Question

I am building a webservice with playframework 2 and extjs4. Until today I have managed to overcome any obstacle. But this is something I can’t deal with alone. I followed tutorial, but it didn’t help me. Well, at first it did. I know it worked, I was able to add some values to the database (mongodb). I doubt if it is important, but:

• everything worked fine, I added some test data into db
• I wrote some other methods in Java
• I used db.Category.remove() on my mongo collection
• server is unable to receive any values from form now

I have a Ext.FormPanel with 2 fields:

items: [
    { 
        id: 'categoryName',
        fieldLabel: 'Category name', 
        name: 'categoryName', 
        allowBlank: false 
    },{
        xtype: 'textarea',
        id: 'categoryDescription',
        fieldLabel: 'Description',
        name: 'categoryDescription',
        allowBlank: true
    }
]

Corresponding Model class looks like that:

@MongoCollection(name = "Category")
public class CategoryModel{
    private String categoryName;
    private String categoryDescription;

    @JsonProperty("categoryName")
    public String getName() {
        return categoryName;
    }

    @JsonProperty("categoryName")
    public void setName(String name) {
        this.categoryName = name;
    }

    @JsonProperty("categoryDescription")
    public String getDescription() {
        return categoryDescription;
    }

    @JsonProperty("categoryDescription")
    public void setDescription(String description) {
        this.categoryDescription = description;
    }

    public String toString(){
        ObjectMapper mapper = new ObjectMapper();
        String json = null;
        try {
            json = mapper.writeValueAsString(this);
        } catch (JsonGenerationException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (JsonMappingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return json;
    }
}

And finally, here’s where I want to receive values:

Form<CategoryModel> categoryForm = form(CategoryModel.class);
System.out.println(categoryForm);

Output from Play console:

Form(of=class kunto.models.CategoryModel, data={}, value=None, errors={})

Firebug shows that POST values are being sent correctly:

categoryDescription test
categoryName    test

And I have POST request type in conf/routes defined on the server side for this particular request.

I have 2 questions:

• what to do to fix it?
• more importantly, why did it happen?

EDIT
As @adis suggested:

Form<CategoryModel> categoryForm = form(CategoryModel.class).bindFromRequest();
System.out.println(categoryForm);
System.out.println(categoryForm.data());

outputs:

Form(of=class kunto.models.CategoryModel, data={categoryName=test, categoryDescription=test}, value=Some({"categoryName":null,"categoryDescription":null}), errors={})
{categoryName=test, categoryDescription=test}

I also checked

CategoryModel categoryModel = form(CategoryModel.class).bindFromRequest().get();
System.out.println(categoryModel);

it outputs: {"categoryName":null,"categoryDescription":null}

Anyone can explain this?

Answer 1

As commented you have to bind the request to a model by:

 Form<CategoryModel> categoryForm = form(CategoryModel.class).bindFromRequest();

This will allow you do also checks on the properties in you model if you have defined them, like: @Contraints.Required.

After the binding, you get the form object and get the model instance:

CategoryModel newCatModel = categoryForm.get();

This should give you an instance of your model populated with the data from your post reqeust. Usually this method looks like:

Form<Task> taskForm = form(Task.class).bindFromRequest();

if (taskForm.hasErrors()) {  // check for constraints
    Logger.info("Error:" + taskForm);
    return badRequest(views.html.task.create.render(taskForm));
}
// here get the model instance
Task newTask = taskForm.get();

Hope this helps.