DVM – Domain Value Mapping

DVM – Domain value mapping as the name suggest is the approach of selecting values used in one domain for specific fields to the value used in other domain for same fields.

Here the column names are the different fields like Longname, Shortname, Language and Capital and these values are getting changed e.g. for each state like Karnataka or Tamilnadu

So we can think that in one domain Shortname can be used to capture State and whereas in another doimain Longname can be used to capture State but their other details will still hold true e.g. Capital or Language or any other fact

To implement such scenario in MuleSoft we have to use YAML as properties file

To Start with – we will create a mule API which will accept Longname or Shortname as input and return different information from the above table

Create a project which will accept state as query parameter

Let’s create YAML to reflect above table structure – CountryDVM.yaml

State:
    Karnataka: 
        Longname: "Karnataka"
        Shortname: "KA"
        Language: "Kannada"
        Capital: "Bangalore"
    KA: 
        Longname: "Karnataka"
        Shortname: "KA"
        Language: "Kannada"
        Capital: "Bangalore"
    Tamilnadu: 
        Longname: "Tamilnadu"
        Shortname: "TN"
        Language: "Tamil"
        Capital: "Chennai"
    TN: 
        Longname: "Tamilnadu"
        Shortname: "TN"
        Language: "Tamil"
        Capital: "Chennai"
    Andhrapradesh: 
        Longname: "Andhrapradesh"
        Shortname: "AP"
        Language: "Telugu"
        Capital: "Hyderbad"
    AP: 
        Longname: "Andhrapradesh"
        Shortname: "AP"
        Language: "Telugu"
        Capital: "Hyderbad"
    Kerala: 
        Longname: "Kerala"
        Shortname: "KL"
        Language: "Malayalam"
        Capital: "Trivandram"
    KL: 
        Longname: "Kerala"
        Shortname: "KL"
        Language: "Malayalam"
        Capital: "Trivandram"

Create a configuration properties entry to read YAML as properties file

Now we will add a transformation to create response from the YAML properties file

Dataweave:

%dw 2.0
output application/json
var inputState = attributes.queryParams.state
---
{
    (if (sizeOf(p('State.' ++ inputState ++ '.Longname') default "") > 0)
    (
        {
            Longname: p('State.' ++ inputState ++ '.Longname'),
            Shortname: p('State.' ++ inputState ++ '.Shortname'),
            Language: p('State.' ++ inputState ++ '.Language'),
            Capital: p('State.' ++ inputState ++ '.Capital')
        }
    )
    
    else 
    (
        {
            "message": "info not available"
        }
    ))
}

Advantages of having DVM approach

• If new information comes then it will be added into YAML file e.g. add states
• YAML provide a better readable structure which is more hierarchical
• If one domain retrieve the values on the basis of Longname and other on Shortname then both can use the same DVM
• If new domain comes e.g. Initials then we can extend the DVM to accommodate new domain

Now if we test this API in SOAP UI

Will get valid response for available states – Tamilnadu

states – TN

For unavailable states

Sample mule application – dvm-sample-service

Sample SOAP UI project – dvm-sample-service-soapui-project