Consuming an API

Often times your application will need to retrieve data from other sources. While most services are already gemified, there are times when you will be blazing new trails or simply interested in creating your own client (You know your implementation would be better).

Exercise

This week we are going to create a tool that will consume an existing API.

Goal

Create a simple client, library that allows you to iterate through the public Github gists.

$ irb

require './lib/gister.rb'

Gister.public_gists # => [ Gist<Gist#1213145>, Gist<Gist#1213122> ]

Gister.public_gists.each do |gist|
  # grab the code from each gist ...
end

Retrospective

• What did you find easier than you had initially imagined?

• What did you find more difficult?

• What method did you choose to request the data?

• How adaptable is your implementation to changing the request method?

• How adaptable is your implementation to URL scheme changes? version changes?

• What method did you choose to parse the data?

• How adaptable is your implementation to changes?

Further Exercise

Expanding on Your Success

• Using your client that you created, use that data to make an evaluation about the gist.

Hater Bot - able to pull down ruby examples and crush the souls of those that created them one gist at a time.

Hater's going to hate! ... and I hate:

line lengths over 80, any issues found by Reek, spelling errors in your comments, ...

HTTP Libraries

• Choose a different implementation method (e.g. open-uri, httparty, or faraday)

• Develop an implementation that would allow you to use either implementation

Different Modeling

• Choose a different implementation method (e.g. Classes, OpenStruct, Mash)

URLs and Versioning

• Implement helper methods that are similar to what you use in Rails (e.g. public_gists_url).

• Create an implementation that would allow you to switch out how the helper methods map to the real urls

  For example:

  Version 1 public_gists_url might return /public_gists

  Version 3 public_gists_url might return /gists/public

How'd they do it

• Compare your implementation to another implementation https://github.com/pengwynn/octokit

Now that you have some context about the API and an initial implementation. Stop and reflect on another implementation and see how they chose to solve the problem.