overwrite renderJSON method for JSONP support

[Christian Koch]

Hello together,

instead of an easy renderJSON call I have to check in every action wether it is a JSONP call. This works with this 

    public static void index() {

       List<Note> notes = Note.findAll();

       if (request.params._contains("callback")) {

          Gson gson = new Gson();

          String out = gson.toJson(notes);

          renderText(request.params.get("callback") + "(" + out + ")");

       } else {

          renderJSON(notes);

       }

    }

Is it possible to overwrite the renderJSON() method? If I do so Play recognizes this as a new action.

Thank you

Christian

[Julien Richard-Foy]

> Is it possible to overwrite the renderJSON() method? If I do so Play
> recognizes this as a new action.

Use the @Util annotation to prevent this behavior.

[Christian Koch]

Thank you!

Is there a plan for implementing Jsonp in Play directly.

Christian

[Erwan Loisant]

On Sun, Aug 21, 2011 at 11:56, Christian Koch <koch....@gmail.com> wrote:
> Thank you!
>
> Is there a plan for implementing Jsonp in Play directly.

Not currently, but that's an interesting suggestion.

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[Christian Koch]

As far as I understand it should be possible to provide that as a Play module? perhaps with as an annotation @JsonpEnabled ;-)

Christian

[Erwan Loisant]

Well, you could provided as a module but the code is so simple that
I'm not sure it's worth the pain - you can just copy/paste the file in
all your projects.

I you want to reuse it in several controllers, you can just create a
JsonP class and use the @With annotation to include it in any
controller.

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[Christian Koch]

But if I create a controller in package controllers like this

package controllers;

import com.google.gson.Gson;

import play.mvc.*;

/**

 * Enable JSONP for Play controllers

 * @author ckoch

 *

 */

public class Jsonp extends Controller {

/**

* renders a callback function if there

* is a request parameter callback

* 

* @param o

*/

    @Util

    public static void renderJSON(Object o) {

    if (request.params._contains("callback")) {

    Gson gson = new Gson();

    String out = gson.toJson(o);

    renderText(request.params.get("callback") + "(" + out + ")");

    } else {

    renderJSON(o);

    }

    }

    

    /**

* renders a callback function if there

* is a request parameter callback

     * 

     * @param str

     */

    @Util

    public static void renderJSON(String str) {

    if (request.params._contains("callback")) {

    renderText(request.params.get("callback") + "(" + str + ")");

    } else {

    renderJSON(str);

    }

    }

}

it won't work using the @With(Jsonp.class) annotation. If I copy the two methods into my Application.java controller it works. 

Any ideas?

[Julien Richard-Foy]

You can use these static methods like this:

Jsonp.renderJSON(…)

BTW, you should set the content-type to "text/javascript" when returning jsonp.

[Christian Koch]

ok, but what's the problem with the @With annotation?

Jsonp.renderJSON(…)

BTW, you should set the content-type to "text/javascript" when returning jsonp.

Right, that's what Firebug is telling me all the day ;-)

Christian 

[Julien Richard-Foy]

> ok, but what's the problem with the @With annotation?

Actually you don’t need it. Unless I’m mistaking, Erwan?

[Roman R]

Thanks for this example!

I subclassed the Controller and simply put these methods into chain:

    public static void renderJSON(String str) {

    if (request.params._contains("callback")) {

    renderText(request.params.get("callback") + "(" + str + ")");

    } else {

    Controller.renderJSON(str);

    }

    }

Just needed Controller.renderJSON() instead of renderJSON() there.