Parse JSON Response Array using ForEach component in WSO2 ESB - wso2

Question

I have a requirement to parse JSON response which contain array of products(P1,P2,P3,etc.). Each product contains multiple information like name, type, cost, etc.
I need to read each product one by one and append additional data got from the another service into an new JSON output. I am thinking of using ForEach component of WSO2 ESB to iterate each product one by one.
Problem is that ForEach component uses ForEachExpression which expects XML expression in the configuration.
Please suggest on the method to parse array of JSON response one by one in WSO2 ESB.
/Abhishek

Answer 1

Can use both Iterate or ForEach mediator for iterating the JSON array, since both are content aware mediators and support JSON.
Which one to use depends upon the specific usecase as Iterate provides the capability to use call / callout / send mediators in the sequence whereas ForEach doesn´t allow it.
For the below given sample JSON request, the following iteration works and the JSON array and objects can be referred like the same.
{
"products":[
{
"product":{
"id":"1234",
"size":"20",
"quantity":"1",
"price":"990",
"type":"Electronics",
"store":{
"id":"001"
}
}
}
]
}
<iterate expression="//products" id="PRD_ITR">
<target>
<sequence>
<sequence key="Product_Enrich_Sequence_s"/>
<!-- For example, Switching sequence based on the product type -->
<switch source="//products/product/type">
<case regex="Computer">
<sequence key="Computer_Product_Enrich_Sequence_s"/>
</case>
<case regex="Mobile">
<sequence key="Mobile_Product_Enrich_Sequence_s"/>
</case>
<case regex="Grocery">
<sequence key="GR_Product_Enrich_Sequence_s"/>
</case>
<default>
<!-- default stuff --!>
</default>
</switch>
</sequence>
</target>
</iterate>
FYR
https://docs.wso2.com/display/ESB490/Iterate+Mediator
https://docs.wso2.com/display/ESB490/ForEach+Mediator
Note: tested in WSO2 ESB 4.9.0