Grails: How to dynamically change method signature in scaffolded code depending on Domain id type?

Question

I'm trying to build a grails (2.1.0) application on top of a legacy database. It has a ton of tables, and I'd like very much to use only dynamic scaffolding. The issue is that some of the tables have a string as primary key, but template code in src/templates/scaffolding/Controller.groovy for e.g. show is

def show(Long id) {
    def ${propertyName} = ${className}.get(id)
    if (!${propertyName}) {
        flash.message = message(code: 'default.not.found.message', args: [message(code: '${domainClass.propertyName}.label', default: '${className}'), id])
        redirect(action: "list")
        return
    }

    [${propertyName}: ${propertyName}]
}

For the string keys, this seems to turn the string into null, and the get fails with the error $Domain not found with id null.

If I run a generate-controller and change the signature to def show(String id), it works as expected.

So, is there a way to inspect the domain class at "dynamic scaffolding time" and write the method accordingly?

Answer 1

Within the controller template you have a domainClass variable that gives you access to the GrailsDomainClass representing the class for which you are generating the controller, so you can do something like this (and likewise for edit, update and delete):

def show(${domainClass.identifier.type.name} id) {

which should generate def show(java.lang.Long id) or def show(java.lang.String id) as appropriate.