服务方法中的Grails验证错误

Question

我在服务类中有一个创建对象的方法：

def createContent (fileName, description) {
    def content = new Content(
        fileName:fileName,
        description:description,
    ).save()
}

这两个属性都不可为null。如何将验证错误传递回显示？我尝试过flash.message和render，它们都不能在服务类中工作。我也试过.save（failOnError:true）它显示了一长串错误。

Answer 1

简化一切，看起来应该是这样的。

服务方式：

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
    }
}

现在在控制器中：

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])
    }
}

还有一些Action.gsp:

<g:hasErrors bean="${content}">
   <g:renderErrors bean="${content}" as="list" />
</g:hasErrors>

一般来说，您应该仔细阅读以下内容：Grails验证文档