Grails web flow | 易学教程

问题

Is there any way to pass model data to a view state? Consider the following example view state:

class BookController {
  def shoppingCartFlow = {
    showProducts {
      on("checkout").to "enterPersonalDetails"
      on("continueShopping").to "displayCatalogue"
    }
  }
}

If I want to pass the data model [products: Product.list()] to showProducts.gsp, is there any way to do this apart from preceding the view state with an action state that stores the model in flow scope?

Thanks, Don

回答1:

Hmm, it's been a bit since I did a flow, and your example is simplistic (just for being an example's sake, I hope).

What your missing is the initial action in the flow. Keep in mind that a "view" flow action as your showProducts is just says what to do when your showProducts gsp POSTS. It's the action that SENT you to showProducts that should create the model to be used in showProducts.gsp

def ShoppingCartFlow = {
   initialize {
       action {  // note this is an ACTION flow task
           // perform some code
           [ model: modelInstance ] // this model will be used in showProducts.gsp
       }
       on ("success").to "showProducts"      
       // it's the above line that sends you to showProducts.gsp
   }

   showProducts {
        // note lack of action{} means this is a VIEW flow task
        // you'll get here when you click an action button from showProducts.gsp
      on("checkout").to "enterPersonalDetails"
      on("continueShopping").to "displayCatalogue"
   }

   // etc. (you'll need an enterPersonalDetails task, 
   // displayCatalogue task, and they
   // should both be ACTION tasks)
}

Make sense?

回答2:

Maybe I don't understand the question, but can't you do

render (view:"showProducts", model:[products: Product.list()]

inside your controller?

回答3:

You can try this (assuming you want go to checkout):

showProducts {
      on("checkout"){
           // do somethings here too if you like
           // then pass your data as below:
           [products: Product.list()]
      } .to "enterPersonalDetails"
      on("continueShopping").to "displayCatalogue"
}

来源：https://stackoverflow.com/questions/1002170/grails-web-flow

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grails

groovy

spring-webflow