Question

Here’s what I am trying to do: The user enters a string. The string contains 2 parts and will look like this:

{EventClass: someMethod=>arg1, arg2, arg3....}, {Action: someMethod=>arg1, arg2, arg3....}

A concrete example of this would be:

{TwitterEvent: newTweet=>arg1, arg2, arg3....}, {PersistenceAction: saveToHardDrive=>arg1 arg2...}

Then I will parse this string, instantiate an instance of TwitterEvent, call that method on it. Then do the same thing for PersistenceAction

What the best “design” for this type of application? How would I dynamically instantiate classes from parsed string and then call method? And potentially, the method will have arguments? How would I detect/handle errors?

Answer 1

Get class object from name string:

 Kernel.const_get('TwitterEvent')

Invoke arbitrary method on object:

 event.send(:new_tweet)

The rest is up to you. 🙂