Grails validation error from service method - service

Question

I have a method in a service class that creates an object:
def createContent (fileName, description) {
def content = new Content(
fileName:fileName,
description:description,
).save()
}
Neither of those properties are nullable. How can I pass the validation errors back to be displayed? I've tried flash.message and render, both of which don't work from within service classes. I also tried
.save(failOnError:true)
which displayed a long list of errors.

Answer 1

Simplifying everything it should look like this.
Service method:
def createContent (fileName, description) {
//creating an object to save
def content = new Content(
fileName:fileName,
description:description,
)
//saving the object
//if saved then savedContent is saved domain with generated id
//if not saved then savedContent is null and content has validation information inside
def savedContent = content.save()
if (savedContent != null) {
return savedContent
} else {
return content
}
}
Now in controller:
def someAction = {
...
def content = someService.createContent (fileName, description)
if (content.hasErrors()) {
//not saved
//render create page once again and use content object to render errors
render(view:'someAction', model:[content:content])
} else {
//saved
//redirect to show page or something
redirect(action:'show', model:[id:content.id])
}
}
And someAction.gsp:
<g:hasErrors bean="${content}">
<g:renderErrors bean="${content}" as="list" />
</g:hasErrors>
And in general you should look through this: Grails validation doc