Question

I’m just learning how the Play 2.0 framework. So I have a quite basic question: I just want to take a URL parameter and display it in the view. How do you do that?

I created the URL pattern:

GET /test/:id controllers.Application.testOutput(id: Long)

And an apporoptiate methode in Application:

public static Result testOutput(long id) {
        return ok(
                views.html.test.render(id)
        );
}

How do I call the id variable form the view? I know how to call methodes defined in the model in the view, but I don’t know how to display the id variable in the view. Is it the right way to pass the id variable to the render methode?

I’d like to understand the underlying concept, so an detailed explanation to the answer would be great!

Answer 1

Our test URL will be http://localhost:9000/greeter?message=hello and this will output a text/plain response with the content of the parameter message (ie hello). First, let’s define the route

GET     /greeter           controllers.Greeter.say(message: String)

Then, create a Greeter controller (I use Java)

package controllers;

import play.*;
import play.mvc.*;

// This lets you call the template without the views.html prefix
// import views.html.*;
import views.txt.*;

public class Greeter extends Controller {

  public static Result say(String message) {
    return ok(greeter.render(message));
  }

}

You can see that ok() calls a scala function defined in the file app/views/greeter.scala.txt Here is the content of that file (the first line defines the message parameter of type String used inside the function

@(message: String)
I'm the content. Note that you can place
anything you want here. Scala expressions
begin with the '@@' character. For example
next line contains the content of message:
@message

In this case I used .txt for file extensions because I wanted plain text response. If you want to produce HTML output, simply make a .scala.html file