Grails: Unable to get model data from controller to view

I have been using Grails for last 3 weeks (learning and working). I have been working on porting a JSP/Servlet application to Grails and it has been absolute "fun" porting the application.

I have facing an issue and have been searching, reading but could not solve it yet.

In the GSP page I have a textfield and search button where user enters ProductID. I have a controller which is called from jQuery Ajax method when a search button is clicked.

 // ----- Part of jQuery Ajax call ---
$.ajax({
        type : "post",
        url : '/${grailsApplication.metadata['app.name']}/product/checkProductAjax',
        data : "pid="+proID,

// ----- Contoller code-----
class ProductController {
      def scaffold = true    
          def checkProductAjax = {
                 def product= Product.findByProductId(params.pid)
                if(product) {
                     [product: product] // model to get data in GSP page.                  
                      render(product.toString() + ":" + product.id)
                } else {
                    render("none")
                }
          }
}

Ajax call and everything works fine. The pr开发者_如何学Coblem I am facing is how to get the model (i.e. the Product data back to the GSP page i.e. [product: product] and display in GSP as for e.g. Product Name: ${product}

How can I get it working? I have read examples where it is mentioned that just setting the model [product: product] will help to get the data in GSP.

Product Name: ${product} always shows blank in the GSP page Product Name:

Please tell me what I am doing wrong.

Cheers! Jay Chandran

[product: product] and render(product.toString() + ":" + product.id) are incompatible. When you see a controller action whose last line is a map like [product: product] this is the implicit return value since it's the last statement of the action closure - it's the equivalent of return [product: product]. But if you have a map in the middle of a method it's just created and discarded. It's pretty much equivalent to

def ignoreThisMap = [product: product]
// other code

Since you're making an Ajax call though, putting the product in the model doesn't make sense since you aren't going to re-render the GSP. You're going to render text, JSON, XML, or some other content that the client-side JavaScript will use to update some subset of the html. So you probably want something closer to

if (product) {
   render product as JSON
}
else {
   render "none"
}

and then you can use jQuery or Prototype to evaluate the JSON and extract the data in your JavaScript.

you probably want to use the grails tags that are created for this type of work; it wraps the AJAX code all up for you

http://www.grails.org/Ajax