Try use JavaScript scripting instead of Groovy scripting in your CPI project

Dear CPI folks,

We used to write Groovy scripting in our CPI integration projects. But if you are a big fan of JavaScript like me, why not to use JavaScript to write the script in your next CPi integration project?

Unfortunately by searching on SAP community, it is very hard to find any resource on how to do that. With some research on this topic, I managed to test successfully with JS script powerned iFlow. That’s the reason why I want to share my findings in the community.

Background

Based on SAP Help Portal document: https://help.sap.com/docs/cloud-integration/sap-cloud-integration/define-local-script-step. The scripting engine that was used in CPI runtime environment is so called ‘Rhino‘.

It is very easy to find the home of this Rhino engine on the Internet: https://github.com/mozilla/rhino/. The README document is showing very clear information that the Rhino is “an implementation of JavaScript in Java“.

The API document is here: https://javadoc.io/doc/org.mozilla/rhino/1.7R4/index.html

Local Test Environment

It is always joyful that we can play around with scripting locally before using it officially in our project.

To prepare a playground on your local environment. Download the jar file from https://mvnrepository.com/artifact/org.mozilla/rhino/1.7R4, put it in somewhere on your PC. And then use the command line “java -jar rhino-1.7R4.jar -debug -version 180” to start the shell to test.

Rhino Shell in Command Line

I still haven’t figure out what is the difference between these possibile version no: -version 100|110|120|130|140|150|160|170|180. But from the screenshot above you can see, “help()” is very useful to get some idea on how to setup the shell environment and version() will give you exactly what you set for the version.

java -jar rhino-1.7R4.jar -f <filename of your rhino js file>

CPI iFlow Implementation:

Now let’s implement some simple CPI scripting features in the iFlow:

When you select “JavaScript” as the scripting language in CPI iFlow design, you will see the template that SAP has prepared for you, so you don’t have to build the wheel again.

overview of the iFlow design

In my test iFlow design,

• The iFlow will be triggered only once by Timer so that the test can be triggered/managed by deployment on demand.
• The XML payload was generated by a SFAPI (SOAP) query to the Compound Employee entity of sandbox SFSF tenant.
• I chained two scripts (JS and Groovy) in order to get the logging message to compare the results.
• The XML Modifier is used to remove the XML head from the payload so that your JS script can work without any issue.

Note:

I tried to use Regular Expression in JS to replace(remove) the XML head but unfortunately that was failed with the error “The choice of Java method java.lang.String.replace matching JavaScript argument types (function,string) is ambiguous; candidate methods are: class java.lang.String replace(char,char)”). I guess that was caused by the supportability of the RegEx in Rhino. As long as the XML modifier can do the trick, I don’t care about it anymore.

payload = payload.replace(/<\?xml[^>]*\?>/, "");

The script itself is very straight forward. The only thing that I want to mention is that the Rhino JS engine supports the ECMAScript for XML (E4X) which is an extension to provide the native support of XML in Rhino.

So you can easily access the XML payload with single line of code, but please bear in mind if you use “typeof parsedPayload” to check the object type, it is “xml” instead of “object“.

const parsedPayload = new XML(body);

you can get more details about this topic from here: https://svn.wso2.org/repos/wso2/tags/carbon/0.1alpha/mashup/java/xdocs/e4xquickstart.html#modifying

Source Code of my script:

/* Refer the link below to learn more about the use cases of script.
https://help.sap.com/viewer/368c481cd6954bdfa5d0435479fd4eaf/Cloud/en-US/148851bf8192412cba1f9d2c17f4bd25.html

If you want to know more about the SCRIPT APIs, refer the link below
https://help.sap.com/doc/a56f52e1a58e4e2bac7f7adbf45b2e26/Cloud/en-US/index.html */
importClass(com.sap.gateway.ip.core.customdev.util.Message);

function processData(message) {
    //Body
    var body = message.getBody(java.lang.String);
    const payload = new XML(body);
    
    const counter = payload.CompoundEmployee.length();
    
    const firstElement = payload.CompoundEmployee[0];

    const messageLog = messageLogFactory.getMessageLog(message);
    if(messageLog != null){
        messageLog.setStringProperty("JS Logger", "Logger")
        messageLog.addAttachmentAsString("JavaScript MessageCounter", counter, "text/plain");
        messageLog.addAttachmentAsString("JavaScript First CompoundEmployee", firstElement , "text/plain");
     }
    
    return message;
}

After deployment of the iFlow, I got the successfully result as expected. The total number of Compound Employee records and the first employee payload appear in the attachment.

Counter:

First Employee Payload:

Simple like that !

With the power of JavaScript native JSON support, you may get more from the JSON based integration scenarios with JSON.parse and JSON.stringify.

I hope this blog can inspire you on using Java Script as the scripting language in your next project. Enjoy it. 🙂

Thank you

Best Regards
Lionel