Vanrish Technology

Dataweave is a new data mapping tool which comes with MuleSoft 3.7 run time. Before Mule 3.7 runtime, Datamapper was there for data mapping. Dataweave inherit some of the functionality from Datamapper but due to restriction of complex mapping in Datamapper, Dataweave emerged with Mulsesoft 3.7 runtime.
There are three section of Dataweave.
1) Input
2) Output
3) Data transformation language

Data transformation language is based on JSON like language. If you are familiar with JSON, it is very easy to write Dataweave transformation logic and maintain this logic.

Here are some tips to write and maintain Dataweave transformation logic.

1)   Default Output of Dataweave Transformation is set into payload. But you can easily     change from dropdown and set this output as variable or session variable

2) Output of transformed data you can easily define in Dataweave. If you are transforming data into XML you just need to define as “ %output application/xml” without touching underline transformation logic. Same way if you are transforming your data into json or any other format you just need to define output like without touching underline transformation logic as “ %output application/json”, “ %output application/java”, “ %output application/csv”..

%dw 1.0
%output application/xml
%namespace ns0 http://schemas.vanrish.com/2010/01/ldaa
—

3)  Dataweave transformation logic gives leverage to skip any null field during data transformation. This is only declarative. Here is declaration to skipping null fields everywhere during transformation skipNullOn=”everywhere”

%dw 1.0
%output application/xml skipNullOn=”everywhere”
%namespace ns0 http://schemas.vanrish.com/2010/01/ldaa

—
4)  Dataweave transformation allows to access flowVars and sessionVars directly into transformation field.

orderParameter:{
         name:“MINOR_LI_ID”,
         value:flowVars.payloadVar.minorLiId
}

5)  Dataweave transformation reads properties value directly from properties file. You can access properties value in Dataweave like you are accessing during flow.

teamName:“$($.teameName)${teamNameSuffice}“,
  teamNameSuffice is defined in properties file.

6)  Dataweave transformation allows implementing condition logic for each field. It is very easy to implement and transform your data based on these condition logic. Here is example to implement to condition logic for field partnershipType.

partnershipType:“NEW” when $.partnership-type==”NEW”
                            otherwise “USED” when $.partnership-type==”USED”
                            otherwise “EM” when $.partnership-type==”EM”
                            otherwise “PU” when $.partnership-type==”PU”
                            otherwise “PN” when $.partnership-type==”PN”
                            otherwise $.partnership-type,
Here is another example

creativeType:“GRAPHIC” when ($.creative-type == “GRAPHIC” or $.creative-type == null)
                         otherwise “TEMPLATED_AD” when $.creative-type == “TEMP_AD”
                         otherwise “AD_TAG” when $.creative-type == “AD_TAG”
                         otherwise “”,

7)  During Dataweave transformation logic you can call global function and transform your field based on these function output. This is one of the ways you can call java object into Dataweave transformation.

Here is example
global-functions is tag for mule-config file where you can define function for entire mule flow

<global-functions>

def toUUID() {
return java.util.UUID.randomUUID().toString()
}

def getImageType(imageName) {
return imageName.substring(imageName.lastIndexOf(‘.’)+1)
}

</global-functions>

Now you can call this function inside Dataweave transformation logic.

 imageType:getImageType($.origin-name as :string) when $.origin-name != null otherwise “”,

Mulesoft application is based on flows. Every flow has their own execution time. We can calculate this flow execution is couple of ways. But Mulesoft provides one of the easy way to calculate this flow execution time by using interceptor . Timer interceptor (<timer-interceptor/>) is one of the mule interceptor to calculate Mulesoft flow execution time.

Here is flow diagram for timer-interceptor

Here is code for timer-interceptor to implement in your application

<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"       xmlns:spring="http://www.springframework.org/schema/beans"       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-current.xsdhttp://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd">

<http:listener-config name="HTTP_Listener_Configuration" host="0.0.0.0" port="8081" basePath="/demo" doc:name="HTTP Listener Configuration"/>

<flow name="muleTimerInterceptorFlow">
<http:listener config-ref="HTTP_Listener_Configuration" path="/" doc:name="HTTP"/>               <timer-interceptor/>
     <set-payload doc:name="Set Payload" value="Hello World"/>
<logger message="#[payload]" level="INFO" doc:name="Logger"/>
</flow>
</mule>

 <timer-interceptor/> tag display time in milliseconds.

You can customize flow execution time to replace <timer-interceptor/>  with  <custom-interceptor>.
In this custom interceptor you need to mention your custom interceptor java class.

<custom-interceptor class=”com.vanrish.interceptor.TimerInterceptor” />

Here is flow diagram for custom timer-interceptor

Here is mule-config.xml  code for custom timer-interceptor

<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"       xmlns:spring="http://www.springframework.org/schema/beans"       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-current.xsd
http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd">

<http:listener-config name="HTTP_Listener_Configuration" host="0.0.0.0" port="8081" basePath="/demo" doc:name="HTTP Listener Configuration"/>

<flow name="muleTimerInterceptorFlow">

<http:listener config-ref="HTTP_Listener_Configuration" path="/" doc:name="HTTP"/>

 <custom-interceptor class="com.vanrish.interceptor.TimerInterceptor" />

<set-payload doc:name="Set Payload" value="Hello World"/>
<logger message="#[payload]" level="INFO" doc:name="Logger"/>
</flow>
</mule>

Java TimerInterceptor  code for custom timer-interceptor tag

package com.vanrish.interceptor;

 

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import org.mule.api.MuleEvent;
import org.mule.api.MuleException;
import org.mule.api.interceptor.Interceptor;
import org.mule.processor.AbstractInterceptingMessageProcessor;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
* <code>TimerInterceptor</code> simply times and displays the time taken to
* process an event.

*/

public class TimerInterceptor extends AbstractInterceptingMessageProcessor

implements Interceptor {

/**

* logger used by this class

*/

private static Log logger = LogFactory.getLog(TimerInterceptor.class);

public MuleEvent process(MuleEvent event) throws MuleException {
long startTime = System.currentTimeMillis();
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Date stdate = new Date();
String start = dateFormat.format(stdate);
System.out.println(start);

MuleEvent resultEvent = processNext(event);

Date enddate = new Date();
String end = dateFormat.format(enddate);

if (logger.isInfoEnabled()) {

long executionTime = System.currentTimeMillis() - startTime;
            logger.info("Custom Timer : "+resultEvent.getFlowConstruct().getName() + " Start at "+start+" and end at "+end +" it took " + executionTime + "ms to process event ["                   + resultEvent.getId() + "]");
}
return resultEvent;
}
}