Question

So I am starting out using the play framework with Mongo and have an issue with trying to get something working using the simple MVC pattern. I can’t see the wood for the trees with this and know the solution is bound to be simple.

I have a user object defined as an entity:

package models;

import play.modules.mongo.MongoEntity;
import play.modules.mongo.MongoModel;


@MongoEntity("users")
public class User extends MongoModel
{
    public String username;
    public String email;
    public String password;
}

And I have a controller with the following two methods in it:

package controllers;

import models.User;
import play.mvc.Controller;
import play.Logger;

public class UserController extends Controller 
{
    public static void createUser()
    {
        User user = new User();
        render(user);     
    } 

    public static void insertUser(User iUser)
    {
        Logger.info("Paul 1: " + iUser + " :: " + (iUser ==  null));
    }

}

And the routes defined as follows:

POST    /insertUser    UserController.insertUser
GET     /users         UserController.createUser

So I have the following page view defined and when I click save, the code in the controller is telling me that the User object is null:

#{extends 'main.html' /}
#{set title:'Create User' /}
<form action="@{UserController.insertUser(user)}" method="POST"/>

    Username: <input type="text" value="${user.username}" /><br/>
    Password: <input type="text" value="${user.password}" /><br/>
    Email: <input type="text" value="${user.email}" /><br/>
    <input type="submit" value="Add User" />
</form>

I have tried a ton of permutations on the acton and can’t figure out why it is not working. Any ideas? All help is greatly appreciated, I know it is somethign stupid I am missing, it is just what.

Answer 1

I think you’re at least missing the name atrributes on the HTML forum input elements, which Play! will use to map the form values to your controller parameter(s). Try the following:

#{extends 'main.html' /}
#{set title:'Create User' /}
<form action="@{UserController.insertUser(user)}" method="POST"/>
    Username: <input type="text" name="user.username" value="${user.username}" /><br/>
    Password: <input type="text" name="user.password" value="${user.password}" /><br/>
    Email: <input type="text" name="user.email" value="${user.email}" /><br/>
    <input type="submit" value="Add User" />
</form>

Alternatively, you can use the template #{form} tag to have the templating system generate the form for you. This might also be useful to cross-check the output of the #{form} tag with your own form to see what is different.

Update: you may also have to delete the user parameter in the form action attribute @{UserController.insertUser(user)}, which would then be more like @{UserController.insertUser}.