change event is never emitted.
Example: Initially valid
When a page is rendered with an initially invalid form, things appear to be working fine... but this is only because the model's initial attributes are empty. Correcting the field makes the messages disappear, but if you change it again to an invalid state, the message never disappears.
Example: Initially invalid
What am I doing wrong? Perhaps there's another approach I should be using instead?
My Model
var Foo = Backbone.Model.extend({
validate: function(attr) {
var errors = {};
if (_.isEmpty(attr)) return;
if (attr.foo && attr.foo != 123) {
errors.foo = ['foo is not equal to 123'];
}
if (attr.bar && attr.bar != 456) {
errors.bar = ['bar is not equal to 456'];
}
return _.isEmpty(errors) ? undefined : errors;
}
});
My View
FooForm = Backbone.View.extend({
events: {
'change :input': 'onFieldChange'
},
initialize: function(options) {
this.model.on('error', this.renderErrors, this);
this.model.on('change', this.updateFields, this);
// Debugging only
this.model.on('all', function() {
console.info('[Foo all]', arguments, this.toJSON())
});
this.model.set(this.serialize());
},
onFieldChange: function(event) {
var field = event.target,
name = field.name,
value = field.value;
this.model.set(name, value);
},
renderErrors: function(model, errors) {
_.each(errors, function(messages, fieldName) {
var el = $('#' + fieldName),
alert = $('<div/>').addClass('error');
el.parent().find('.error').remove();
_.each(messages, function(message) {
alert.clone().text(message).insertAfter(el);
});
});
},
updateFields: function(model, options) {
if (!options || !options.changes) return;
_.each(_.keys(options.changes), function(fieldName) {
var el = $('#' + fieldName);
el.parent().find('.error').remove();
});
},
serialize: function() {
var raw = this.$el.find(':input').serializeArray(),
data = {},
view = this;
$.each(raw, function() {
// Get the model's field name from the form field's name
var name = this.name;
if (data[name] !== undefined) {
if (!data[name].push) {
data[name] = [data[name]];
}
data[name].push(this.value || '');
}
else {
data[name] = this.value || '';
}
});
return data;
}
});
You can't validate individual field using native Backbone validation.
In my app I use this validation plugin: https://github.com/thedersen/backbone.validation
Then in your model you add validation rules per each field (it's optional, so you don't need to add this to all models):
var NewReview = Backbone.Model.extend({
initialize: function() {
/* ... */
},
validation: {
summary: {
required: true,
minLength: 10
},
pros: {
required: true,
minLength: 10
},
cons: {
required: true,
minLength: 10
},
overall: function(value) {
var text = $(value).text().replace(/\s{2,}/g, ' ');
if (text.length == 0) text = value;
if (text.length < 20) return "Overall review is too short";
},
rating: {
range: [0.5, 5]
},
product_id: {
required: true
}
}
});
Than in views or elsewhere you can validate either entire model or individual fields:
if (this.model.validate()) { ... }
or
if (this.model.isValid("summary")) { ... }

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