Omnicalc params

Dynamic web applications are more interesting than static websites for one reason: user input. Let's finally learn how to let our users give us input!

Your goal will be to build a simplified version of Omnicalc.

Here is the target you will ultimately build.

Project Specific Setup

1. Clone this project to your workspace as usual.
2. Set up the project: bin/setup
3. Start your web server: bin/server
4. Preview -> Preview Running Application
5. Navigate to the live app in Chrome — there's nothing there but the default Rails welcome screen!
6. This is a brand new, untouched Rails application. All we've done is add the instructions you're reading in this README. You could generate the exact same thing right now with the rails new your_app_name command.
7. As you work, use rails grade:all to see how you're doing as usual.

Part I: Flexible Routes

The way it should work is:

• If I visit any address of the pattern

  /flexible/square/[WHATEVER]
  

  And if put a number in the third segment of the path, I should see the square of the number.

• If I visit any address of the pattern

  /flexible/square_root/[WHATEVER]
  

  And if put a number in the third segment of the path, I should see the square root of the number.

• If I visit any address of the pattern

  /flexible/payment/[BASIS POINTS]/[NUMBER OF YEARS]/[PRESENT VALUE]
  

  I should see the monthly payment due, assuming that

  • the number in the third segment of the path is an annual interest rate in basis points, or hundredths of a percent

  • the number in the fourth segment of the path is the number of years remaining

  • the number in the fifth segment of the path is the present value

    

• If I visit any address of the pattern

  /flexible/random/[SMALL NUMBER]/[BIG NUMBER]
  

  I should see a random number that falls between the numbers in the third and fourth segments of the path.

Examples

• If I visit /flexible/square/5, I should see something like

  Flexible Square

  The square of 5 is 25.

• If I visit /flexible/square_root/8, I should see something like

  Flexible Square Root

  The square root of 8.0 is 2.83.

• If I visit /flexible/payment/410/30/250000, I should see something like

  Flexible Payment

  A 30 year loan of $250,000, with an annual interest rate of 4.10%, requires a monthly payment of $1,208.00.

• If I visit /flexible/random/50/100, I should see something like

  Flexible Random Number

  A random number between 50 and 100 is 87.

All of these should work no matter what integers I type into the flexible segments of the path.

Remember:

• Rails places all user input in the params hash.
• You can use the params hash in your actions or your views.
• Watch the server log to see what the params hash contains for any given request.

Your task: Build out flexible RCAVs so that all of these (infinitely many) URLs work.

Part II: Forms

Now, let's build something a little more realistic. We don't want to type input into the address bar; we want to type into forms!

The way it should work is:

• If I visit /square/new, I should see a form with a label and an input to enter a number. (Since we're no longer typing into the address bar, we can use decimals and are no longer limited to integers. Yay!)
  • If I submit that form, I should see the square of the number that I entered.
• If I visit /square_root/new, I should see a form with a label and an input to enter a number.
  • If I submit that form, I should see the square root of the number that I entered.
• If I visit /payment/new, I should see a form with labels and inputs to enter three values:
  • An APR (annual percentage rate). (Since our users are no longer limited to integers, we can avoid thinking in basis points. Phew!)
  • A number of years remaining
  • The principal
  • If I submit that form, I should see the monthly payment due given the values that I entered.
• If I visit /random/new, I should see a form with labels and inputs to enter two numbers, a minimum and a maximum.
  • If I submit that form, I should see a random number that falls between the numbers that I entered.

Part III: More Practice

• Add a link to each results page to go back and perform a new calculation.
• Add global navigation to get from calculator to calculator.
• Implement the following calculators (without any styling, just functionality):
  • Word Count
  • Descriptive Statistics

Stretch Goals

• Bootstrap it to make it look similar to the real Omnicalc. We've already connected bootstrap.css and Font Awesome for you, so you can just start using them.