Multiple Views and Sub Views with 1 collection in Backbone - backbone.js

I have issue in rendering Shopping Bag Views using Backbone for my website.
I am using 1 collection for all Bag Views (“Quick_View” of items list & “Normal_View” of Items list). Also I created “Item_View”, which is being used to render each item in both the Views.
It is a SPA (Single Page Application) and “Quick_View” is initiated and rendered for all Backbone routes and hidden by default. Whenever user clicks on “Quick_View” link from any page it is showing. There is no route defined for it.
The “Normal_View”, can be accessed using Checkout button given in “Quick_View”. It is bind with “domain/checkout” route.
When I access “Normal_View” from “Quick_View” check button; it works fine and both (Quick and Normal) views are in Sync. Means, when we add, delete, update any item in any of the View, both Views are getting updated accordingly.
But when I access “domain/checkout” route directly in a new browser, both views are getting rendered fine, but they are not in sync. Means, change in 1 view does not update another view.
The reason, I tracked is, when I access “Normal_View” through “Quick_View”, model for each item in both the Views having same CID, so the both Views are in sync, if there is any change in a model from any of the View.
And, when I access “Normal_View” directly, model for each item in both the views are not having same CID, so they do not work as expected.
There are few more points to consider:
Collection is firing reset event twice for “Quick_View” and each item
in “Quick_View” is rendering twice.
When, I access “Normal_View” (in either way), “Quick_View” is again getting rendered but once “Normal_View” rendering is over.
// Main View
var mainView = Backbone.View.extend({
el: 'body',
template: {
header: Handlebars.compile(headerTemplate),
mainNav: Handlebars.compile(mainNavtemplate),
footer: Handlebars.compile(footerTemplate)
},
initialize: function() {
_.bindAll();
AW.collection.bag = new bagCollection();
//AW.collection.bag.fetch({reset:true});
},
render: function() {
this.$el.html(this.template());
this.loadSubView('bagQV');
},
loadSubView: function(subView) {
switch(subView) {
case 'home' :
if(!AW.view.home) AW.view.home = new homepageView();
AW.view.home.render();
break;
case 'bagQV' :
if(!AW.view.bagQV) AW.view.bagQV = new bagQuickView({collection: AW.collection.bag});
//AW.view.bagQV.render();
break;
case 'checkout' :
if(!AW.view.checkout) AW.view.checkout = new checkoutView({collection: AW.collection.bag});
AW.view.checkout.render();
break;
}
}
});
// Single Item View
var bagItemView = Backbone.View.extend({
tagName: 'tr',
template: Handlebars.compile(bagItemTemplate),
initialize: function() {
_.bindAll(this);
this.listenTo(this.model, 'change', this.render);
this.listenTo(this.model, 'remove', this.removeItem);
$(document).on('keyup', this.listenKeyboard);
},
events: {
'click .qtyInput .button' : 'updateItem',
'click .controls a.remove' : 'removeModel'
},
render: function() {
this.$el.html(this.template(this.model.toJSON()));
this.$el.attr('data-id',this.model.cid);
return this;
},
updateItem: function(e) {
e.preventDefault();
e.stopPropagation();
var newQty = this.$el.find('.qtyInput input').val();
var newAmt = newQty * parseFloat(this.model.get('prodRate').replace('$',''));
this.model.set({prodQty: newQty, amount: '$' + newAmt});
this.cancelEdit(e);
},
removeModel: function(e) {
e.preventDefault();
e.stopPropagation();
if(AW.collection.bag) AW.collection.bag.remove(this.model);
},
removeItem: function() {
this.$el.remove();
}
});
// Bag Quick View
var bagQuickView = Backbone.View.extend({
tagName: 'div',
id: 'myBagQV',
template: Handlebars.compile(bagQuickViewTemplate),
initialize: function() {
_.bindAll(this);
this.collection.fetch({reset:true});
//this.collection.bind("reset", _.bind(this.render, this));
this.listenTo(this.collection, 'add', this.addItem);
this.listenTo(this.collection, 'reset', this.render);
},
render: function() {
if($('#myBagQV').length == 0) {
this.$el.html(this.template());
$('body').append(this.el);
}
this.addAllItems();
return this;
},
addItem: function(item) {
var parent = this;
var itemView = new bagItemView({model: item});
$('#itemsInBag table tbody').append(itemView.render().el);
},
addAllItems: function() {
if(this.collection.length > 0) {
$('#itemsInBag table tbody').html('');
this.collection.each(this.addItem, this);
}
},
});
// Normal Bag View
var bagView = Backbone.View.extend({
tagName: 'div',
id: 'myBag',
template: Handlebars.compile(checkoutBagTemplate),
initialize: function() {
_.bindAll(this);
this.collection.fetch({reset:true});
//this.collection.bind("reset", _.bind(this.render, this));
this.listenTo(this.collection, 'add', this.addItem);
this.listenTo(this.collection, 'reset', this.render);
},
render: function() {
this.$el.html(this.template());
$('#checkoutContainer #details').append(this.el);
this.addAllItems();
return this;
},
addItem: function(item) {
var parent = this;
var itemView = new bagItemView({model: item});
this.$el.find('table tbody').append(itemView.render().el);
},
addAllItems: function() {
if(this.collection.length > 0) {
this.$el.find('table tbody').html('');
this.collection.each(this.addItem, this);
}
}
});
Looking for you help.
Thank you in advance
Cheers,
Vikram

Related

Render Collection model in backbone

Generally when design view for Collection(s), I would bind the collection to the view, and register related events to the collection like this:
var Book = Backbone.Model.extend({});
var BookList = Backbone.Collection.extend({
model: Book,
url: "/books"
});
var BookListItemView = Backbone.View.extend({
mtemplate: _.template($('#tpl_book_item').html()),
render: function () {
this.$el = $(this.mtemplate(this.model.toJSON()));
return this;
}
});
var BookListView = Backbone.View.extend({
el: '#content',
initialize: function () {
this.listenTo(this.collection, 'add', this.render);
this.listenTo(this.collection, 'remove', this.render);
},
render: function () {
this.$el.empty();
this.collection.each(function (item) {
this.$el.append(new BookListItemView({model: item}).render().$el);
}, this);
return this;
}
});
Use:
var books = new BookList();
var bookListView = new BookListView({
collection: books
});
books.fetch();
It worked as expected: render every book as defined in the template. However I found that there is a slight stuck in the page.
I am not sure if this is caused by the re-rendering the view? As shown, when the books.fetch complete, it will add books to the collection of books, for each book item, an add event will be triggered, then I will re-render the page by removing the exist item and iterate the collection.
Which means once there are 10 books, there will be 1+2+3+4...+10 loops for the BookListView.
I my opinion, once the add event triggered, I should not refresh the whole list but just add a new view to the BookListView, but how about the remove event, it seems that Backbone does not provide any internal method to get the view from the model, so once a model to be removed, I can not get the related view.
How do you handle this kind of suitation?
Do not bind your add to the render function. Instead create a dedicated add method for that.
var Book, BookList, BookListItemView, BookListView;
Book = Backbone.Model.extend({});
BookList = Backbone.Collection.extend({
model: Book,
url: "/books"
});
BookListItemView = Backbone.View.extend({
mtemplate: _.template($("#tpl_book_item").html()),
initialize: function() {
this.model.on("remove", this.remove);
},
render: function() {
this.$el = $(this.mtemplate(this.model.toJSON()));
return this;
}
});
BookListView = Backbone.View.extend({
el: "#content",
initialize: function() {
this.listenTo(this.collection, "add", this.addItem);
},
render: function() {
this.$el.empty();
this.collection.each((function(item) {
this.addItem(item);
}), this);
return this;
},
addItem: function(item) {
this.$el.append(new BookListItemView({
model: item
}).render().$el);
}
});
Let the models own View handle its own remove event.

Backbone Client Side Collection Filtering

Consider a backbone app that has a select list of categories, and a table of files underneath it. All files, regardless of the category they belong to are in the App.collection.files collection. When a user selects a new category, I'd like to filter the table to only show those matching files.
I'd like to do this completely on the client side. I do NOT want to fetch a new list of files from the server each time a new category is picked.
I plan to to a App.collection.files.where({category_id: xx}) within App.View.Files.render() to accomplish the filtering itself.
What is the best Backbone-y way to trigger/respond to an event to get this working?
One idea I am playing with is another collection, that contains the filtered files, but not sure if this is the best approach.
App.View.FilesPage = Backbone.View.extend({
template: App.utils.template('files-page'),
className: 'container-fluid',
initialize: function(){
this.render();
},
render: function(){
this.$el.html(this.template());
this.$el.find('.categories').append(
new App.View.Categories({collection:App.collection.categories}).el
);
this.$el.find('.files table').append(
new App.View.Files({collection:App.collection.files}).el
);
return this;
}
});
App.View.Categories = Backbone.View.extend({
tagName: 'select',
events: {
'change': 'onChange'
},
initialize: function(){
this.$el.attr('size', this.collection.length + 1);
this.render();
},
render: function(){
var option = function(value, text, isSelected){
return $('<option></option>', {'value':value, 'text':text});
};
this.$el.html(option(0, 'All Documents'));
this.$el.append(
this.collection.invoke(function(){
return option(this.get('category_id'), this.get('title'));
})
).val(0);
return this;
},
onChange: function(event){
}
});
App.View.Files = Backbone.View.extend({
tagName: 'tbody',
initialize: function(){
this.render();
},
render: function(){
this.$el.html(
this.collection.invoke(function(){
return new App.View.File({model:this}).el;
})
);
return this;
}
});
Here is one solution I came up with, that seems fine and dandy on the surface.
Code changes are called out within comments.
Thoughts on this solution, and completely different solutions are welcome.
App.View.FilesPage = Backbone.View.extend({
template: App.utils.template('files-page'),
className: 'container-fluid',
initialize: function(){
// CHANGE: Store application wide reference to 'Categories' model
App.model.categories = new App.Model.Categories();
this.render();
},
render: function(){
this.$el.html(this.template());
this.$el.find('.categories').append(
new App.View.Categories({
// CHANGE: Pass model into 'Categories' view
model: App.model.categories,
collection: App.collection.categories
}).el
);
this.$el.find('.files table').append(
new App.View.Files({collection:App.collection.files}).el
);
return this;
}
});
App.View.Categories = Backbone.View.extend({
tagName: 'select',
events: {
'change': 'onChange'
},
initialize: function(){
this.$el.attr('size', this.collection.length + 1);
this.render();
},
render: function(){
var option = function(value, text, isSelected){
return $('<option></option>', {'value':value, 'text':text});
};
this.$el.html(option(0, 'All Documents'));
this.$el.append(
this.collection.invoke(function(){
return option(this.get('category_id'), this.get('title'));
})
).val(0);
return this;
},
onChange: function(){
// CHANGE: Update attribute within 'Categories' model
this.model.set('category_id', this.$el.val());
}
});
App.View.Files = Backbone.View.extend({
tagName: 'tbody',
initialize: function(){
this.collection.on('reset', this.render, this);
// CHANGE: Listen for change on 'Categories' model, and re-render this view
App.model.categories.on('change:category_id', this.render, this);
this.render();
},
render: function(){
this.$el.html(
_.invoke(this.getFilteredFiles(), function(){
return new App.View.File({model:this}).el;
})
);
return this;
},
// CHANGE: Return a filtered set of models from collection, based on 'Categories' model attributes
getFilteredFiles: function(){
var categoryId = App.model.categories.get('category_id');
if (categoryId!=0){
return this.collection.where({'category_id': categoryId});
}
else{
return this.collection.models;
}
}
});

detect select status of options in a multiselect with backbone.picky

I have a multiselect dropdown that I'm rendering with Backbone. As user selects or deselects options, I'd like those (de)selections to be saved asynchronously via Backbone.
I found Backbone.Picky, and thought it might be helpful in my endeavor, but I can't seem to get it to detect selects.
In my FieldView's clicked function below, console.log(this.model.selected); always writes undefined to the log. Why?
var Field = Backbone.Model.extend({
initialize: function(){
var selectable = new Backbone.Picky.Selectable(this);
_.extend(this, selectable);
}
});
var FieldView = Backbone.View.extend({
tagName: "option",
initialize: function(){
_.bindAll(this, 'render');
},
events: {
"click":"clicked"
},
clicked: function(e) {
var data_type = this.model.get("DATA_TYPE");
console.log(this.model.selected); // why is this undefined?
console.log("it's a " + data_type);
},
render: function(){
this.$el.attr('value', this.model.get('COLUMN_NAME')).html(this.model.get('display_name'));
return this;
}
});
Here's a jsfiddle http://jsfiddle.net/EAZCt/2/ for more context.
Using Backbone, how can I asynchronously save the select-status of options in a multiselect list?
Your model object doesn't ever have "selected" property because you never select the model. I have never used Backbone.Picky but it seems that you could try:
var FieldView = Backbone.View.extend({
tagName: "option",
initialize: function(){
this.model.on('selected', this.selected, this);
},
events: {
"click":"clicked"
},
clicked: function() {
this.model.select();
},
selected: function() {
var data_type = this.model.get("DATA_TYPE");
console.log(this.model.selected);
console.log("it's a " + data_type);
},
render: function(){
this.$el.attr('value', this.model.get('COLUMN_NAME')).html(this.model.get('display_name'));
return this;
}
});
http://jsfiddle.net/hGEYL/

Backbone.js: how to perform garbage collection on parent views as well as child views

I have implemented a simple close() method for all the Backbone views which disposes of a view when its not needed/needs to be reset.
Backbone.View.prototype.close = function() {
if (this.onClose) {
this.onClose();
}
this.remove();
this.unbind();
};
NewView = Backbone.View.extend({
el: '#List ul',
initialize: function() {},
render: function() {
_(this.collection.models).each(function(item) {
this.renderChildren(item);
}, this);
},
renderChildren: function(item) {
var itemView = new NewChildView({ model: item });
$(this.el).prepend(itemView.render());
},
onClose: function() {
this.collection.reset();
// I want to remove the child views as well
}
});
NewChildView = Backbone.View.extend({
tagName: 'li',
render: function() {
}
});
Now, when I remove the parent view, I also want to remove all the child views here. Any ideas how can I can do this without looping through the models like this....
_(this.collection.models).each(function(item) {
item.close();
}, this);
I think in most of the cases you should keep the view removal in the view layer, without affecting your models.
For example, if you remove a view with comments, maybe another view in your app shows a selection of comments, or some statistics, and resetting the collection would affect those views too.
So I think you should keep it all in the view (only relevant methods included):
NewView = Backbone.View.extend({
initialize: function() {
this.childViews = [];
},
renderChildren: function(item) {
var itemView = new NewChildView({ model: item });
$(this.el).prepend(itemView.render());
this.childViews.push(itemView);
},
onClose: function() {
_(this.childViews).each(function(view) {
view.close();
});
}
});

Backbone.js - Correct way of filtering and displaying collection data in a view

I have got a huge list of tasks loaded on the start.
I want to show them depending on selected list / inbox, so that there won't be additional loadings for each list.
window.Task = Backbone.Model.extend({});
window.TasksCollection = Backbone.Collection.extend({
model: Task,
url: '/api/tasks',
inbox: function() {
return this.filter(function(task) {
return task.get('list') == null;
});
},
list: function(id) {
return this.filter(function(task) {
return task.get('list') == id;
});
}
});
window.tasks = new TasksCollection;
window.TaskView = Backbone.View.extend({
tagName: 'li',
template: _.template($('#item-template').html()),
initialize: function() {
_.bindAll(this, 'render', 'close');
this.model.bind('change', this.render);
this.model.view = this;
},
render: function() {
$(this.el).html(this.template(this.model.toJSON()));
this.setContent();
return this;
},
});
window.TasksView = Backbone.View.extend({
el: '#todo-list',
collection: tasks,
initialize: function() {
_.bindAll(this, 'render');
this.collection.bind('reset', this.render);
this.collection.fetch();
},
render: function() {
var t = this;
$(t.el).html('');
this.collection.each(function(task) {
var view = new TaskView({ model:task });
$(t.el).append( view.render().el );
});
return this;
},
});
window.Nicetask = Backbone.Router.extend({
routes: {
'': 'inbox',
'/inbox': 'inbox',
'/list/:id': 'list',
},
initialize: function() {
_.bindAll(this, 'inbox', 'list');
window.tasksView = new TasksView;
},
inbox: function() {
tasks.reset( tasks.inbox() );
},
list: function(id) {
tasks.reset( tasks.list(id) );
}
});
This code works, but the reset() function removes other tasks in actual list from tasks collection. And on another route, tasks collection is empty.
Is there any reasonable way to achieve this? thanks for any idea.
ps: backbone novice
UPDATE
Thx to #sled and #ibjhb for comments, here is snippet of working solution.
window.TasksView = Backbone.View.extend({
el: '#todo-list',
collection: Backbone.Collection.extend(),
initialize: function() {
_.bindAll(this, 'render', 'addOne', 'addAll');
this.collection.bind('add', this.addOne);
this.collection.bind('reset', this.render);
},
render: function(data) {
$(this.el).html('');
_.each(data, function(task) {
this.addOne(task);
}, this);
return this;
},
addOne: function(task) {
var view = new TaskView({ model:task });
$(this.el).append( view.render().el );
},
});
window.Nicetask = Backbone.Router.extend({
routes: {
'': 'inbox',
'/inbox': 'inbox',
'/today': 'today',
'/list/:id': 'list',
},
initialize: function() {
_.bindAll(this, 'inbox', 'today');
window.tasksView = new TasksView;
window.menuView = new MenuListView;
tasks.fetch();
},
inbox: function() {
tasksView.render( tasks.inbox() );
},
today: function() {
tasksView.render( tasks.today() );
},
list: function(id) {
tasksView.render( tasks.list(id) );
}
});
I think you need to use another collection. For example, in your inbox, do this:
inbox: function(){
currentCollection = new TasksCollection(tasks.inbox());
}
I haven't tested this but when you do a .reset(); you are removing all your models and loading the ones passed in.
#sled there's typos in the code you posted, see comments inline. Did you post this as a project somewhere?
// add models
add: function(models, options) {
// TYPO: next line was missing, so single models not handled.
models = _.isArray(models) ? models.slice() : [models];
var self = this;
models = _.filter(models, this.filter);
// return if no models exist
// TYPO: returned undefined, so was not chainable
if(models.length == 0) { return this; }
// actually add the models to the superset
this.superset.add(models, options);
return this;
},
// remove models
remove: function(models, options) {
// TYPO: next line was missing, so single models not handled.
models = _.isArray(models) ? models.slice() : [models];
// remove model from superset
this.superset.remove(_.filter(_.filter(models, function(cm) {
// TYPO: not 'm != null', causes error to be thrown
return cm != null;
}), this.filter), options);
// TYPO: missing return so not chainable
return this;
},
one quick amendment to you solution, you are using
$(this.el).html('');
My understanding is your the views and related event bindings will still exist in the browser memory, so you ideally need to use view.remove() on the TaskView to correctly clear the event bindings as well as the html.
This is a slightly different take on the answer as I have been looking for a solution to a similar problem, hope this may be of help to others.
My problem: - to filter a complete collection by attributes of the model. eg. a user clicks the models view, gets a list of (some of) the attributes, selecting an attribute filters the collection to only show ones with the same value.
The route I am taking is by calling a method on the collection from the view, in my case the view is specific to a model so:
this.model.collection.myFilter(attr,val);
where attr is an attribute of the model associated with the collection, then in the filter something like
myFilter: function(attr, val){
var groupByAttr = this.groupBy(function(article){
var res = (val === undefined)? true : (article.get(attr) == val);
article.set({selected:res});
return res;
});
return groupByAttr;
}
I have used ._groupBy as this returns 2 arrays (positive / negative) that may be of use. By setting the mode attribute "selected", and binding to this in the model view I can easily toggle a class which shows or hides the view.
if(val === undefined) is added as a simple way of clearing a filter by calling the same method without a value.

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