Best approach - letting users put their own temp. fields to see diff

rubyonrails-talk
1

Hey everyone!

I need some input on the best approach. I have a model Property that has some fields (price, down payment rate), then methods in property.rb that compute derived information (down payment amount) based on what the users input. Sounds simple enough.

I. PROBLEM Here's where I need help: I want to make a "property calculator" of sorts that takes a property, and allows users to input their numbers without overwriting the current property to see how the outcome (value) of the property/investment changes based on those numbers.

For example... the property saved in the database has a price of 100,000.00 and down payment rate of 10%. Derived information from that: down payment is 10,000.00. In the property calculator, I want to input 20% to see how the derived information will change, but I don't want to save this into the property.

II. THE WAY I THOUGHT OF DOING IT I know how to do it, but it's very tedious, and I know that once something becomes tedious in Rails and I'm probably approaching things wrong.

I was thinking of putting options in each of the methods in the Property class. For example,

def down_payment(options={})   options.stringify_keys!   dpr = options['down_payment_rate'].to_f || down_payment_rate   price * dpr end

This sounds nice and simple enough at the start but I have many of these derived methods and putting this options thing in all of them would be a hassle.

How do you suggest I approach this?

Thank you

2

Ramon Miguel M. Tayag wrote:

Hey everyone!

I need some input on the best approach. I have a model Property that has some fields (price, down payment rate), then methods in property.rb that compute derived information (down payment amount) based on what the users input. Sounds simple enough.

I. PROBLEM Here's where I need help: I want to make a "property calculator" of sorts that takes a property, and allows users to input their numbers without overwriting the current property to see how the outcome (value) of the property/investment changes based on those numbers.

For example... the property saved in the database has a price of 100,000.00 and down payment rate of 10%. Derived information from that: down payment is 10,000.00. In the property calculator, I want to input 20% to see how the derived information will change, but I don't want to save this into the property.

II. THE WAY I THOUGHT OF DOING IT I know how to do it, but it's very tedious, and I know that once something becomes tedious in Rails and I'm probably approaching things wrong.

I was thinking of putting options in each of the methods in the Property class. For example,

def down_payment(options={})   options.stringify_keys!   dpr = options['down_payment_rate'].to_f || down_payment_rate   price * dpr end

This sounds nice and simple enough at the start but I have many of these derived methods and putting this options thing in all of them would be a hassle.

How do you suggest I approach this?

Thank you

Why would anything be saved back to the database in the first place? Or are you doing the math in your app rather than doing it in JavaScript?

3

The math will be done in the app.. :slight_smile: I don't mean to save the fields into the database if it's just the calculator I'm accessing.