How can I trigger a commit/save? - ember.js

Question

Users can be manipulated through form fields. But I can't figure out how I can save (commit) them. When ever I change the lastName of a User and click the save button I'll get the following error:
Uncaught Error: Attempted to handle event `save` on <App.User:ember309:1> while in state rootState.loaded.updated.uncommitted. Called with undefined
What do I have to change to save (commit) a record by clicking on the save button?
index.html
<script type="text/x-handlebars" data-template-name="users">
<table class='table'>
{{#each model}}
<tr>
<td>{{view Ember.TextField valueBinding='lastName'}}</td>
{{#with this as model}}
<td><button {{bindAttr class=":btn isDirty:btn-primary:disabled"}} {{action "save" target="model"}}>save</button></td>
{{/with}}
</tr>
{{/each}}
</table>
</script>
app.js
App = Ember.Application.create();
App.Store = DS.Store.extend({
revision: 12,
adapter: 'DS.FixtureAdapter'
})
App.Router.map(function() {
this.resource('users', function() {
this.resource('user', { path: ':user_id' })
})
});
App.UsersRoute = Ember.Route.extend({
model: function() {
return App.User.find();
}
});
App.UserController = Ember.ObjectController.extend({
save: function() {
this.commit();
}
})
App.User = DS.Model.extend({
lastName: DS.attr('string')
})
App.User.FIXTURES = [{
id: 1,
lastName: "Smith"
}]

Answer 1

You can change your code like this
<script type="text/x-handlebars" data-template-name="users">
<table class='table'>
{{#each model in controller}}
<tr>
<td>{{view Ember.TextField valueBinding='lastName'}}</td>
<td><button {{bindAttr class=":btn isDirty:btn-primary:disabled"}} {{action "save"}}>save</button></td>
</tr>
{{/each}}
</table>
</script>
that uses each model in controller and not #with this as model
And you define then an itemController
App.UsersController = Ember.ArrayController.extend({
itemController: 'user'
});
This will allow you to have the save method of the UserController called.
Finally, make sure you save your record:
App.UserController = Ember.ObjectController.extend({
save: function() {
this.get('content.transaction').commit();
}
})