How can I have API methods in a rails app receive user input, then make calls to a web API (e.g., Twitter) instead of querying the local database within the rails app? I also would like to store the user query in the local rails database. So the workflow would be like so:
User enters a query term in the app
Store the query term in the local database
Send out a call to a web API (e.g., Twitter API) - retrieve the data
Present data from the web API
I understand how to call web APIs in Ruby, but not sure where in a Rails app I put methods to do so, and how they are linked to user input.
I am somewhat new to Rails. I have looked at many tutorials, etc., but can't seem to find any help on this topic.
You can use gems like
https://github.com/jnunemaker/httparty
https://github.com/taf2/curb
or you can do it manually
How make a HTTP request using Ruby on Rails?
Related
I have an existing web application that's developed with Ruby on Rails and PostgreSQL. I need to create a mobile application (and possibly a separate web application) using the data from that web application, so I'm looking to create an API server. Is it possible to do this without altering the source code from the original Rails/Postgres web application?
Any ideas on the best way to do this? Or can someone point me in the right direction on what to research?
To connect a new application hosted on Heroku to a PostgreSQL database hosted on Heroku just push your new application to Heroku as normal.
Then, under Settings on your new application dashboard, go into Config Variables and add a new config for DATABASE_URL. Put the value of the url for your existing database.
Your new application will need to be under the same account as your existing application. Heroku doesn't allow you to connect across accounts.
You probably want to take a look at this question for additional details.
Sounds like essentially you want to have two applications connecting to the same database offering the same methods, but respond in different formats (html vs, for example, json). One way of doing that relatively easily might be pushing another api only Rails app to heroku that connects to the same Postgres database (which was mentioned in the comments), but you would have to figure out how to handle authentication differently for your API end points. This depends on whether you are exposing these end points to the public or to something like a mobile front-end. You may want to switch to token-based authentication if you were formerly using sessions on the web-app. Once you implement secure authenticatoin for your api routes, all you have to do is make sure your methods, instead of rendering erb or haml templates, are returning raw data consumable by your intended client.
How can I access the Appery.io (or any future db) that is exposed to the REST API using RoR?
So I have an app i built using Appery.io and I also created a test app using RoR that I would like to use to pull information from the Appery.io db and display it on my RoR app.
I am somewhat familiar with REST and get the idea of what it is doing but I am not to certain on how to connect or make a connection from my RoR app to my Appery.io app. Appery.io has the following documentation for their db api, Appery.io DB API .
I have been looking around and also have seen people mention the following gems for HTTP request:
Weary
HTTParty
RestClient
Would I use one of those? I also read about using Active Resource as a possible solution?
Any help with getting started or a tutorial or article to point me in the right direction would be very helpful.
Thanks!
You won't be establishing an ongoing connection, each request/response will be a single query to your Appery DB. You authenticate those calls using a custom header with API key as defined in the documentation. There's an example using cURL that might be a good place to start playing with the API before you pull it into your RoR app. That example shows you how to get your key, too.
It looks like you can use the predefined APIs, or you can define a custom REST API associated with your Appery app? Instructions for building an API appear to be here.
Once you get the calls working from cURL (or other web request client of your choice), adding the calls to the RoR app should be more straightforward. Any of those gems could probably ease that process: I've only used RestClient personally, but found it very straightforward.
Any of those call methods (cURL, other clients, the gems, etc) will allow you specify your URI, method (e.g. GET or POST), headers, request body (where appropriate), and will allow you to examine your response. Take a look at the gem documentation to see how those map exactly - it will vary slightly from tool to tool.
If you don't have prior experience with calling external APIs, and would like a conceptual explanation, I like this article as a (very short!) beginner's guide.
I am currently have a running site. However, I need to do some task to sync some data to my friend's site.
So that, I need another app for fetching data from my running app's DB and submit data to another site using a gem call mechanize.
My problem will be:
Do I need a whole Rails app to do the job? If not, what would be the best practice in my case?
Is there any easy way for accessing my running app's DB? For now, the only thing I know is AR.
Thanks
API
What you're looking for is an API -- a way to connect to a source of data & use that data in some other application:
In computer programming, an application programming interface (API)
specifies how some software components should interact with each other
APIs are actually very simple -- you have a series of endpoints which an application can connect to, pulling data, typically as JSON objects. As noted by Rajarshi Das, these endpoints will likely be based on the RESTful resource structure
Rails
Rails, by design, is very good at providing API's:
This Railscast shows how to use the rails-api gem to create a RESTful API that your other app can connect to
I have a Heroku app with a PostgreSQL DB. Now I want to have a seperate process, possibly on a different machine, to access the DB. The suggestion on the Herkou site is actually what I wanted to do myself:
No, connecting to your database from machines outside of Heroku is not supported.
We recommend that you encapsulate data access in an API to manipulate it.
But I'm not sure how that's done best. I'd like to be able to send some JSON to the API and get back JSON as a result of that request. Like "give me all posts that are expired for a bunch of given userIds" or "update all users to be suspended if their posts contain any of the given words" in an example micropost app.
What's the best way to achieve that? Can I write an extra ruby program that is accessible via TCP and accepts JSON input? Is that even possible with Heroku? Or do I have to integrate the API into my rails app somehow? How?
Thankful for any ideas,
Tom
You will have to integrate the API to your rails app, there are many solutions for this, one of them is using a tool specialized for API building like Grape and mount it with your Rails app. This way you could have your Rails app running and also the API, both sharing the same codebase.
I am interested in deploying a Node.js along side my Rails application server. Just as a reference, I plan on using socket.IO to create a chat server, so users will be able to chat inside of my web application.
My current application uses Authlogic to authenticate users. I would like to ensure that only a user cannot read other users' messages, so I will need to authenticate the user session somehow. My Node.js will have access to my database, and I know Rails can store the sessions inside of the database, so I would like to use this feature to authenticate chat users. The problem is, I have no idea how to go about doing that. I'm not even sure what information is present in the session, and I do not know how I can use this information to authenticate a user.
Thanks in advance!
The rails session is tricky to use from other languages: it's just a serialised ruby object and pretty much the only documentation for the marshal format is the implementation/rubyspec.
However authlogic doesn't actually store anything in the session: it has a separate cookie (user_credentials by default, assuming your model is User)
The data in that cookie is "#{user.persistence_token}::#{user.id}", so you should be able to easily verify this from your js code