Activerecord + WebServices - ruby-on-rails-3

I've built an app using Ruby On Rails 3, and now, as I've got more than one app that use the same models, I would like to build a third app for the model's logic, and call it from each app, in order to avoid repeating code across apps, etc.
To do that, I've thought about building a Rails app, and returning/receiving information through XML, and so far I've got no issues...until I've started thinking about ActiveRecod works directly with the database, and I no longer want that...now I want my app to call the service, and then communicate with the DB from there.
So, the question is: how can I move all the model's logic to a webservice without losing ActiveRecord magic in controllers, helpers, etc?
Thanks,
Brian

You can access the service via ActiveResource models - http://api.rubyonrails.org/classes/ActiveResource/Base.html. They mimic much of the basic ActiveRecord functionality.

Related

What is the proper way to call a Rails API from App to App

I have 2 different Rails application and I want these apps to send and receive information via an API. What is the correct way to do this?
I was trying to use this resource but I don't quite understand it: http://api.rubyonrails.org/
(I am not sure how to make the call for the different methods. Some methods show an URL which I guess I wouldn't have too much problem implementing, but what if the application is within the same server, what would be the correct way to call a corresponding API method.)
Is there a recommended beginners resource out there?
Thanks.
api.rubyonrails.org is Ruby on Rails documentation, so this is API of RoR. What you want is external HTTP, probably REST and probably JSON API.
There are many resources on building REST API's. In general you have to prepare some endpoints that application can send request to and handle responses.
Take a look i.e. on railscast about using active model serializers. This would be the part where you give other application endpoints to get or change data.
Normally you would stop here because in most cases you set API for other applications (like mobile or javascript applications). But in your case you will need something to send requests. There are many gems that allow that, but I find Faraday gem most useful.

is there a backend for recline.js built to work with rails?

Recline.js seems a great tool to display data on grids, maps, etc.
I'd like to use the grid views, but to be able to save what is displayed to the user on a database. I'm currently using rails for this project.
In the docs, they say how to code a backend to integrate with it (http://okfnlabs.org/recline/docs/backends.html) but i wonder if there's already someone working on it ( I couldn't find it on the web)
Thanks
The Backend object in Recline.js a javascript component that talks to a data source of some kind, typically a web service. The Backend component talks to the interface of that web service, and it doesn't care whether it be programmed in Ruby, COBOL or Java, as long as it knows where to get and send the data, and in what format.
So in short there isn't, and can't really be a ready Rails backend, because the implementation depends more on the specifics of your application -- how to map the data in your database (MySQL?) to a service API Recline can understand, and vice versa.
You can use SOLR with Rails, so I dont know why you couldn't utilize the Recline.js SOLR functionality to search your rails data.

What is the difference between ActiveResource and ActiveModel?

As a preface to this question: I am brand new to Rails development (and web-development in general), and some of my concerns may be unfounded, so any feedback would be very helpful.
I am attempting to make a Rails application that plugs into a RESTful API. I have been trying to determine the best way to go about this, and from what I understand, its narrowed down to making my own model from the ground up, utilizing ActiveModel, or utilizing ActiveResource.
It is unclear to me the advantages/disadvantages of each, and to be frank, I do not yet fully understand the difference between ActiveModel and ActiveResource. Can somebody provide me with insight regarding these three options and what makes the most 'sense' in a ror context? Thanks!
The best answer wouldn't just say "Use ActiveModel", or "Use ActiveResource" with instructions on doing so, however that would be helpful as well. I would really appreciate an answer explaining why I should use that thing, etc.
A few constraints I am dealing with are that I need to be using a key when I call the API, and a good number of the API calls will contain additional parameters.
So the key to choosing which package to use here is whether:
You are RETRIEVING data from the web API and want to
store/manipulate on YOUR server, or
You are MANIPULATING data via the web API and don't intend on storing anything on your server.
If #1, you'll need ActiveRecord, as it's Rails' package for manipulation and storage of data on your Postgres/MySQL/etc database.
If #2, you can use ActiveResource exclusively, which will let you retrieve data from the web API, work with it at runtime, and then make changes by posting back to the web API.
Many applications though, will often use both of these packages. ActiveResource to grab data very easily, and then applying it to ActiveRecord models (like User, or Location, etc) which you can use locally without having to grab data from the API over and over again.
To give you an example, for a service I was working on I grabbed Geolocation data from a public source (looking up coordinates for zipcodes), I then saved that data to local Location objects using ActiveRecord so I could look them up repeatedly without the delay of the Web API call. (if you're smart, you'll refresh this data from the web API from time to time)
Determining whether ActiveResource will work for you
Do the service requests conform to the documentation protocol? Look at the Expects a response of block in the Find method, for example. If so, you might be good to go without extra work.
Note: The documentation is a little out of sync with the changelog — as of Rails 3.1:
The default format has been changed to JSON for all requests. If you want to continue to use XML you will need to set self.format = :xml in the class. eg.
Also, ActiveResource has been removed entirely from the Rails 4.0 branch, so if you're looking forward to starting a new rails application and want the latest and greatest, this isn't an option at all — but all hope is not lost, there are plenty of gems that make interacting with RESTful interfaces simpler, like Faraday (full disclosure: I have not used faraday myself so can really comment on its efficacy, but I located it here, and there are a number of other options.
Note (from the same link above): Active Resource is built on a standard XML format for requesting and submitting resources over HTTP. It mirrors the RESTful routing built into Action Controller but will also work with any other REST service that properly implements the protocol. REST uses HTTP, but unlike “typical” web applications, it makes use of all the verbs available in the HTTP specification.
If the answer to the above is no (it does not conform) you'll need to write a wrapper class, see Facebooker for an example of how this is done in an actively maintained gem.
References:
Great tutorial on ActiveResource
Getting started with ActiveRecord
Keep in mind if you're just starting web development, you'll need to understand database and model basics too — you have your work cut out for you. :)
I will give it a try, and hopefully others will come and correct (or add) to it, so a better picture will exist ...
I see the following main differences between the two:
ActiceResource provides an interface to a resource that is (normally) accessible remotely by a (Rails) RESTful API. It is not stored kept locally, but read, updated, created and deleted by the API only. As Ryan Bates states it: "ActiveResource allows you to easily communicate between multiple Rails applications."
ActiveRecord (or nowadays ActiveModel) stores its record (or model) in a database locally, and allows others to access it remotely by a web interface for
Showing pages
Returning JSON maps or
Returning XML structures
Advantages and Disadvantages
To use ActiveResource, you have to check that your local Rails app can speak to the remote application, so that the RESTful API is compatible.
If both options are free to choose, here are some arguments:
ActiveResource will normally more expensive (calling a remote system costs at least more time) than ActiveModel.
ActiveModel will cost your own resources (setup of database at least), but this is normally not a burden.
So at the end, it depends on if you want to store something (ActiveModel) or only retrieve something (ActiveResource), which means you will use ActiveResource and (perhaps) ActiveMiodel.

Rails ActiveResource - Is it possible to bind only the model, and not the controller as well?

I've built a Rails app about a year ago. After a couple of months, the possibility of making it multi-platform appeared, so I had to build a RESTful service in order to re-use functionalities.
One of the things that I want with this Rails 3 app is to change it as less as possible, so, I found ActiveResource in order to bind the model, but then I figured that I also needed to create a controller for it, and I just wanted to keep using the one that belongs to my app, because I believe it will be too time consuming to move my controller's logic to the service.
Is there any way to do that?

how does rails console interact with model

I wanted to understand how rails console interacts directly with the model classes without getting routed via controllers.
And if the same mechanism can be used for integrating rails applications which are within a single enterprise.
I understand filters e.g. authentication filter will not be applied hence it may not be the right way to integrate applications but then a question raises as to what's the right place to code such logic which filter requests when there is more than one way of accessing.