Something like :
peer.on('open', function(id){ // this is a non jquery event listener
$('#pid').text(id);
});
With something like...this is not correct:
peer.on('open', function(id){
m('#pid',[id])
});
Is this even the right approach? Should I be establishing a controller and model before I attempt to convert from jquery?
More details:
I am trying to rewrite the connect function in the PeerJS example: https://github.com/peers/peerjs/blob/master/examples/chat.html
If your event listener is something like websockets, then the event happens outside of Mithril, which means you need to manage redrawing yourself. This is what you'll need to do:
Store your data in an independent model
Use that model when rendering your Mithril view
On the open event, update your model, then call m.redraw()
Conceptual example:
var myModel = { id: 'blank' }
var MyComponent = {
view: function () {
return m('#pid', myModel.id)
}
}
m.mount(document.getElementById('app'), MyComponent)
// This happens outside mithril, so you need to redraw yourself
peer.on('open', function(id) {
myModel.id = id
m.redraw()
})
In Mithril, you should not try to touch the DOM directly. Your event handler should modify the View-Model's state, which should be accessed in your View method. If you post more code, I could give a more detailed explanation of how it pieces together.
Here is a bare-bones example that shows the data flowing through Mithril. Your situation will need to be more complicated but I'm not currently able to parse through all of that peer.js code.
http://codepen.io/anon/pen/eNBeQL?editors=001
var demo = {};
//define the view-model
demo.vm = {
init: function() {
//a running list of todos
demo.vm.description = m.prop('');
//adds a todo to the list, and clears the description field for user convenience
demo.vm.set = function(description) {
if (description) {
demo.vm.description(description);
}
};
}
};
//simple controller
demo.controller = function() {
demo.vm.init()
};
//here's the view
demo.view = function() {
return m("html", [
m("body", [
m("button", {onclick: demo.vm.set.bind(demo.vm, "This is set from the handler")}, "Set the description"),
m("div", demo.vm.description())
])
]);
};
//initialize the application
m.module(document, demo);
Notice that the button is calling a method on the View-Model (set), which is setting the value of a property (vm.description). This causes the View to re-render, and the div to show the new value (m("div", demo.vm.description())).
Related
I'm having a problem where render is being called autimatically in my Marionette CompositeView which is correct, the problem is that I'm fetching collection data in the initialize and want this to be present when the render happens. At the moment I'm running this.render() inside the done method of the fetch which re-renders but this causes problems as now I have 2 views per model. Can anyone recommend how I can properly prevent this initial render or prevent the duplicate views. 1 entry will output view1 and view2.
JS CompositeView
initialize: function() {
var self = this;
this.teamsCollection = new TeamsCollection();
this.teamsCollection.fetch().done(function() {
self.render();
});
},
First of all, I don't believe there is a way to stop rendering outright, but you have a bunch ways around that.
Option 1: fetch data first, then create your view and pass data into it when it's done.
//before view is rendered, this is outside of your view code.
var teamsCollection = new TeamsCollection();
teamsCollection.fetch().done(function(results) {
var options = {res: results};
var myView = new CompositeView(options);
myView.setElement( /* your element here */ ).render();
});
Option 2:
// don't use render method, use your own
initialize: function() {
var self = this;
this.teamsCollection = new TeamsCollection();
this.teamsCollection.fetch().done(function() {
self.doRender();
});
},
render: function(){}, // do nothing
doRender: function(){
// override render here rather than using default
}
Option 3: (if using template)
// if you have a template, then you can simply pass in a blank one on initialization
// then when the fetch is complete, replace the template and call render again
initialize: function() {
var self = this;
this.template = "<div></div"; // or anything else really
this.teamsCollection = new TeamsCollection();
this.teamsCollection.fetch().done(function() {
self.template = /* my template */;
self.render();
});
},
In reality I need more info. How is the view created? is it a region? is it added dynamically on the fly? Do you use templates? Can you provide any more code?
I am trying to access an object(this.historyComboBox) declared in a view(StatusView)'s render function and trying to access the same object from another view(HistoryView)'s extendedEvents function.
I have tried to use this.historyComboBox to access it but unable to hold any reference. Got really puzzled. If anyone has got some different idea I am ready to try it out!
Note: StatusView gets initialized prior to HistoryView.
Following is the code snippet.
StatusView = Backbone.View.extend({
init: function() {
//some code
},
render: function() {
this.historyComoBox = new sys.ComboBox();
}
}
HistoryView = Backbone.View.extend({
template: _.template(historyTemplate),
init: function() {
//some code
},
extendedEvents: {
'click #refreshButton': function() {
//want to access historyComoBox; not accessible with 'this.historyComoBox'
}
}
}
To get a property of a StatusView instance, you need a reference to that instance. So, if you have something like this:
var statusView = new StatusView();
Then from within the methods of HistoryView, you can do this:
statusView.historyComboBox;
However, while you can do it this way, I wouldn't access the StatusView instance directly like this. A better way would be to pass it to the HistoryView instance as a parameter, which you would receive in the initialize method. This keeps the views loosely coupled,
var HistoryView = Backbone.View.extend({
initialize: function (options) {
this.statusView = options.statusView;
},
events: {
'click #refreshButton': function () {
// use this.statusView;
}
}
});
(I notice you're using the names init and extendedEvents. You don't mention that you're using a third-party library with Backbone or something else that might change those, so I'll just mention that Backbone expects these to be initialize and events respectively.)
Trying to learn Backbone and hitting a stumbling block when trying to fetch data, I fetch the data fine from with my view SearchBarView but once the data has been fetched I don't know how I can get this data in my SearchResultsView in order to template out each result?
Sorry if this sounds a little vague, struggling to get my head around this at the moment so could do with the guidance!
SearchBarView
performSearch: function(searchTerm) {
// So trim any whitespace to make sure the word being used in the search is totally correct
var search = $.trim(searchTerm);
// Quick check if the search is empty then do nothing
if(search.length <= 0) {
return false;
}
// Make the fetch using our search term
dataStore.videos.getVideos(searchTerm);
},
Goes off to VideoSearchCollection
getVideos: function(searchTerm) {
console.log('Videos:getVideos', searchTerm);
// Update the search term property which will then be updated when the url method is run
// Note make sure any url changes are made BEFORE calling fetch
this.searchTerm = searchTerm;
this.fetch();
},
SearchResultsView
initialize: function() {
// listens to a change in the collection by the sync event and calls the render method
this.listenTo(this.collection, 'sync', this.render);
console.log('This collection should look like this: ', this.collection);
},
render: function() {
var self = this,
gridFragment = this.createItems();
this.$el.html(gridFragment);
return this;
},
createItems: function() {
var self = this,
gridFragment = document.createDocumentFragment();
this.collection.each(function (video) {
var searchResultView = new SearchResultView({
'model': video
});
gridFragment.appendChild(searchResultView.el);
}, this);
return gridFragment;
}
Now I'm not sure how I can get this data within SearchResultView, I think I need to trigger an event from somewhere and listen for the event in the initialize function but I'm not sure where I make this trigger or if the trigger is made automatically.
Solution 1
If dataStore is a global variable then
SearchBarView
dataStore - appears like a global variable
videos - a collection attached to global variable
then in
SearchResultsView
this.listenTo(dataStore.videos, 'sync', this.render);
Solution 2
If dataStore is not a global variable
getVideos: function(searchTerm) {
console.log('Videos:getVideos', searchTerm);
// Update the search term property which will then be updated when the url method is run
// Note make sure any url changes are made BEFORE calling fetch
this.searchTerm = searchTerm;
var coll=this; //this should refer to the collection itself
this.fetch().done(function(){
var searchResultView = new SearchResultsView({collection:coll});
searchResultView.render();
});
},
It is not 100% clear how you are initializing your SearchResultView.
But, in order to have reference to the collection, can't you simply pass in the reference to the constructor of the view. Something like this:
// In your SearchbarView
var myCollection = new Backbone.Collection(); // and you are populating the collection somewhere somehow
var searchResultView = new SearchResultView(myCollection) // you just pass this collection as argument.
myCollection.bind("change", function(){
searchResultView.parentCollection = myCollection;
}
And inside your searchResultView you just refer this collection by parentCollection for instance.
If you make it more explicit as in how these 2 views are connected or related, I may be able to help you more. But, with given info, this seems like the easiest way.
I'm trying to add an item to a collection but first I want to remove the existing one. Only one item will ever exist. I can create a new one, just not remove one. Maybe I'm doing it backwards.
This is my collection, the changetheme is the function that gets called, which works away, but can't figure out how to remove the existing one. this.model.destroy() just throws an error. Maybe i'm out of context.
bb.model.Settings = Backbone.Collection.extend(_.extend({
model: bb.model.Setting,
localStorage: new Store("rrr"),
initialize: function() {
var self = this
this.model.bind('add', this.added, this);
},
changetheme: function(value) {
var self = this
this.destroy();
this.create({theme:value});
},
}));
If it matters this is my model
bb.model.Setting = Backbone.Model.extend(_.extend({
defaults: {
theme: 'e'
},
initialize: function() {
var self = this;
},
added: function(item) {
var self = this;
this.destroy();
},
}));
To remove first item from collection you can call collection.shift(), also you can just clear collection by calling collection.reset(). So in your case one could write:
changetheme: function(value) {
this.shift();
this.create({theme:value});
}
UPD
Ok, let me explain - in your example localStorage plays like any other server side. So when you call "create", then according to docs backbone instantiates a model with a hash of attributes, saves it to the server(localStorage), and adds to the set after being successfully created. That is why your collection items count increases on each page refresh. But when you call shift/remove docs then only you client side collection is affected, not the server(localStorage) one. Now the best option for you to remove model both from server and client is calling model's destroy method like that:
changetheme: function(value) {
var modelToDelete = this.at(0) //take first model
modelToDelete.destroy();
this.create({theme:value});
}
My view, TuneBook, has several child views of type ClosedTune. I also have separate full page views for each tune, OpenTune. The same events are bound within ClosedTune and OpenTune, so I've designed my app so that they both inherit from a shared 'abstract' view Tune.
To make my app more scaleable I would like the events for each ClosedTune to be delegated to TuneBook, but for maintainability I would like the same handlers (the ones stored in Tune) to be used by TuneBook (although they'd obviously need to be wrapped in some function).
The problem I have is, within TuneBook, finding the correct ClosedTune to call the handler on. What's a good way to architect this, or are there other good solutions for delegating events to a parent view?
Note - not a duplicate of Backbone View: Inherit and extend events from parent (which is about children inheriting from a parent class, whereas I'm asking about children which are child nodes of the parent in the DOM)
In your parent view (extending also from Backbone.Events), I would bind onEvent to the DOM event. On trigger, it would fire a backbone event including some "id" attribute that your child views know (presumably some row id?).
var TuneBook = Backbone.View.extend(_.extend({}, Backbone.Events, {
events: {
"click .tune .button": "clickHandler"
},
clickHandler: function (ev) {
this.trigger('buttonClick:' + ev.some_id_attr, ev);
},
}));
Child views would then naturally subscribe to the parent views event that concerns them. Below I do it in initialize passing the parent view as well as that special id attribute you used before in options.
var ClosedTune = Backbone.View.extend({
initialize: function (options) {
options.parent.on('buttonClick:' + options.id, this.handler, this);
},
handler: function (ev) {
...
},
});
You can of course also set up similar subscribers on Tune or OpenTune.
Here are a couple of possibilities.
1. Centralized: store ClosedTune objects in the TuneBook instance
Store a reference to each ClosedTune in tune_book.tunes. How you populate tune_book.tunes is up to you; since you mentioned an adder method on TuneBook, that's what I've illustrated below.
In the TuneBook event handler, retrieve the ClosedTune from tune_book.tunes by using something like the id attribute of the event target as the key. Then call the Tune or ClosedTune handler.
http://jsfiddle.net/p5QMT/1/
var Tune = Backbone.View.extend({
className: "tune",
click_handler: function (event) {
event.preventDefault();
console.log(this.id + " clicked");
},
render: function () {
this.$el.html(
'' + this.id + ''
);
return this;
}
});
var ClosedTune = Tune.extend({});
var OpenTune = Tune.extend({
events: {
"click .button" : 'click_handler'
}
});
var TuneBook = Backbone.View.extend({
events: {
"click .tune .button" : 'click_handler'
},
click_handler: function (event) {
var tune = this.options.tunes[
$(event.target).closest(".tune").attr('id')
];
tune.click_handler( event );
},
add_tune: function (tune) {
this.options.tunes[tune.id] = tune;
this.$el.append(tune.render().el);
},
render: function () {
$("body").append(this.el);
return this;
}
});
var tune_book = new TuneBook({
tunes: {}
});
[1, 2, 3].forEach(function (number) {
tune_book.add_tune(new ClosedTune({
id: "closed-tune-" + number
}));
});
tune_book.render();
var open_tune = new OpenTune({
id: "open-tune-1"
});
$("body").append(open_tune.render().el);
2. Decentralized: associate the view object with the DOM object using jQuery.data()
When you create a ClosedTune, store a reference to it, e.g. this.$el.data('view_object', this).
In the event listener, retrieve the ClosedTune, e.g. $(event.target).data('view_object').
You can use the same exact handler for ClosedTune (in TuneBook) and OpenTune, if you want.
http://jsfiddle.net/jQZNF/1/
var Tune = Backbone.View.extend({
className: "tune",
initialize: function (options) {
this.$el.data('view_object', this);
},
click_handler: function (event) {
event.preventDefault();
var tune =
$(event.target).closest(".tune").data('view_object');
console.log(tune.id + " clicked");
},
render: function () {
this.$el.html(
'' + this.id + ''
);
return this;
}
});
var ClosedTune = Tune.extend({
initialize: function (options) {
this.constructor.__super__.initialize.call(this, options);
}
});
var OpenTune = Tune.extend({
events: {
"click .button" : 'click_handler'
}
});
var TuneBook = Backbone.View.extend({
events: {
"click .tune .button": Tune.prototype.click_handler
},
add_tune: function (tune) {
this.$el.append(tune.render().el);
},
render: function () {
$("body").append(this.el);
return this;
}
});
var tune_book = new TuneBook({
tunes: {}
});
[1, 2, 3].forEach(function (number) {
tune_book.add_tune(new ClosedTune({
id: "closed-tune-" + number
}));
});
tune_book.render();
var open_tune = new OpenTune({
id: "open-tune-1"
});
$("body").append(open_tune.render().el);
Response to comment
I considered option 1 but decided against it as I already have a collection of tune models in the tunebook and didn't want another object I'd need to keep in sync
I guess it depends what kind of housekeeping / syncing you feel the need to do, and why.
(e.g. in TuneModel.remove() I would need to remove the view from tunebook's list of views... would probably need events to do this, so an event only solution starts to look more attractive).
Why do you feel that you "need to remove the view from tunebook's list of views"? (I'm not suggesting you shouldn't, just asking why you want to.) Since you do, how do you think #ggozad's approach differs in that respect?
Both techniques store ClosedTune objects in the TuneBook instance. In #ggozad's technique it's just hidden behind an abstraction that perhaps makes it less obvious to you.
In my example they're stored in a plain JS object (tune_book.tunes). In #ggozad's they're stored in the _callbacks structure used by Backbone.Events.
Adding a ClosedTune:
1.
this.options.tunes[tune.id] = tune;
2.
this.on('buttonClick:' + tune.id, tune.handler, tune);
If you want to get rid of a ClosedTune (say you remove it from the document with tune.remove() and you want the view object gone completely), using #ggozad's approach will leave an orphaned reference to the ClosedTune in tune_book._callbacks unless you perform the same kind of housekeeping that would make sense with the approach I suggested:
1.
delete this.options.tunes[tune.id];
tune.remove();
2.
this.off("buttonClick:" + tune.id);
tune.remove();
The first line of each example is optional -- depending if you want to clean up the ClosedTune objects or not.
Option 2 is more or less what I'm doing right now, but (for other reasons) I also store the model as a data attribute on view.$el, and I can't help feeling that there's got to be a better way than storing references all over the place.
Well, it ultimately comes down to your preference for how to structure things. If you prefer storing the view objects in a more centralized fashion, you can store them in the TuneBook instance instead of using jQuery.data. See #1: Centralized.
One way or another you're storing references to the ClosedTune objects: using jQuery.data, or in a plain object in the TuneBook, or in _callbacks in the TuneBook.
If you like #ggozad's approach for reasons that you understand, go for it, but it's not magic. As it's presented here I'm not sure what advantage is supposed to be provided by the extra level of abstraction compared to the more straightforward version I present in #1. If there is some advantage, feel free to fill me in.
Great solution I have taken from this article (#dave-cadwallader comment).
Extend an general backbone events object and store it in a reference vent:
var vent = _.extend({}, Backbone.Events);
Pass it to parent view:
var parentView = new ParentView({vent: vent});
The child view will trigger an event:
ChildView = Backbone.View.extend({
initialize: function(options){
this.vent = options.vent;
},
myHandler: function(){
this.vent.trigger("myEvent", this.model);
}
});
And the parent view is listening to the child event:
ParentView = Backbone.View.extend({
initialize: function(options){
this.vent = options.vent;
this.vent.on("myEvent", this.onMyEvent);
let childView = new ChildView({vent: this.vent});
},
onMyEvent: function(){
console.log("Child event has been ");
}
});
Disclaimer - pay attention that the vent object has to be injected to every view so you will find in this article better design patterns to make use of.