Question

Is it possible to inject a Spring bean into a Grails webflow? I tried the following

class CheckoutController {

    ShoppingService shoppingService

    def checkoutFlow = {
        start {
            action {
                // This attempt to access the service doesn't work
                flow.addresses = shoppingService.getOrder()
            }
        }
    }
}

I can access shoppingService from a regular controller action, but I can’t access it from an action of the webflow (see above).

Answer 1

At first I thought what you listed was pseudocode but I made a sample app using your example and got the NPE as well. I think it may be your flow structure that is the problem. action blocks should go within a flow state. Your flow definition should look something like:

class CheckoutController {
  ShoppingService shoppingService

  def checkoutFlow = {

     start {
       action {
         flow.addresses = shoppingService.getOrder()
         if(flow.addresses) {
            showForm()
         }
         else {
            showError()
         }
       }
       on("showForm").to "showForm"
       on("showError").to "showError"
     }

     showError {
        ...
     }
     //etc.
  }
}

You can definitely use injected services in your web flows. I am guessing that the problem lies in your flow structure.