Allow to get error message for particular input(s)

[NYPD]

Or maybe some sort of functionality to display error messages somewhere else.

• initialize() should take a errorCallback function
• validate() should take a temp errorCallback function
• showErrorMessages() should take a temp errorCallback function maybe?
• getErrorMessage()
• getErrorMessages()
• getErrorMessagesAsMap()

[NYPD]

I think this is a two parter.

• Function that returns a map of input name to error message (or something like that).
• Overloaded method for validate() and showErrorMessages() that takes in a function which is used to display error messages somewhere else

[NYPD]

And a third

• Additional configuration during initialization that takes in a function

[NYPD]

Perhaps error messages should just take a generic function to deal with error messages in general

[NYPD]

The error callback function will be called on each element validated, it will be supplied the element itself and the error message regardless if it is valid or not. If it is valid, error message will be null.

This change was added in 777f929

[NYPD]

errorCallback should be renamed messageCallback