One of the great things about Salesforce when dealing with external webservices is being able to easily parse JSON into Apex classes. I’ve covered this in several previous posts. However a common problem is that the system you are integrating with is they may be using a variable name that is reserved. With the following data, we can see that there is a variable named “case” if we ant to parse this data into a Apex class we won’t be able to because case is a reserved name.

{
    "data": [
        {
            "case": "123456",
            "subject": "Test case"
        }, {
            "case": "789012",
            "subject": "Another case"
        }
    ]
}

In a previous post, I talked about how to pull Runkeeper data into Salesforce. The key portion of this revolved around JSON parsing of the data into Apex classes. In this post I’ll talk about how to use Object Oriented structures to extend the classes previously written to support additional data.

I have been several posts recently on the Developer Boards around JSON deserialization and some weird and convoluted ways to convert it into something that is useful for Salesforce. Let’s talk about what I have found is the cleanest way to handle JSON deserialization.

JSON Payload

Let’s take a look at our JSON payload. I am taking the payload from the docsample Heroku app since it’s an easy way to get consistent data from a webservice.

{
  "invoiceList": [
    {
      "totalPrice": 5.5,
      "statementDate": "2011-10-04T16:58:54.858Z",
      "lineItems": [
        {
          "UnitPrice": 1,
          "Quantity": 5,
          "ProductName": "Pencil"
        },
        {
          "UnitPrice": 0.5,
          "Quantity": 1,
          "ProductName": "Eraser"
        }
      ],
      "invoiceNumber": 1
    },
    {
      "totalPrice": 11.5,
      "statementDate": "2011-10-04T16:58:54.858Z",
      "lineItems": [
        {
          "UnitPrice": 6,
          "Quantity": 1,
          "ProductName": "Notebook"
        },
        {
          "UnitPrice": 2.5,
          "Quantity": 1,
          "ProductName": "Ruler"
        },
        {
          "UnitPrice": 1.5,
          "Quantity": 2,
          "ProductName": "Pen"
        }
      ],
      "invoiceNumber": 2
    }
  ]
}

So we can see here that the data provided is an invoice list and each invoice contains data and line items for that invoice.