Skip to main content

Converting json instance type and list in Playframework



I found the easiest way to convert your instance to/from json in Playframework is to use the following code:

For type instance

I'm just making use of Json.writes and Json.reads to do the dirty work.

case class CartProduct(id : String, qty : Double)

object CartProduct {

  implicit val cartProductWrites  = Json.writes[CartProduct] // convert to json 
  implicit val cartProductReads  = Json.reads[CartProduct]  // example - get from post 
 
}

The code below works too, but a bit too long for me.

implicit val cartProductReads: Reads[CartProduct] = (
  (JsPath \ "id").read[String] and
    (JsPath \ "qty").read[Double]
  )(CartProduct.apply _)

Somewhere in your controller, you might have the following code to write your instance in json format.

def getProduct(productId : String) = Action {
  val p = new Product("Demo", "Demo App", 12.0)
  Ok(Json.toJson(p))
}

To get back your instance from a HTTP post

def add = Action(BodyParsers.parse.json)
{
  request => val product = request.body.validate[Product]
  Ok("ok")
}


And finally your client side post could look something like this.


$.ajax({
  type: "POST",
  url: 'http://localhost:9000/cart/add',
  data: JSON.stringify({ 'id' : 'testg', 'qty': 12}),
  dataType: 'json',
  contentType : 'application/json'
});


For arrays


If you looking at return your product list as array, you can use Json.arr in getAll method in your controller :-

class Catalog extends Controller {

  def getAll() = Action {
    val result = getFakeProduct()
    Ok(Json.arr(result))
  }

  def getFakeProduct(): List[Product] = {
    var a = new Product("test1", "test desc", 12.0)
    var b = new Product("test1", "test desc", 12.0)
    return  a :: b :: Nil  }
}





Comments

Popular posts from this blog

Android Programmatically apply style to your view

Applying style to your view (button in this case) dynamically is pretty easy. All you have to do is place the following in your layout folder (res/layout)
Let's call this file : buttonstyle.xml
<?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_pressed="true" > <shape> <solid android:color="#449def" /> <stroke android:width="1dp" android:color="#2f6699" /> <corners android:radius="3dp" /> <padding android:left="10dp" android:top="10dp" android:right="10dp" android:bottom="10dp" /> </shape> </item> <item> <shape> <gradient android:startColor="#449def" a…

OpenCover code coverage for .Net Core

I know there are many post out there getting code coverage for .dotnetcore. I'm using opencover to address this needs.

In case, you do no want to use opencover and wanted to stick with vs2015 code coverage, you can try to copy Microsoft.VisualStudio.CodeCoverage.Shim.dll from C:\Program Files (x86)\Microsoft Visual Studio 14.0\Team Tools\Dynamic Code Coverage Tools\coreclr\ and drop it into your project "bin\Debug\netcoreapp1.0" folder.  Please note : you need to be on VS2015 Enterprise to do this. 

To get started, I guess we need to add OpenCover and ReportGenerator for our test projects, as shown in diagram below :-



When nuget packge gets restored, we will have some binaries downloaded to our machine and we going to use this to generate some statistics. I think the biggest issue is to getting those command lines work.

In dotnetcore, we run test project using "dotnet test" (assuming you are in the test project folder - if not please go there)  So we add this …

DataTable does not have AsEnumerable

I have problem locating my AsEnumerable extension method in my DataTabe (System.Data). Thank god for this post by Angel
(http://blogs.msdn.com/angelsb/archive/2007/02/23/does-not-contain-a-definition-for.aspx)

I was able to find this method once i have added reference to the following assembly.

C:\Program Files\Reference Assemblies\Microsoft\Framework\v3.5\System.Data.DataSetExtensions.dll

Try to do a dummy Build and you should be able to get it.