I am working on an application that needs to modify the content of the navbar after login. Here's a basic sketch I put together (with some help from other samples online):
http://jsbin.com/umutag/1/ with this underlying code: http://jsbin.com/umutag/1/edit
How do I get the header view to display model data?
Should I be using a different helper for the template? (e.g. a {{view}}, {{render}}, or {{control}})
BTW, I've scoured this site and others, but most entries are a few months old and I see ember has been changing a lot since then (or I'm missing something obvious). The above example uses Ember 1.0.0 RC6.
Bryan
You ultimately want to bind the value in the controller (probably ApplicationController) that keeps track of whether the user is logged in or not. Since this is pertaining to login, you most likely have something like a SessionController that keeps track of the token. Here's one way to go about it:
App.SessionController = Em.Controller.extend({
token: null,
username: null,
isLoggedIn: function() {
return !!this.get("token");
}.property("token");
// ...
});
App.ApplicationController = Em.Controller.extend({
needs: "session",
isLoggedInBinding: "controllers.session.isLoggedIn",
usernameBinding: "controllers.session.username"
//...
});
And in your navbar in the template:
{{#if isLoggedIn}}
<li>Logged in as {{username}}</li>
<li>{{#linkTo "index"}}Home{{/linkTo}}</li>
<li>{{#linkTo "secret"}}Secret{{/linkTo}}</li>
{{else}}
<li>{{#linkTo "login"}}Log in{{/linkTo}}</li>
{{/if}}
Related
I am attempting to create a new record, however none of the data from the fields is being passed automatically, as I expected Ember to (from what I've read).
My template:
<form {{action save content on="submit"}}>
{{input value=name}}
<button type="submit"}}>Next</a>
From what I've read content is an alias for model and interchanging these makes no difference.
My route:
App.CampaignsNewRoute = Ember.Route.extend({
actions: {
save: function(campaign) {
console.log(campaign.name);
}
},
model: function(controller) {
return this.store.createRecord('campaign');
}
});
And my controller:
App.CampaignsNewController = Ember.ObjectController.extend({
pageTitle: 'New Campaign Setup'
});
When I hit 'Next' it logs undefined. Logging just the campaign shows it's an Ember model, but without the name attribute. name is defined on the campaign model. Setting the input to {{input value=content.name}} places the name attribute within the model returned, but it's still undefined. Am I missing anything in this process? The EmberJS site doesn't show how to do this, from what I can find.
--
As a side note: I was originally using App.CampaignsNewController = Ember.Controller.extend as my model was returning a hash of promises, one of which is an array and Ember didn't like me using either array or object controller. I simplified it to the above to verify it wasn't that which was causing the issue. So any solution taking this into account would be wonderful.
Edit: I can access the template fields by doing this.get('controller').get('name') but surely that is not necessary? Changing my controller to a Ember.Controller.extend also stops that from working, would love to know why. Clarification on best practice here would still be wonderful!
Edit2: this.get('controller.content').get('name') works if the controller is simply an Ember.Controller as opposed to Ember.ObjectController and the template has {{input value=content.name}}. I'll work with but hopefully someone can clarify this is the correct way.
ObjectController is the way to go here. You would have it backed by one particular model, your new model, and you would add additional properties to the controller for use in the template.
Code
App.IndexRoute = Ember.Route.extend({
actions: {
save: function(campaign) {
console.log(campaign.get('color'));
}
},
model: function() {
return Ember.RSVP.hash({
record: this.store.createRecord('color'),
all: this.store.find('color')
});
},
setupController: function(controller, model){
this._super(controller, model.record);
controller.set('allColors', model.all);
}
});
App.IndexController = Em.ObjectController.extend({
});
Template
In the template any time you want to access anything on the model backing the template, you can just access it as if the model is the current scope.
{{name}}
if you want to access any of the properties that exist on the controller you would use the property name that it is on the controller.
{{allColors.length}}
Here's an example:
<form {{action save model on="submit"}}>
Color:{{input value=color}}<br/>
<button type="submit">Next</button>
</form>
<ul>
{{#each item in allColors}}
{{#unless item.isNew}}
<li>{{item.color}}</li>
{{/unless}}
{{/each}}
</ul>
One last tip, always use getters and setters ;)
Ember Data hides the properties, they don't live right on the object, so campaign.name will return undefined forever and ever. If you do campaign.get('name') you'll get a real response.
With the example: http://emberjs.jsbin.com/OxIDiVU/792/edit
I'm getting this error:
Attempted to handle event loadedData on while in state rootState.loaded.updated.uncommitted.
My controller is really simple:
App.JudgeController = Ember.ObjectController.extend({
isEditing: false,
edit: function() { this.set('isEditing', true); },
done: function() { this.get("store").commit(); this.set('isEditing', false); }
});
I have a form hooked up, here's a simplified version:
<button class="btn btn-link" {{action 'edit'}} {{bindAttr disabled='isEditing'}}>Edit</button>
{{#if isEditing}}
{{view Ember.TextField placeholder="First Name" valueBinding="firstname"}}
<button type="button" class="btn btn-primary" {{action 'done'}}>Done</button>
{{#if isEditing}}
I have a navbar at the top. So the user can click the navbar and leave the page while they're editing, without clicking the Done button. Then if they go back to that page, they get that error that I mentioned at the beginning.
What do I do about this? I have a bunch of forms, and they all have a similar issue. Is there a best practice?
Maybe there a way to have a method on my controller called when the user navigates away? Then I could either rollback, or display a warning to the user and/or keep them from leaving.
Edit: I'm currently using RC5 of Ember.js. But I'm not opposed to upgrading it.
I'm not really in love with the willTransition solution (maybe because it's in the router, whereas right now all my logic is in the controller, and it feels a bit messy). I guess I'll see what other answers I get before I upgrade.
Maybe there a way to have a method on my controller called when the user navigates away? Then I could either rollback, or display a warning to the user and/or keep them from leaving.
Very good assumption! Indeed exactly what you mention can be done.
I don't know which ember.js version you are using, but assuming you use rc6 you should definitely check out on of the latest addition router facelift. See also here for the official release blog post. In your case especially the willTransition hook seam to be relevant, because all transitions types (URL changes and transitionTo) will fire a willTransition event on the currently active routes. This gives active routes a chance to conditionally prevent a transition to take place. One example is preventing navigation when you're on a form that's half-filled out:
App.FormRoute = Ember.Route.extend({
events: {
willTransition: function(transition) {
if (!this.controller.get('formEmpty')) {
transition.abort();
// now you can do the rollback on your models
// and with transition.retry() you can redirect the user
}
}
}
});
So basically in your case you would do a rollback on your models if the user tries to navigate away, and then redirect the user after you are done.
Hope it helps.
I would like to know what's the best way of designing the display of different representations of the same data model in Ember.js. To ask my question, I'll use the TodoMVC of Ember.JS, which has 3 representations of todo-data:
any todo, i.e. the entire todo list (TodosIndexRoute)
todos that are still active and incomplete (TodosActiveRoute)
todos that have been completed (TodosCompletedRoute)
Currently, you can see each of the 3 by clicking on the words at the bottom of the list, directing to a different URL each time. Since currently each representation has a route, it makes sense that each representation gets its unique URL. The main page displays the entire todo list (1.).
A. What is the best ember.js design to make the main page display all 3 representations (i.e. under just one URL)?
B. How about the best design that displays all 3 on the main page as well as on separate pages?
Currently I only figured out a clumsy way and made this modified TodoMVC app that shows incomplete and completed lists at the bottom of the page.
In index.html, I added new named lists:
{{#each todosactive itemController="todo"}}
{{ title }},
{{/each}}
In the js router, I copied TodosActiveRoute and TodosCompletedRoute into TodoIndexRoute, which is code duplication, very bad.
Todos.TodosIndexRoute = Ember.Route.extend({
setupController: function () {
var todos = Todos.Todo.find();
this.controllerFor('todos').set('filteredTodos', todos);
var todos_active = Todos.Todo.filter(function (todo) {
if (!todo.get('isCompleted')) {
return true;
}
});
this.controllerFor('todos').set('todosactive', todos_active);
...
});
I feel like I'm missing an elegant way of doing this, but my current ember.js knowledge is very limited. Should I use {{partial}}, {{render}}, render, or something else?
I tried {{ partial }} and {{ render }}, but I can't get them to display any data .
Thanks for helping out.
A) Ember tries to work really closely with urls. This is a good thing since if you want to share a url, the view should be consistent. The url is a powerful tool and each unique url should link to the same unique page. Having one url that links to multiple views isn't great, and certainly not shareable. If you have some time listen to some talks by Tom Dale and Yehuda Katz for an interesting overview of ember and what they're trying to do.
B) You can include different views on one page. Have a look at the guides, most notably on rendering templates and using helpers for more information on including different views under one url.
A) To display all 3 representations in one view, we actually just need the basic model in the single route. The key is for the controller to give you flavors of that model. The other important thing is to use data binding in the handlebars template. You can see the running version here.
In the IndexRoute, add a model that gets the plain todos list:
Todos.TodosIndexRoute = Ember.Route.extend({
model: function(params) {
return Todos.Todo.find();
},
...
Make a TodosListView that doesn't need to have anything:
Todos.TodoListView = Ember.View.extend();
In the controller, add 2 computed properties that returns the desired arrays:
Todos.TodosController = Ember.ArrayController.extend({
...
todosActive: function() {
return this.filterProperty('isCompleted', false);
}.property('#each.isCompleted'),
todosCompleted: function() {
return this.filterProperty('isCompleted', true);
}.property('#each.isCompleted'),
...
Finally, in the HTML template:
<script type="text/x-handlebars" data-template-name="todos">
Active:
{{#view Todos.TodoListView lalaBinding="todosActive"}}
{{#each view.lala}}
{{title}},
{{/each}}
{{/view}}
Completed:
{{#view Todos.TodoListView dataBinding="todosCompleted"}}
{{#each view.data}}
{{title}},
{{/each}}
{{/view}}
</script>
note the dataBinding.
Thanks to the folks on #emberjs irc for helping out.
I'm new at using ember, but already familiar with it, basically following some tutorials here and there and reading the api docs. But tutorials don't go too deep into more complex topics.
These are the details: I already implemented a web page that shows a list of items. The following are the relevant code excerpts from different parts of the app.
// the data model, the view and the controller
App.Item = DS.Model.extend({
name: DS.attr('string')
});
App.ItemsController = Ember.ArrayController.extend();
App.ItemsView = Ember.View.extend({ templateName: 'items' })
// in the router's corresponding route
connectOutlets: function(router) {
router.get('applicationController').connectOutlet('items', App.Item.find())
}
// in the handlebars template
<ul class="items">
{{#each content}}
<li>{{name}}</li>
{{/each}}
</ul>
The data for this list is loaded remotely via ember-data (notice the App.Item.find() call in the route's connectOutlet method above) and a handlebar template displays it, and dynamically updates the list as the data changes. Up to here this is basic ember.
Now I want to have a text field at the top of the list, and when the user types in this text field, the list should be updated, by filtering and showing only the items with a name that matches what the user is typing. The actual definition of what a matching name is, is irrelevant to this question. It could be those names that contain the typed string, or that start with it.
I know my next step is to include a textfield view on top of the list in the handlebars template:
<div class="search-bar">
{{view Ember.TextField}}
</div>
<ul class="items">
{{#each content}}
<li>{{name}}</li>
{{/each}}
</ul>
So my questions at this point are the following:
How do I refer to this text field in javascript code so I can attach a listener to it to detect when it changes?
And more importantly, what do I need to do inside this event listener so the list gets filtered?
I would like to know how to achieve it filtering data loaded locally, but also how to do it by loading the filtering data remotely everytime the user types.
I actually need to implement something slightly more complex than this, but knowing how to do this will help.
You can have a computed property on your controller that filters the content based on a text field.
App.ItemsController = Ember.ArrayController.extend({
// ...
searchedContent: function() {
var regexp = new RegExp(this.get('search'));
return this.get('content').filter(function(item) {
return regexp.test(item.get('name'));
});
}.property('search', 'content.#each.name')
});
Then you just bind your text field to controller.search. Example: http://www.emberplay.com#/workspace/2356272909
To filter data remotely you should have ember data load more items every time search changes. This can be done by sending an event to the router every time there is a change.
Trying to figure out the "ember best practices" for my app, regarding MVC. also for reference, I'm using ember-data, ember-layout, and ember-route-manager.
I'll use User as an example:
what I feel like I want to do is to get a User model from the database... then wrap it in a UserController, and set the model on a "content" property... then in a View, I want to bind to the controller for some functionality, and to the controller.content for model-level data. so a controller might look something like:
App.UserViewController = Em.Object.create({
content: userRecord,
isFollowingBinding : 'content.you_follow',
toggleFollow: function() {
make server call to change following flag
}
});
then the view could bind to the {{controller.content.name}}, or {{#if controller.isFollowing}}, or {{action "toggleFollowing" target="controller"}}
but say I get a list of User models back from the database... I feel like what should happen is that each of those models should be wrapped with a controller, and that should be returned as a list... so the view would have a list of UserControllers
Incidentally, I've done this... and it is working nicely.... except that everytime I reload the list, I wrap all of the new model objects with new controllers... and over time, the # of controllers in memory get larger and larger. on my base Controller class, I'm logging calls to "destroy", and I dont see it ever happening
when it comes to Em.View... I know that everytime it is removed from the screen, .destroy() gets calls (I am logging those as well). so if I were to move my code into a view, i know it will get destroyed and recreated everytime... but I dont feel like the functionality like toggleFollow() is supposed to be in view...
SO QUESTIONS:
is this how MVC is supposed to work? every instance of a model wrapped in a controller for that model? where there could be lots of controller instances created for one screen?
if I go down this approach, then I'm responsible for destroy()ing all of the controllers I create?
or is the functionality I've described above really meant for a View, and them Ember would create/destroy them as they are added/removed from the screen? also allowing template designers to decide what functionality they need (if they just need the {{user.name}}, theres no need to instantiate other controller/view classes... but if they need a "toggle" button, then they could wrap that part of the template in {{#view App.UserViewController contentBinding="this"}} )
I re-wrote this a few times... hopefully it makes sense....
I wouldn't wrap every user into an own controller.
Instead I would bind the user to a view, say App.UserView and handle the action toggleFollow on that view. This action will then delegate it's action to a controller which will handle the server call, see http://jsfiddle.net/pangratz666/hSwEZ/
Handlebars:
<script type="text/x-handlebars" >
{{#each App.usersController}}
{{#view App.UserView userBinding="this" controllerBinding="App.usersController"}}
{{user.name}}
{{#if isFollowing}}
<a {{action "toggleFollowing"}} class="clickable" >stop following</a>
{{else}}
<a {{action "toggleFollowing"}} class="clickable" >start following</a>
{{/if}}
{{#if user.isSaving}}saving ...{{/if}}
{{/view}}
{{/each}}
</script>
JavaScript:
App.usersController = Ember.ArrayProxy.create({
content: [],
toggleFollowing: function(user) {
user.set('isSaving', true);
Ember.run.later(function() {
user.toggleProperty('you_follow');
user.set('isSaving', false);
}, 1000);
}
});
App.UserView = Ember.View.extend({
isFollowingBinding: 'user.you_follow',
toggleFollowing: function() {
var user = this.get('user');
var controller = this.get('controller');
controller.toggleFollowing(user);
}
});