Merge Array object elements using comparison - wso2

Question

We have a requirement where we need to feed data into an empty json array element from another array object using element comparison.
The sample payloads and required results are mentioned below for better understanding.
Payload1: (Input Payload)
{
"data": [
{
"name":"ram",
"eno":"100",
"dept":"Sales",
"sal":null
},
{
"name":"gopal",
"eno":"101",
"dept":"Sales",
"sal":null
},
{
"name":"hari",
"eno":"102",
"dept":"Sales",
"sal":null
},
{
"name":"pankaj",
"eno":"103",
"dept":"Sales",
"sal":null
},
{
"name":"raju",
"eno":"104",
"dept":"Sales",
"sal":null
}
]
}
Payload2: (Response From a third party webservice)
{
"data": [
{
"eno": "100",
"sal": 2000
},
{
"eno": "101",
"sal": 2300
},
{
"eno": "102",
"sal": 1800
},
{
"eno": "104",
"sal": 2500
}
]
}
Required Result:
{
"data": [
{
"name":"ram",
"eno":"100",
"dept":"Sales",
"sal":2000
},
{
"name":"gopal",
"eno":"101",
"dept":"Sales",
"sal":2300
},
{
"name":"hari",
"eno":"102",
"dept":"Sales",
"sal":1800
},
{
"name":"raju",
"eno":"104",
"dept":"Sales",
"sal":2500
}
]
}
.................................................................

Answer 1

Here is how you can do this by only using synapse. I hardcoded the second response.
<?xml version="1.0" encoding="UTF-8"?>
<api context="/HelloWorld" name="HelloWorld" xmlns="http://ws.apache.org/ns/synapse">
<resource methods="POST">
<inSequence>
<enrich>
<source clone="true" type="body"/>
<target property="inputBody" type="property"/>
</enrich>
<payloadFactory media-type="json">
<format>
{
"data": [
{
"eno": "100",
"sal": 2000
},
{
"eno": "101",
"sal": 2300
},
{
"eno": "102",
"sal": 1800
},
{
"eno": "104",
"sal": 2500
}
]
}
</format>
<args/>
</payloadFactory>
<foreach expression="json-eval($.data)" id="foreach_1">
<sequence>
<property expression="json-eval($.eno)" name="eno" scope="default" type="STRING"/>
<property expression="json-eval($.sal)" name="sal" scope="default" type="STRING"/>
<enrich>
<source clone="true" property="inputBody" type="property"/>
<target type="body"/>
</enrich>
<enrich>
<source clone="true" property="sal" type="property"/>
<target xpath="//data[eno=$ctx:eno]/sal"/>
</enrich>
<enrich>
<source clone="true" type="body"/>
<target property="inputBody" type="property"/>
</enrich>
</sequence>
</foreach>
<enrich>
<source clone="true" property="inputBody" type="property"/>
<target type="body"/>
</enrich>
<property name="messageType" scope="axis2" type="STRING" value="application/json"/>
<respond/>
</inSequence>
<outSequence/>
<faultSequence/>
</resource>
</api>