Added isValid function in view_field
Changes done to fix checkbox(required) issue
Merged master and resolved conflicts
Removed return statment from isValid function as per comments
Fixed coffeelint error of long line
Removed return statement from isValid function
Removed extra blank line
Merge pull request #3 from adityagodbole/ci-484

Added isValid function in view_field. Changes done to add custom validation. Fixed checkbox issue related to required attribute.