RESTAdapter vs Localstorage. Why should I switch to RESTAdapter? - ember.js

Question

I've been working with Ember for several months now. Our project had to run offline so we used App Cache and Ember Localstorage Adapter. I've become very comfortable with this approach. We load all data at once from the server and then use it throughout the project's Routes.
Currently we must build the Admin Panel for our project. It is not required to work offline. I thought I might give Ember's RESTAdapter a try since it seems to be the most popular way of working with data.
At first impression it seems to me that it makes things more complicated.
For example (and I'll oversimplify things for the sake of the example), I have 2 entities:
App.User = DS.Model.extend({
firstName: DS.attr('string'),
lastName: DS.attr('string'),
phoneNumber: DS.attr('string'),
studies: DS.hasMany('study')
});
App.Study = DS.Model.extend({
name: DS.attr('string'),
description: DS.attr('string'),
});
And the rotues
App.UsersRoute = Ember.Route.extend({
model: function(){
return this.store.find('user');
}
});
App.UserRoute = Ember.Route.extend({
setupController: function (controller, model) {
var userId = model.get('id');
this._super.apply(this, arguments);
this.store.find('user', userId).then(function (user) {
controller.set('user', user);
});
}
});
On the /users route I show only the users basic info.
On the /user route I show his info and the studies to which he is assigned to.
This means the if the user moves from /users to /user route using a transitionTo, the user template will receive the user model from the in memory data store. Still, there are no studies loaded yet and won't be able to show them. Eventually, we must sideload the studies models once with the users.
If the /user route is accessed directly from the browser's URL or a page refresh occurs then the server must provide the user model with the studies sideloaded once again.
So on the server side we must implement two controller methods which must return something like this.
/users route:
`{
"users":[{/*user1*/},{/*user2*/}],
"studies":[{/*study1*/}, {/*study2*/}, {/*study3*/}]
}`
/user route -
{
"user":{/*userdata*/},
"studies":[/*and array of studies*/]
}
Considering that we don't use big sets of data. Supposingly up to 20 users and up to 20 studies, why shouldn't I load them at once and store them using the localstorage adapter (in order to keep the data safe from page refresh) and use RESTAdapter?
It seems to me that by using RESTAdapter, we must write much more code on the server side and most importantly the user experience will be affected. Most of the time when a route will be accessed there will be a delay of a few seconds while the request makes its roundtrip to the server and back.
Please share your opinion. Why use RESTAdapter if there are no large data sets? How big should the data set be in order to be forced to use RESTAdapter? Are there any other advantages over localstorage?

Answer 1

You can always push everything you need into the store (using push, pushMany or pushPayload), in this case you don't have a big amount of data, so its not a big deal, but you will still have to fetch it at least one from the server, which is your source of truth.
But since this is the admin panel, I guess you are not only displaying data, but also updating and probably deleting, so you will have to still implemenet the methods to handle that on the server side, and REST is the standar approach to do that, but ember does not force you to use it, if you want you can alwasy do $.post (not recommended).
You also don't need to side load everything, you could define your relationshipt async
studies: DS.hasMany('study', {async:true} )
And then ember would first hit /user and then /studies/{id} for each study related to that user.
See the guide for more information.