Grails - adding custom fields (columns) to all domain objects - automatically

Question

By default when you create a domain class, it will automatically add \"id\" and \"version\" column for all the domain classes (tables). What if I want to add a column say for e.

Answer 1

You can do this using metaprogramming. The code that adds the property should be run either in the doWithDynamicMethods closure of a plugin or from Bootstrap.groovy. If using the plugin approach, something like this should work:

def doWithDynamicMethods = {ctx ->
  application.domainClasses
        .findAll {it.simpleName.startsWith('S')}.metaClass.each {domainMetaClass ->

    Integer fooVal = 0

    domainMetaClass.getFoo = {-> fooVal}
    domainMetaClass.setFoo = {Integer newFooVal -> fooVal = newFooVal}
  }
}

The code above should add a Integer foo property to every domain class whose name starts with 'S'. I haven't tested this code, so it probably doesn't work. To see an example that you can be more confident about:

1. Find a plugin that adds that modifies domain classes (e.g. adds a field or method)
2. Download it
3. Look at the code in the plugin descriptor's doWithDynamicMethods closure
4. Copy, paste and adapt to your needs