Mule Dataweave Object to Array Error

Question

I am trying to extract category-id when primary = true by grouping of product-id

%input payload application/xml
%output application/java
---
using (c=payload.catalog.*category-assignment default [])

((c default []) filter ($.@mode != "delete")  groupBy $.@product-id map ({

    (($ default []) filter ($.primary == 'true') map ({
            field3:$.@category-id
        }) when $.primary != null otherwise field3:"" ),

        cat-id: $.@category-id joinBy "||" ,
        primary-flag:$.primary

//    (($ default []) filter ($.primary matches /true/) map ({
//            //ur code here when equals to shipping charges
//            field3:$.@category-id
//        }) when $.primary != null otherwise [] ) ,

}))

I tried with multiple combination and filters. Filter generally works with xml attributes, but here giving exception

cast to com.mulesoft.weave.model.structure.ObjectSeq (java.lang.ClassCastException). Message payload is of type: ReceiverFileInputStream

Sample input -

<?xml version="1.0" encoding="UTF-8"?>
<catalog xmlns="http://www.example.com/xml/impex/catalog/2006-10-31">
<category-assignment product-id="D711069" category-id="4160">
    <primary>true</primary>
  </category-assignment>
<category-assignment product-id="D711069" category-id="DANIEL_4160"/>
</catalog>

Any suggestions here?

I tried another set of transformation just for demo, not working -

%input payload application/xml
%output application/xml
---

Test:{((payload.catalog.*category-assignment default []) groupBy $.@product-id pluck {

        product-id:$$,
        cat-id: $.@category-id joinBy "||" ,
        primary-flag:$[0].primary,

        field3:$.@category-id[?($.primary == "true")]

    })}

Answer 1

Try out this expression. Can you elaborate your expected output?

using (c=payload.catalog.*category-assignment default [])
(c[?(($.primary == "true") and ($.@mode != "delete"))] groupBy $.@product-id map {
  field3:$.@category-id,
  primary-flag:$.primary
})

Updated dataweave as per your comments:

%dw 1.0
%output application/csv
---

payload.catalog.*category-assignment[?(($.primary == "true") and ($.@mode != "delete"))] groupBy $.@product-id map {
productid:$.@product-id[0],
categoryid: arrayToString($.@category-id, sizeOf $.@category-id)

Add global configuration element as shown below:

<configuration doc:name="Configuration">
    <expression-language>
        <global-functions>
def arrayToString(arrayObj,length){
String r=null;
    if(arrayObj==null){
        return "null";
    }else if(arrayObj==""){
        return "Empty";
    }else{
        for (String s:arrayObj) {
            if(r != null)
                r = r + '||' + s;
            else {
               r = s;
            }
        }
        return r;
    }
}
        </global-functions>
    </expression-language>
</configuration>

Answer 2

Try this expression, it will produce the CSV as per your stated requirement(s).

%dw 1.0
%output application/csv header=true
---
using (ca = payload.catalog.*category-assignment)
(
payload.catalog map (catVal, idx) -> ({
    ( 
        ca groupBy $.@product-id pluck {
            product-id:$$,
            cat-id: $.@category-id joinBy "||" 
            ,primary-flag:$.primary[0] default "false"
            ,(field3:$.@category-id[0]) when ($.primary[0] contains "true")
        }
    )
}) distinctBy $
)

it produces the output as:

product-id,cat-id,primary,field3
D711069,DANIEL_4160||4160||DANIEL_4160,true,DANIEL_4160

input used:

<?xml version="1.0" encoding="UTF-8"?>
<catalog>
<category-assignment product-id="D711069" category-id="DANIEL_4160"/>   
<category-assignment product-id="D711069" category-id="4160">
  <primary>true</primary>
</category-assignment>
<category-assignment product-id="D711069" category-id="DANIEL_4160"/>
</catalog>

HTH