BackboneJS - How to add a Progressbar while fetching collection - backbone.js

I have an Backbone App where I fetch different collections by clicking a Letter from a list. So, I want to add a Progressbar or some kind of rotating image but I dont know how to do this.
My View looks like this
function (App, Backbone) {
var Artists = App.module();
var ArtistView = Backbone.View.extend({
tagName : 'li',
template: 'artistItem',
serialize: function() {
var data = this.model.toJSON();
data.letter = this.model.collection.letter;
return data;
},
});
Artists.View = Backbone.View.extend({
tagName : 'ul',
className : 'artistList',
initialize: function() {
this.listenTo(this.collection, 'all', this.render);
this.listenTo(App, 'navigateLetter', this.updateState);
},
beforeRender: function() {
var self = this;
this.collection.each(function(item) {
self.insertView(new ArtistView({model: item}))
})
},
updateState: function(letter) {
this.collection.letter = letter;
this.stopListening(this.collection);
this.collection.fetch();
this.listenTo(this.collection, 'all', this.render);
}
});
Artists.ArtistsCollection = Backbone.Collection.extend({
url: function() {
return '/projects/mdk/index.php/api/artists/' + this.letter;
}
});
return Artists;
});
So does anyone have an idea how to do this? I could imagine I should do something in initialize or beforeRender?
Thanks in advance

You can use a spinner for the loading effect. For that you need
spin.js
Add entry of that spin.js into main file.
To use that spinner.
var yourSpinner = new Spinner();
var target = document.getElementById('spinHere');
yourSpinner.spin(target);
e.g in your case take updateState:function(){} :
updateState: function(letter) {
this.collection.letter = letter;
this.stopListening(this.collection);
var yourSpinner = new Spinner();
var target = document.getElementById('spinHere');
yourSpinner.spin(target);
this.collection.fetch();
yourSpinner.stop();
this.listenTo(this.collection, 'all', this.render);
}

Take a look at this: https://github.com/davidsulc/marionette-gentle-introduction/blob/master/assets/js/apps/contacts/list/list_controller.js#L4
It's from my Marionette book app, where the idea is to immediately display a loading view, and when the collection is fetched, render the actual view (and closing the loading view, which is Handled by Marionette). It would give something like (pseudocode):
var loadingView = new ContactManager.Common.Views.Loading();
ContactManager.mainRegion.show(loadingView);
var fetchingContacts = myCollection.fetch();
$.when(fetchingContacts).done(function(contacts){
ContactManager.mainRegion.show(new MyCollView({ collection: contacts }));
});
The code uses a deferred to determine when the collection has been fetched (and therefore the new view should be displayed). You can learn more about using deferreds here:
http://davidsulc.com/blog/2013/04/01/using-jquery-promises-to-render-backbone-views-after-fetching-data/
http://davidsulc.com/blog/2013/04/02/rendering-a-view-after-multiple-async-functions-return-using-promises/

Related

backbone + requirejs: scope issue

I have 2 views, one is a list of "timetracks" and the other is a form to create a timetrack/s
The first one has a collection attached.
The second one, the timetraks form, it defines a "create" function that makes reference to the first one to rerender timetraks view once a new timetrack is created.
timetracks code:
define(['backbone','collections/timetracks', 'views/timetracks/item'], function(Backbone, instanceTimeTracksCollection, TimeTrackView){
var TimeTrackGrid = Backbone.View.extend({
//......
});
return TimeTrackGrid;
});
The form code:
define(['backbone', 'collections/timetracks'], function(Backbone, instanceTimeTracksCollection){
//...............
//next comes my issue:
create: function(){
instanceTimeTracksCollection.create(indexed_array,{
success: function(model, response) {
console.info('model created, response = ',response);
// timeTracksGrid is out of scope, timeTracksGrid would be an instance of timetracks.
timeTracksGrid.render();
},
error: function(error){
console.info('error=',error);
},
wait:true
});
}
});
... and finally I have app.js where the instances of both views are defined:
requirejs(['backbone','views/timetracks/new','views/timetracks/list'],
function(Backbone, newTimeTrackForm, timeTracksGrid) {
var grid = new timeTracksGrid();
var formView = new newTimeTrackForm();
});
How could I render the timetracks view once a new timetrack is created?
**************************** UPDATE *************************************
This is my new version of the code. The issue now is that "this.listenTo(this.collection, "add", this.render);" is overlapping with "this.collection.fetch". As a result the timetracks records are rendered multiple times.
// timetracks view
define(['backbone','collections/timetracks', 'views/timetracks/item'], function(Backbone, timeTracksCollection, TimeTrackView){
var TimeTrackGrid = Backbone.View.extend({
//....
initialize: function(){
_.bindAll(this, 'render', 'generateTimeTracks', 'appendTimeTrack');
this.listenTo(this.collection, "add", this.render);
this.render();
}
render: function(){
$(this.el).html("<table border='1'></table>");
this.collection.fetch({
success: this.generateTimeTracks
});
},
generateTimeTracks : function(){
var self = this;
_(this.collection.models).each(function(item){
self.appendTimeTrack(item);
}, this);
},
appendTimeTrack: function(item){
var timeTrackView = new TimeTrackView({
model: item
});
$('table', this.el).append(timeTrackView.render().el);
}
}
Some other changes:
on app.js instead doing {model:myCollection} as you suggested I'm doing {collection: myCollection}
my form code creates a new model by calling this.collection.create
Thanks again !
A different solution would be to create the views and your collection seperately.
Then in your app.js you could pass the collection to both views. In the initialize function of the TimeTrackGrid you should listen to the "add" event of models on the collections. When such an event is fired you should render the view.
In the create method of your form view you could add the data to your collection. This way your views don't have to know anything about each other which better conforms the Model and View separation.
Thus:
//the grid view
define(['backbone', 'collections/timetracks', 'views/timetracks/item'], function (Backbone, instanceTimeTracksCollection, TimeTrackView) {
var TimeTrackGrid = Backbone.View.extend({
initialize: function () {
//start listening to models being added
this.listenTo(instanceTimeTracksCollection, "add", this.render)
},
render: function () {
//render your view
return this;
}
});
return TimeTrackGrid;
});
//and the form view
define(['backbone', 'collections/timetracks'], function (Backbone, instanceTimeTracksCollection) {
//...............
//next comes my issue:
create: function () {
var data = //get the data from the form
instanceTimeTracksCollection.add(data) //if you have defined a model on your collection, backbone will automatically instantiate the model
}
});
//and you app -> notice the reference to the collection definition
requirejs(['backbone','views/timetracks/new','views/timetracks/list', 'collections/timetrackcollection'],
function(Backbone, newTimeTrackForm, timeTracksGrid) {
var instanceTimeTracksCollection = new TimeTracksCollection();
var grid = new timeTracksGrid({model : instanceTimeTracksCollection});
var formView = new newTimeTrackForm(model : instanceTimeTracksCollection);
});
EDIT=========================================================
fetch the config here
requirejs(['backbone','views/timetracks/new','views/timetracks/list'],
function(Backbone, newTimeTrackForm, timeTracksGrid) {
var grid = new timeTracksGrid();
var formView = new newTimeTrackForm();
var collection = new Collection();
collection.fetch()
});
change your view to:
define(['backbone','collections/timetracks', 'views/timetracks/item'], function(Backbone, timeTracksCollection, TimeTrackView){
var TimeTrackGrid = Backbone.View.extend({
//....
initialize: function(){
_.bindAll(this, 'render', 'generateTimeTracks', 'appendTimeTrack');
// maybe backbone does not fire the add event after fetch
// I believe it does, but I might be mistaken. You will have to look that up
this.listenTo(this.collection, "add", this.render);
this.render();
}
//model is passed to the render method by backbone
render: function(model){
$(this.el).html("<table border='1'></table>");
$('table', this.el).append(new TimeTrackView({model : model}).render().el);
},
//unused now
generateTimeTracks : function(){
var self = this;
// backbone has underscore build in
// so use this instead
this.collection.each(function(item){
//do something with item
}
_(this.collection.models).each(function(item){
self.appendTimeTrack(item);
}, this);
},
//unused now
appendTimeTrack: function(item){
var timeTrackView = new TimeTrackView({
model: item
});
$('table', this.el).append(timeTrackView.render().el);
}
}

Backbone.js reinstantiating collection does not update corresponding view

Here is my Model View and Collection :
window.Report = Backbone.Model.extend({});
window.ReportCollection = Backbone.Collection.extend({
model: Report,
initialize: function(properties){
this.url = properties.url;
}
});
window.ReportCollectionView = Backbone.View.extend({
initialize: function(){
this.collection.reset();
this.render();
},
render: function(){
var self = this;
this.collection.fetch({
success: function(){
self.collection.each(function(model){
//pass model to subview
});
}
}
});
}
});
in the other part of the code I use the instantiate the above objects
var reportCollection = new ReportCollection({url:someURL});
var reportCollectionView = new ReportCollectionView({collection:reportCollection});
'someURL' is a REST based URL that returns JSON list of Objects
So far everything looks good. What I am trying to achieve is:
I must be able to refresh the 'reportCollection' by changing the url and this should trigger an updated 'reportCollectionView'. Thanks for any pointers
I suppose you could add a method to your collection which changes url and forces a fetch:
window.ReportCollection = Backbone.Collection.extend({
//...
changeUrl: function(url) {
this.url = url;
this.fetch();
}
});
and then bind to the "reset" event in your view:
window.ReportCollectionView = Backbone.View.extend({
initialize: function() {
_.bindAll(this, 'render');
this.collection.on('reset', this.render);
this.collection.reset();
},
//...
});
Then if you do this:
c = new ReportCollection(...);
v = new ReportCollectionView({ collection: c, ... });
You'll get your rendered view and then later you can:
c.changeUrl(...);
to set the new URL and that will trigger a render call on v.

Backbone Collection Add Event Firing Once

I have a Backbone collection and when I add a new model to it the "add" event doesn't seem to work as I'd expect. I've bound 2 views to listen for add events on the collection, but only one seems to get notified of the event, and when this happens, no PUT request is sent to my server. When I remove the second bind, the other one works and the PUT request is sent. Here's the code snippets:
var FlagList = Backbone.Collection.extend({
model: Flag // model not shown here... let me know if it would help to see
});
var FlagCollectionView = Backbone.View.extend({
el: $('ul.#flags'),
initialize: function() {
flags.bind('add', this.addFlag, this); // this one doesn't fire!!
},
addFlag: function(flag) {
alert("got it 1"); // I never see this popup
}
});
var AddFlagView = Backbone.View.extend({
el: $("#addFlagPopup"),
events: {
"click #addFlag": "addFlag"
},
initialize: function() {
flags.bind('add', this.closePopup, this); // this one fires!!
}
addFlag: function() {
flags.create(new Flag);
},
closePopup: function() {
alert("got it 2"); // I see this popup
}
});
var flags = new FlagList;
var addFlagView = new AddFlagView;
var flagCollectionView = new FlagCollectionView;
A few suggestions:
ID's vs Classes
you've over qualified your selector by combining a class and an id. jQuery allows this, but the ID selector should be unique on the page anyway so change el: $('ul.#flags') to el: $('ul#flags').
Leveraging Backbone
I like to explicitly pass my collections and/or models to my views and use the magic collection and model attributes on views.
var flags = new FlagList;
var addFlagView = new AddFlagView({collection: flags});
var flagCollectionView = new FlagCollectionView({collection: flags});
which now means that in your view, you will automagically have access to this.collection
unbinding events to avoid ghost views
var FlagCollectionView = Backbone.View.extend(
{
initialize: function (options)
{
this.collection.bind('add', this.addFlag, this);
},
addFlag: function (flag)
{
alert("got it 1");
},
destroyMethod: function()
{
// you need some logic to call this function, this is not a default Backbone implementation
this.collection.unbind('add', this.addFlag);
}
});
var AddFlagView = Backbone.View.extend(
{
initialize: function ()
{
this.collection.bind('add', this.closePopup, this);
},
closePopup: function ()
{
alert("got it 2");
},
destroyMethod: function()
{
// you need some logic to call this function, this is not a default Backbone implementation
this.collection.unbind('add', this.closePopup);
}
});
It looks like I have to agree with #fguillen, that your problem must be somewhere in how you initialize the view, as in my comment I mention that it's most likely related to timing, ie: binding your event to the collection after the 'add' event has already fired.
This code works for me:
var FlagList = Backbone.Collection.extend({});
var FlagCollectionView = Backbone.View.extend({
initialize: function() {
flags.bind('add', this.addFlag, this);
},
addFlag: function(flag) {
alert("got it 1");
}
});
var AddFlagView = Backbone.View.extend({
initialize: function() {
flags.bind('add', this.closePopup, this);
},
closePopup: function() {
alert("got it 2");
}
});
var flags = new FlagList;
var addFlagView = new AddFlagView;
var flagCollectionView = new FlagCollectionView;
flags.add({key:"value"});
check the jsFiddle
Your problem is somewhere else.
If you ended up here after making the same stupid mistake I did, make sure you've got:
this.collection.bind( 'add', this.render )
and NOT:
this.collection.bind( 'add', this.render() )

access function in one view from another in backbone.js

I have this structure of views:
window.templateLoaderView = Backbone.View.extend({});
window.PopupView = templateLoaderView.extend({
initialize: function () {
this.PopupModel = new PopupModel();
this.event_aggregator.bind("tasks_popup:show", this.loadTaskPopup);
},
render: function() {
template= _.template($('#'+this.PopupModel.templateName).html());
$(this.el).html(template(this.PopupModel.toJSON()));
$('#'+this.PopupModel.containerID).html(this.el);
},
loadTaskPopup: function() {
this.PopupModel.loadTemplate("popupTask_templateHolder", "/js/templates/popup_task.html", "1", "container_dialog");
this.render();
}
});
window.TaskbarView = templateLoaderView.extend({
initialize: function () {
this.TaskbarModel = new TaskbarModel();
this.PopupModel = new PopupModel();
},
loadTaskbarPopup: function() {
this.event_aggregator.trigger("tasks_popup:show");
}
});
So I would like to runf function in one view form another. As far as I understand, I need to bind them somehow. Is it possible to bind them in initialize function?
I saw here example: Backbone.js - Binding from one view to another? . They creating both objects and than somehow binding them.
Thanks in advance,
I am kind of a fan of using the "Event Aggregator" pattern. I make sure that every view is given a copy of the same event aggregator object and they can all talk to each other through it... kind of like a CB radio :)
Do this before you create any views:
Backbone.View.prototype.event_aggregator = _.extend({}, Backbone.Events);
Now, you can publish/subscribe from anywhere:
window.PopupView = Backbone.View.extend({
initialize: function() {
_.bindAll(this, "loadTaskPopup");
this.model = new PopupModel();
this.event_aggregator.bind("tasks_popup:show", this.loadTaskPopup);
},
loadTaskPopup: function() {
// do something with this.model
}
});
window.TaskbarView = Backbone.View.extend({
loadTaskbarPopup: function() {
this.event_aggregator.trigger("tasks_popup:show")
}
});

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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