Catch Exceptions

In the Catch block we encounter two different scenarios:

• a controlled exception has been caught or

• an uncontrolled exception has been caught.

We want to treat both situations equally in the catch block.

1. Set DDP_TryCatchMessage = Document Property - Base - Try/Catch Message

2. Call The ParseExceptionMessage Script

3. Use the created Dynamic Document Properties to handle the Exception.

Create a j.Error.RESponse message as the result of an Exception

Exception Base Class

In case of an uncontrolled exception, the script passes through the Try/Catch Message in DDP_rootCause=DDP_TryCatchMessage. The property name is fix, and that is why you user-defined exception messages should contain a "rootCause" element, so that you can access the error message through that property, no matter if the exception was controlled or uncontrolled.

DDP_userMessage is set to "Something went wrong! Please contact your admin!".

The ParseExceptionMessage Script

Source Code on GitHub

The script parses an exception message (expected in [DDP_TryCatchMessage]) 
and sets well-defined document properties. If [DDP_TryCatchMessage] does not contain a
structured error Json, [DDP_TryCatchMessage] is routed to [DDP_rootCause] property.

If [DDP_TryCatchMessage] is not set the script throws an exception.

The [DDP_TryCatchMessage] must start with "Exception:" (case-sensitive) so that the script runs.
The script parses the following text into dynamic document properties as follows:

    Exception: {DDP_ExceptionType}
    {DDP_ExceptionJson}

The [DDP_ExceptionJson] is then interpreted as JSON and all elements on the first level 
will be turned into dynamic document properties, too. All nested elements are skipped when creating DDPs.
For example:
    DDP_TryCatchMessage=
        Exception: ApplicationException
        {
            "statusCode" : 404,
            "rootCause" : "Record not found!"
        } 
    
    DDP_exceptionType='ApplicationException'
    DDP_exceptionJson='{
        "statusCode": 404,
        "rootCause": "Record not found!"
    }'
    DDP_statusCode ='404'
    DDP_userMessage='Something went wrong! Please contact your admin!'
    DDP_rootCause  = 'Record not found!'