grails - 无法在网域类别中使用Grails g.link

Question

我在返回URL的域类中有静态方法。我需要动态生成该url，但g.link无法正常工作。

static Map options() {
    // ...
    def url = g.link( controller: "Foo", action: "bar" )
    // ...
}

我收到以下错误:

Apparent variable 'g' was found in a static scope but doesn't refer to a local variable, static field or class. Possible causes:
You attempted to reference a variable in the binding or an instance variable from a static context.
You misspelled a classname or statically imported field. Please check the spelling.
You attempted to use a method 'g' but left out brackets in a place not allowed by the grammar.
 @ line 17, column 19.
           def url = g.link( controller: "Foo", action: "bar" )
                     ^

1 error

显然我的问题是我正在尝试从静态上下文访问 g，那么我该如何解决呢？

Answer 1

g对象是一个标记库，它在域类中不可用，就像在 Controller 中一样。您可以通过grailsApplication来获得它，如下所示:How To Call A Taglib As A Function In A Domain Class

在Grails 2+中执行此操作的更好方法是通过grailsLinkGenerator服务，如下所示:

def grailsLinkGenerator

def someMethod() {
    def url = grailsLinkGenerator.link(controller: 'foo', action: 'bar')
}

在这两种情况下，您都需要做一些额外的工作才能从静态上下文中获取 grailsApplication/ grailsLinkGenerator。最好的方法可能是从您的域类的 domainClass属性中获取它:

def grailsApplication = new MyDomain().domainClass.grailsApplication
def grailsLinkGenerator = new MyDomain().domainClass.grailsApplication.mainContext.grailsLinkGenerator