I tried to implement user name displaying after log in. It displays in top menu. But top menu is getting displayed before log in, so it user name is getting cached.
I tried many approaches, and using volatile() is seems the best option, but it doesn't work. In this simple example currentTime calculates only once:
<script type="text/x-handlebars" data-template-name="application">
{{currentTime}}
</script>
App.ApplicationController = Ember.Controller.extend({
currentTime: function() {
console.log('computing value');
var time = new Date();
return time;
}.property().volatile()
});
Ember version 1.3
P.S. I prepared the gist to illustrate this issue: http://jsbin.com/OPUSoTaF/1
Actually, I can't find ANY way do display dynamic value in Ember's application template. Tried to display value from another controller using {{render}} helper, value still gets cached.
It seems that I just need to update value on ApplicationController from some other controller, and to do it in a proper way. Like this:
App.LoginController = Ember.Controller.extend({
needs: 'application',
setTime: function() {
this.get('controllers.application').set('currentTime', new Date());
}
});
The application to illustrate: http://jsbin.com/OPUSoTaF/4/edit
You can change ember properties and thus views using Handlebars {{action 'actionName'}} helper. You can add action helper to almost any UI element in your handlebars template an it is usually triggered on click. When triggered it calls actionName method on the controller.
Example:
Handlebars template:
<script type="text/x-handlebars" data-template-name="application">
<button {{action 'login'}}>Login</button>
{{loginTime}}
</script>
Controller:
App.ApplicationController = Ember.Controller.extend({
loginTime: 'User not logged in yet',
actions: {
login: function() {
// ... Do some login stuff ...
this.set('loginTime', new Date());
}
}
});
Working jsbin example is here: http://jsbin.com/udUyOXaL/1/edit
Related
I have a template called sample and I am changing the property show in the controller based on a button press. Now I want the controller to reset the property every time the template is rendered. Currently even if I go to 'next' template and come back, the property show remains true if the button on sample was pressed. I want to change this behaviour and the property show should be false by default. I know I can do this by defining a view and using the didInsertElement hook but is that the only way to do this?? Ember.js website says that Views in Ember.js are typically only created for the following reasons:
When you need sophisticated handling of user events
When you want to create a re-usable component
and I am doing none of the above. Here is some sample code:
<script type="text/x-handlebars" data-template-name="sample">
{{#if show}}
Showing stuff
{{/if}}
<button {{action changeShow}}>Change</button>
{{#link-to 'next'}} Next {{/link-to}}
</script>
<script type="text/x-handlebars" data-template-name="next">
Hello
{{#link-to 'sample'}}Back{{/link-to}}
</script>
App.SampleController=Ember.Controllers.Extend{(
show:false,
actions:{
changeShow:function(){
this.controllerFor('sample').set('show',true);
}
}
)};
you can use didTransition action which will trigger automatically once the transition happened. didTransition action
App.SampleController=Ember.Controllers.Extend{(
show:false,
actions:{
didTransition:function(){
this.controllerFor('sample').set('show',false);
},
changeShow:function(){
this.controllerFor('sample').set('show',true);
}
}
)};
You can use the renderTemplate hook for the route you're doing this in, and change the controller variable in there.
http://emberjs.com/api/classes/Ember.Route.html#method_renderTemplate
I'd do something like this:
App.PostsRoute = Ember.Route.extend({
renderTemplate: function(controller, model) {
var favController = this.controllerFor('favoritePost');
favController.set("toggle", false)
this._super()
}
});
I have a submit button with a onClick view event. This event checks a flag and depending upon the condition it will allow form submission. I'd like the submit action on the controller to be called. What is the best way to do this?
Here another solution based on the example by albertjan for the case you have to perform some logic in your View and afterwards delegate to your controller. This is the way i understood your question:
HBS:
<script type="text/x-handlebars" data-template-name="index">
<button {{action submit target="view"}} >Sumbit</button>
</script>
View:
App.ThingView = Ember.View.extend({
submit : function(){
//do the view part of your logic
var object = //do whatever you may need
this.get("controller").send("submitInController", object); //you do not have to send object, if you do not need to
}
});
Controller:
App.ThingController = Em.ObjectController.extend({
submitInController: function(model) {
// do the controller part of your logic
}
});
Note: The call from your view will also bubble up to your current route. So this is basically the same code, that ember is executing when using the action helper.
I would handle the whole event on the controller:
HBS:
<script type="text/x-handlebars" data-template-name="index">
<button {{action "submit"}}>Sumbit</button>
</script>
Controller:
App.ThingController = Em.ObjectController.extend({
submit: function() {
//handle things here!
//change the state of your object here to reflect the changes that
//the submit made so that the view shows these.
}
});
In Ember version 1.0.0, I've been having success adding actions to their own object literal in the controller.
IndexTemplate.html
<script type="text/x-handlebars" data-template-name="index">
<button {{action "submit"}}>Submit</button>
</script>
ThingController.js
App.ThingController = Ember.ObjectController.extend({
actions: {
submit: function() {
//handle things here!
//change the state of your object here to reflect the changes that
//the submit made so that the view shows these.
}
}
});
For more information, check out the {{action}} helper documentation from Ember Guides.
You can trigger an action from a view if the view uses the ViewTargetActionSupport mixin. The following example demonstrates its usage:
App.SomeController = Ember.Controller.extend({
actions: {
doSomething: function() {
alert('Doing something!');
}
}
});
App.SomeView = Ember.View.extend(Ember.ViewTargetActionSupport, {
someMethod: function() {
this.triggerAction({action: 'doSomething'});
}
});
I have just written extremly simple Ember app, built on top of the Rails app, working with Ember Data and displaying, creating and persisting just one entity type to the server. Everything with the latest tools (Ember v1.0.0-pre.4-134-gaafb5eb).
However, there is very strange problem I have encountered. My app has two views: entity list (index) and form for creating new entities. When I enter the index directly, everything displays OK. But when I go to the other view and then back to the list, the view is not rendered again. Where could be the problem?
I guess it might be caused by my (maybe incorrect) using new Ember router. So I'm pasting important (from my point of view) parts of the app here:
Router:
App.Router.map(function() {
this.resource('bands', function() {
this.route('new');
});
});
App.IndexRoute = Ember.Route.extend({
redirect: function() {
this.transitionTo('bands');
}
});
App.BandsRoute = Ember.Route.extend({
model: function() {
return App.Band.find();
}
});
App.BandsNewRoute = Ember.Route.extend({
renderTemplate : function(){
this.render('bands_new',{
into:'application'
});
}
});
Link back to list - which does not work:
App.BandsNewController = Em.ArrayController.extend({
cancel: function() {
this.transitionTo('bands');
}
});
Have a look at the whole app here: https://github.com/pavelsmolka/roommating
(It's hugely inspired by great https://github.com/dgeb/ember_data_example)
I don't believe it, but could it be bug in Ember itself?
I think your "render" call in your BandsNewRoute is messing things up.Try making things go more with Ember defaults. So I would refactor your app to do this:
(working fiddle: http://jsfiddle.net/andremalan/DVbUY/)
Instead of making your own render, all you need to do is create a "bands" template (it can be completely empty except for {{outlet}} if you want) and a "bands.index" template.
<script type="text/x-handlebars" data-template-name="application">
{{outlet}}
</script>
<script type="text/x-handlebars" data-template-name="bands/index">
<h2>Bands Index</h2>
{{#linkTo bands.new}}New Band{{/linkTo}}
</script>
<script type="text/x-handlebars" data-template-name="bands">
<h1>Bands</h1>
<p>
{{#linkTo index}}Start Again{{/linkTo}}
{{#linkTo bands.new}}New Band{{/linkTo}}
</p>
{{outlet}}
</script>
<script type="text/x-handlebars" data-template-name="bands/new">
I'm in new band!
<a {{action "cancel"}}>Cancel</a>
</script>
Your routes also clean up really nicely this way:
App.Router.map(function() {
this.resource('bands', function() {
this.route('new');
});
});
App.IndexRoute = Ember.Route.extend({
redirect: function() {
this.transitionTo('bands');
}
});
App.BandsNewController = Ember.Controller.extend({
cancel: function() {
this.transitionTo('bands');
}
});
I hope that helps!
I have the following controller:
App.ShowController = Ember.Controller.expend({
buttonTitle: 'Create'
});
And the following template show.handlebars
<a href='#'>{{buttonTitle}}</a>
but the text is not rendering. Is there a special call to access the attribute?
Normally, when a view is displayed (via the Router), the context of the view is automatically set to the controller, so there should be nothing to do special.
Here is an example, where the MyApp.IndexController is automatically set as the context of the IndexView (and its template is the index template):
MyApp = Ember.Application.create({});
MyApp.Router = Ember.Router.extend();
MyApp.Router.map(function(match) {
match('/').to('index');
});
MyApp.IndexController = Ember.Controller.extend({
buttonTitle: "create"
});
The template:
<script type="text/x-handlebars" data-template-name="index">
{{buttonTitle}}
</script>
And you could try it on this JSFiddle.
N.B.: I'm using Ember v1.0.0-pre.2-239 here. There are some changes to do for upgrading this example to master
I apologize if this has a painfully obvious answer but I am both a JS and Ember noob and I am having trouble finding a solution to what I think is a common scenario. Essentially, I have a multi-page app with html/css/js front end and a java back end with an exposed REST api. I have 1 app.js file that I include in all screens and multiple controllers, some of which only apply to individual screens.
EDIT: Forgot my question. My question is how do I delay the query to my server for my user data until my controller has an observer. Since the controller is present on multiple screens (which dont all need it) I do not want to blindly query on creation of the object since it would be wasteful. For now i have a hacky way of doing it where at the end of my inline script tag of a page I call the populate method. Below is what my code currently looks like.
Section of app.js:
App = Ember.Application.create();
User = Ember.Object.extend({
username: 'empty',
fullname: 'empty user'
});
App.UserDataSource = Ember.Object.extend({
fetchMyUser: function(callback) {
$.get('ncaa/user', function(data) {
callback(User.create({
username: data.username,
fullname: data.fullname}));
});
}
});
App.userDataSource = App.UserDataSource.create();
App.UserController = Ember.Object.extend({
content: null,
populate: function() {
var controller = this;
this.get('dataSource').fetchMyUser(function(data) {
controller.set('content', data);
});
}
});
App.userController = App.UserController.create({
dataSourceBinding: Ember.Binding.oneWay('App.userDataSource')
});
Ember.run.sync();
Section of index.html
<script type="text/x-handlebars">
Welcome, {{App.userController.content.fullname}}
</script>
....other code....
<script type="text/javascript">
$(document).ready(function() {
....other code....
App.userController.populate();
});
</script>
I am pretty sure my first steps will be modifying that handlebars template to extend Ember.View but would like to know what the community believes is the best practice. Also, is it wrong for me to try and put all of this in one app.js file? It would be ok to query on creation of my controller if it was only imported on screens that required the user to display.
The answer for my question did end up being in the Ember.View. Essentially what I do is override the init function of my view which adds the call to populate the necessary controller with data. The view is that instantiated via the handlebars template so no more unnecessary calls or hacky work around. Important changes below.
Index.html:
<script type="text/x-handlebars">
{{#view App.UserNameView }}
Welcome, {{fullName}}
{{/view}}
</script>
App.js:
App.UserNameView = Em.View.extend({
init: function() {
this._super();
App.userController.populate();
},
fullNameBinding: 'App.userController.content.fullname',
userNameBinding: 'App.userController.content.username'
});