SerializeData in CompositeView - javascript

I need to pass a value to the listView.template in order to be aware the template about the collection.length.
I think one option is to redefine the serializeData method in order to pass a parameter in this way.
var ListView = Marionette.CompositeView.extend({
initialize: function () {
this.collection.on('reset', this.serializeData, this);
this.collection.on('remove', this.serializeData, this);
this.collection.on('add', this.serializeData, this);
},
serializeData: function () {
console.log(this.collection.length);
return {
has_tasks: this.collection.length > 0
};
},
// other codes
});
When I start the app the collection is not yet fetched so:
1.a) the collection.legth = 0
2.b) the template get has_tasks = false as expected.
2.a) after the fetch the collection.length is > 0,
2.b) the serializeData is called and so it puts the has_tasks = true,
2.c) the template seems to be not rendered because it maintains the has_tasks = false
Any idea because 2.c?

Latest Marionette has solved this problem by calling an optional templateHelpers on the view to provide additional context to the view. Also your event binding is not Marionette-friendly as it it will not be auto-unbound correctly when the view is unloaded. So all you need to do in your view is:
var ListView = Marionette.CompositeView.extend({
initialize: function () {
this.bindTo(this.collection, "add", this.render, this);
this.bindTo(this.collection, "remove", this.render, this);
this.bindTo(this.collection, "reset", this.render, this);
},
templateHelpers: function () {
console.log(this.collection.length);
return {
has_tasks: this.collection.length > 0
};
},
// other codes
});
Note, however, that you probably don't want to rerender the entire view and all the sub-elements every time an item is added or removed. A better approach is to only update the count displayed. For instance:
var ListView = Marionette.CompositeView.extend({
initialize: function () {
this.bindTo(this.collection, "add", this.updateCount, this);
this.bindTo(this.collection, "remove", this.updateCount, this);
this.bindTo(this.collection, "reset", this.updateCount, this);
},
updateCount: function() {
this.$('.count_span').html(this.collection.length);
},
// other codes
});

I would simply use something like:
var ListView = Marionette.CompositeView.extend({
initialize: function () {
this.bindTo(this.collection, 'reset', this.render)
},
serializeData: function () {
return { has_tasks: this.collection.length > 0 }
}
});
Calling serializeData again will have no effect on your view. You need to render it again in order to show the new values (because render will get the data by calling serializeData again).
Anyway what is the point of sending hasTask to the template since you can access the collection (and thus its length)?

Related

Collection not firing listen events

In my backbone collection I am working with a collection view at the moment, the view is generated "on the fly".
I am struggling to get the view to update when something is added to the collection, on debugging I have noticed that the collection does not have a _listenid which in my limited knowledge I assume means it cannot listen for the events bound to it?
What would this be happening?
Here is my view,
Pops.Views.ProjectManagers = Backbone.View.extend({
className: 'ui-user-list ui-user-list--single',
template: _.template($("#tpl-project-managers").html()),
events: {
"click .js-add-user": "addUser"
},
initialize: function () {
// this.collection.on('all', function() {
// console.log(arguments);
// });
// this.collection.on('reset', this.render, this);
console.log(this.collection);
this.collection.on('add', this.addOneProjectManager, this);
},
render: function () {
//alert("!!!!!");
this.$el.html(this.template());
this.addAllProjectManagers();
return this;
},
addAllProjectManagers: function () {
this.collection.each(this.addOneProjectManager, this);
},
addOneProjectManager: function (model) {
console.log(model);
if(this.model.get('is_admin') == true) {
model.set('admin', true);
}
var teamMember = new App.Views.SingleTeamMember({
model: model,
project: this.model
});
this.$('.ui-member-list').prepend(teamMember.render().el);
},
});
If I physically refresh the page, the collection then has a _listenid
I initialise this view like this,
var projectManagerList = new Pops.Views.ProjectManagers({
model : this.model,
collection : this.model.get('project_manager')
});
and this is the model I pass through,

Re-render view without models changed backbone

i'm rendering a view from a collection of user.When a specific attribute(Status=online,offline) in a user change the view correctly show on the dom the value of attribute changed. But if i want render the view without the model in which the attribute is changed or viceversa add to view a model in wich attribute is changed?
This is a code that send to view a collection with users status online:
var user_on=Models.utenti.filter(function(model){
return model.get('status') === "on";
});
var users_online = new Usercollection(user_on);
var page=new Homelistuser({model:users_online});
this.changePage(page);
And this is a view:
var Homelistuser = Backbone.View.extend({
tagName: "ul",
id: "list",
template: Handlebars.compile(template),
initialize: function () {
Models=this.model;
this.model.bind("reset", this.render, this);
$(window).on('orientationchange', this.onOrientationChange);
},
render: function (eventName) {
$(this.el).empty();
_.each(this.model.models, function (ad) {
$(this.el).append(new SingleUserView({
model: ad
}).render().el);
}, this);
return this;
},
You could filter online users in the render function of your view, I believe you called the users_online collection as model in it, so:
model.reset(model.filter(function(model){
return model.get('status') === 'on';
}));
or maybe just filter elements out as you append SingleUserViews
_.each(this.model.models, function (ad) {
if (ad.get('status') !== 'on') return;
$(this.el).append(new SingleUserView({
model: ad
}).render().el);
}, this);

Collection add event listener in Backbone

I am trying to update my view whenever I add a new model to my collection. My first question is do I automatically add a model to my collection when I save that model, like:
PostsApp.Views.Form = Backbone.View.extend({
template: _.template($('#form-template').html()),
render: function(){
this.$el.html(this.template(this.model.toJSON()));
},
events:{
'click button' : 'save'
},
save: function(e){
console.log("is this working");
e.preventDefault();
var newname = this.$('input[name=name-input]').val();
var newadress = this.$('input[name=adress-input]').val();
this.model.save({name: newname, adress : newadress});
}
});
or do I still have to do collection.add()
Other than that to see the new model in my view I am trying to add an 'add' event listener like this:
PostsApp.Views.Posts = Backbone.View.extend({
initialize: function(){
this.collection.on('add', this.addOne, this);
},
render: function(){
this.collection.forEach(this.addOne, this);
},
addOne: function(post){
var postView = new PostsApp.Views.Post({model:post});
postView.render();
this.$el.append(postView.el);
}
});
This not only doesnt work, but when I add the initialize method, it just duplicates everything in my model when the page is first loaded.
Nope.. When you do a model.save , it will just create a zombie model ( If it not already a part of the collection .i.e If a New model is saved) which is not a part of any collection.
So your add event will not be triggered for the collection.
If you want the add event to be triggered , Use the create method of collection , which then will know on which collection the new model has to be added..
collection.create({model});
Then it would internally add the model to the collection and fire the add event
Also it is a better idea to use listenTo instead of attaching events using on
this.listenTo(this.collection, 'add', this.addOne);
Code
PostsApp.Views.Form = Backbone.View.extend({
template: _.template($('#form-template').html()),
render: function () {
this.$el.html(this.template(this.model.toJSON()));
},
events: {
'click button': 'save'
},
save: function (e) {
console.log("is this working");
e.preventDefault();
var newname = this.$('input[name=name-input]').val();
var newadress = this.$('input[name=adress-input]').val();
this.collection.create({
name: newname,
adress: newadress
});
}
});
PostsApp.Views.Posts = Backbone.View.extend({
initialize: function () {
this.listenTo(this.collection, 'add', this.addOne);
},
render: function () {
this.collection.forEach(this.addOne, this);
},
addOne: function (post) {
var postView = new PostsApp.Views.Post({
model: post,
collection : this.collection
});
postView.render();
this.$el.append(postView.el);
}
});

Getting the attribute from a View's Model when the view is clicked (backbone.js)

When a user clicks on a div with class .photo_container which is part of the view PhotoListView, there is a function sendSelectedPhotoId that will be triggered. This function has to get the attribute photo_id from the Photo model that belongs to this view whose div .photo_container element has been clicked, and send it to the serverside via fetch().
Problem: So far I managed to get the function sendSelectedPhotoId to be triggered when the div is clicked, but I cant figure out how to get the photo_id attribute of the view's Photo model. How should I achieve this?
On a side note, I'm not sure whether the correct photo_id will be send.
Code
$('#button').click( function() {
// Retrieve photos
this.photoList = new PhotoCollection();
var self = this;
this.photoList.fetch({
success: function() {
self.photoListView = new PhotoListView({ model: self.photoList });
$('#photo_list').html(self.photoListView.render().el);
}
});
});
Model & Collection
// Models
Photo = Backbone.Model.extend({
defaults: {
photo_id: ''
}
});
// Collections
PhotoCollection = Backbone.Collection.extend({
model: Photo,
url: 'splash/process_profiling_img'
});
Views
// Views
PhotoListView = Backbone.View.extend({
tagName: 'div',
events: {
'click .photo_container': 'sendSelectedPhotoId'
},
initialize: function() {
this.model.bind('reset', this.render, this);
this.model.bind('add', function(photo) {
$(this.el).append(new PhotoListItemView({ model: photo }).render().el);
}, this);
},
render: function() {
_.each(this.model.models, function(photo) {
$(this.el).append(new PhotoListItemView({ model: photo }).render().el);
}, this);
return this;
},
sendSelectedPhotoId: function() {
var self = this;
console.log(self.model.get('photo_id'));
self.model.fetch({
data: { chosen_photo: self.model.get('photo_id')},
processData: true,
success: function() {
}});
}
});
PhotoListItemView = Backbone.View.extend({
tagName: 'div',
className: 'photo_box',
template: _.template($('#tpl-PhotoListItemView').html()),
initialize: function() {
this.model.bind('change', this.render, this);
this.model.bind('destroy', this.close, this);
},
render: function() {
$(this.el).html(this.template( this.model.toJSON() ));
return this;
},
close: function() {
$(this.el).unbind();
$(this.el).remove();
}
});
SECOND ATTEMPT
I also tried placing the event handler and sendSelectedPhotoId in the PhotoListItemView where I managed to get the Model's attribute properly, but I can't figure out how to trigger the reset event when the PhotoList collection did a fetch().
View
PhotoListItemView = Backbone.View.extend({
tagName: 'div',
className: 'photo_box',
events: {
'click .photo_container': 'sendSelectedPhotoId'
},
template: _.template($('#tpl-PhotoListItemView').html()),
initialize: function() {
this.model.bind('change', this.render, this);
this.model.bind('destroy', this.close, this);
},
render: function() {
$(this.el).html(this.template( this.model.toJSON() ));
return this;
},
close: function() {
$(this.el).unbind();
$(this.el).remove();
},
sendSelectedPhotoId: function() {
console.log('clicked!');
var self = this;
console.log(self.model.get('photo_id'));
self.model.fetch({
data: { chosen_photo: self.model.get('photo_id')},
processData: true,
success: function() {
$(this.el).html('');
}});
}
});
Problem: With this, I cant seem to fire the reset event of the model after doing the fetch() in function sendSelectedPhotoId, which means I cant get it to re-render using PhotoListView's render().
In the screenshot below from Chrome's javascript console, I printed out the collection after sendSelectedPhotoId did its fetch(), and it seems like the fetched added the new data to the existing model, instead of creating 2 new models and removing all existing model!
You already have child views for each model, so I would put the click event handler in the child view. In the handler in the child, trigger an event passing this.model, and listen for that event in your parent.
Update based on update:
Try changing
this.model.bind('reset', this.render, this); to
this.model.bind('remove', this.render, this); // model is a collection right?
and then remove the model from the collection after the view is clicked. Also, I don't think using Model.fetch is what you really want to do. Maybe a .save or a custom method on the model?
Update based on author's comment showing sample base from blog
I would not follow that blog's advice. If you are using backbone professionally I can't recommend the Thoughtbot ebook enough.
It's $50 for a work in progress, and it's worth every penny
It has a simple sample application that lays out how to organize a backbone app. This is why I bought the book.
It uses Rails in the examples for the backend, but I have used Rails, Node, and C# MVC and all work no problem.

no existant $(this.el) in backbone view while rendering child view

full code here... http://pastebin.com/EEnm8vi3
line 378 is not inserting the sections into the current view. the section model is correctly being passed into the method. everything else works as expected except for the insertion of the child rendered views.
I am wanting to know why $(this.el) is empty and therefore not allowing an append. trying to use a direct selector like $('#sections') also does not work.
relevent code repeated from pastbin link above: (addOne method)
SCC.Views.SectionView = Backbone.View.extend({
tagName: "div",
className: "section",
initialize: function(){
_.bindAll(this, 'render');
this.template = _.template($('#section-tmpl').html());
},
render: function() {
console.log($(this.el));
$(this.el).html(this.template(this.model.toJSON()));
return this;
}
});
SCC.Views.SectionsView = Backbone.View.extend({
tagName: "div",
id: "sections",
className: "sections",
initialize: function(){
_.bindAll(this, 'render');
//SCC.Sections.bind('add', this.addOne, this);
SCC.Sections.bind('reset', this.addAll, this);
SCC.Sections.bind('all', this.render, this);
},
render: function() {
$(this.el).html("<p>rendered</p>");
return this;
},
addOne: function(section) {
var view = new SCC.Views.SectionView({model: section});
$(this.el).append(view.render().el);
},
addAll: function() {
this.collection.each(this.addOne);
}
});
SCC.Sections = new SCC.Collections.Sections();
SCC.SectionsView = new SCC.Views.SectionsView({collection:SCC.Sections});
SCC.Sections.reset(window.SectionData);
$('#main').append(SCC.SectionsView.render().el);
I ran into this problem myself and so I'll leave this answer for anyone else out there:
When you bind this.render to 'all' as #lukemh did:
SCC.Sections.bind('all', this.render, this);
You're effectively saying everytime an event is triggered in the model/collection re-render the view. When you use .html() in that render method you're also going to override any child views that may have been .append()'ed to it throught the addOne function.
If you move the $(this.el).html() call to the initialize view the problem is solved. You can still bind render to 'all' but make sure you're only re-rendering a portion of it or else you'll override the child views again.

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