Helper Methods

The starting point of this project is where we left the ad2-getting-started project at the end of class on Day 1.

Setup

bin/setup

Write some tests

We're going to be learning a lot of ways to improve our code, while holding functionality constant.

That means we're going to need to do a lot of testing to make sure we didn't break functionality as we evolve our code. Once you get tired of manually clicking through every link, form, etc, consider writing some automated tests to save yourself the trouble.

Read Sections 1, 2, 4, 5, 6, and 7 of the Rails Guide on Testing. These are the kinds of tests that we write most frequently.

In this project, we have one fully functional web resource, movies. Create a test file, test/system/movie_test.rb, and take a stab at writing some System tests in it to lock down the current functionality of the application. For example, try adding a test that checks to make sure the URL /movies has an <h1> on it containing the copy "List of all movies". Run your tests with:

rails test test/system/movie_test.rb

After you’ve spent 20-30 minutes on it, you’re allowed to look at the example specs in test/system/example_specs.rb. You can copy-paste some or all of them into your own test file and run then periodically as you’re doing the rest of the project to ensure you didn’t break anything as we refactor.

Walkthrough Video

There's a walkthrough video to go along with this project on Canvas.

Clean-ups that we already know how to do

• Anywhere you see the old Hash syntax (:symbol keys with hash rockets =>): switch to the new Hash syntax.
• Anywhere you see optional curly braces around Hash arguments: remove them.
• Where possible, drop render statements.
• When providing keys to params, use Symbols. (Unlike with most hashes, you can use Strings and Symbols interchangeably as keys to params.)

Refactor routes

• Re-write routes using more succinct forms of get, post, patch, delete, and, ultimately, resources.

First new helper methods

• Replace all references to URLs outside of config/routes.rb with route helper methods.
• Replace all <a> elements in view templates with link_to methods.

Forms in general

• Replace all <form> elements in view templates with form_with methods.
• Replace all <input> elements with text_field_tag, number_field_tag, text_area_tag, etc.

Forms specifically for model objects

• Change the names of inputs so that values in the params hash are nested within an inner hash.
• Assign all of the values at once using ActiveRecord's mass assignment ability via new or update.
• Whitelist which attributes you want to allow to be mass assigned from params with params.require(:movie).permit(:title, :description).
• Switch from form_with(url:) to form_with(model:)
• Switch from text_field_tag, etc; to form.text_field, etc.
• Move form to partial and re-use wherever possible.