Lesson content is currently in draft form.

If you’ve taken a break from this tutorial and exited irb, you would’ve had to go through the annoying step of re-running the require statements to bring in the HTTParty and JSON library.

Sure it’s just a copy-and-paste action. But like everything about programming, this tedious step can be abstracted out for our convenience.

Using the text editor

Remember when we installed a text-editor specific for programming (e.g. TextWrangler for OSX, Notepad++ or SciTE for Windows)? Let’s move out of irb for the moment and use the text-editor.

Hopefully you followed the instructions in the early setup chapters about setting up a working-directory. If not, now’s the time to do so. Just create a new directory somewhere convenient to get to (such as a sub-directory in your Downloads folder).

Then, in your text-editor, create a new text file and save it in your working-directory as my_code.rb

A place for all your requirements

Inside the my_code.rb file, let’s put in the boilerplate require statements:

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require 'rubygems'
require 'json'
require 'httparty'

puts "Done loading my code!"

Require your own file

Now quit out of your current irb window by typing exit.

This kicks you back to the command prompt.

At the command prompt, try to navigate to wherever your working directory was.

If you placed it in Downloads/my-working-dir, you should be able to do something like cd ~/Downloads/my-working-dir (in OS X) or cd C:\Downloads\my-working-dir (for Windows PC).

When you’re there, run irb and execute the following:

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load "./my_code.rb"

And this should print out:

#=> Done loading my code!

We’ve simply wrapped up the common libraries we use in a single file.

The keyword load is similar to require. Except that if we modify my_code.rb, load will actually re-run the code, whereas require will only do so once during an irb session.

Setting constants

Remember back in the variables chapter, how I mentioned that variables that have all-uppercase names have a special meaning?

These upppercase variables, called constants, are where we put values that we expect to access throughout our programming project (this is an exception to the scope concept we learned while writing simple methods).

What are the values that we might use in multiple parts of our program? How about where we actually get the Twitter data from?

Add this after the require statements in your my_code.rb_:

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TWITTER_DATA_HOST = "http://nottwitter.danwin.com"
TWITTER_USER_DATA_PATH = File.join(TWITTER_DATA_HOST, "users")
TWITTER_TWEETS_DATA_PATH = File.join(TWITTER_DATA_HOST, "statuses")

Now these constants will be available for use in making the data-retrieval calls. This is not actually best practices for a large programming project. But it serves our purposes for now.

Your entire my_code.rb file should look like this:

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require 'rubygems'
require 'json'
require 'httparty'


###############
# Constants
TWITTER_DATA_HOST = "http://nottwitter.danwin.com"
TWITTER_USER_DATA_PATH = File.join(TWITTER_DATA_HOST, "users")
TWITTER_TWEETS_DATA_PATH = File.join(TWITTER_DATA_HOST, "statuses")


puts "Done loading my code!"