How to implement $expand scenario with soap data source

[former_member201838]

$Expand is supported in soap data source when a web service has an operation which returns 2 structures and there has to be a primary key, foreign key relationship between them. There has to be provision to create a navigation property between these 2 entities in odata model

Steps from Design Time tool

1. Create an OData Service Implementation Project
2. Create an OData Model for 2 entities Header and Items.
   Define navigation from Header to Items as below. This model fetches collection of header and the items associated with that header. So the web service must have an operation which can return collection of header and collection of items. PROP1 is a primary key in ZKRAN_HDR entity set and PROP1 is a foreign key in ZKRAN_ITEM entity set. In the association defined PROP1 of header entity will be a principal key and PROP1 of item entity will be a dependent key.

   3. Right click on odatasvc and choose Select data source

   4. Select the HDR entitySet and choose the read CRUD operation. Select the data source as SOAP Service. Note: query operation can also be done

  5. Specify the wsdl file and choose the correct operation from the list of soap operations and click on finish.

   6. Right click on Query and select Define Custom Code

   7. Select the script type as either javascript or groovy script

  8. This being a read operation do a request mapping as below

  9. Do response mapping as below which maps only properties of header entity set since data source is added for header entity. The response obtained  from web service contains the items associated with the header based on PROP1. But the items are mapped using custom code

   10. In processResponseXML function the entire response from web service is fetched. This is parsed in order to get the list of hashmaps of items. Another list of hashmap must be created whose key will be Items entity set name and value will be previously created list of hashmap

function processResponseXML(message) {

  importPackage(java.util);

  importPackage(java.lang);

  var payload = message.getBody().toString();

  var tokens = payload.split("(?=<)|(?<=>)");

  var list = new ArrayList();

  var innerMap = new LinkedHashMap();

  var items = new ArrayList();

  var foundETItems = false;

  for (var i = 0; i < tokens.length; i++) {

   if (tokens[i].contains("<ET_ITEMS>")) {

    log.logErrors(LogMessage.TechnicalError, "Found ET_ITEMS");

    foundETItems = true;

    var itemMap = new LinkedHashMap();

    // Iterate each item

    for (var j = i+1; j < tokens.length; j++) {

     if(tokens[j].contains("</ET_ITEMS>")) {

      log.logErrors(LogMessage.TechnicalError, "Completed ET_ITEMS");

      break;

     }

     if(tokens[j].contains("<item>")) {

      continue;

     }

     if(tokens[j].contains("</item>")) {

      items.add(itemMap);

      itemMap = new LinkedHashMap();

      continue;

     }

     itemMap.put(tokens[j].substring(1,tokens[j].length()-1), tokens[j+1]);

     log.logErrors(LogMessage.TechnicalError, "For entry "+tokens[j].substring(1,tokens[j].length()-1)+" added value: "+tokens[j+1]);

     j = j + 2;

    }

   }

  }

  if(foundETItems) {

   innerMap.put("ZKRAN_ITEMSet", items);

   list.add(innerMap);

  }

  // Set the list of hashMaps to a header

  message.setHeader("MappingOutput", list);

  return message;

}

  11. In processResponseData message body will have data which is the output from mapping. Data from message header and message body are combined to a new list of hashmap.

function processResponseData(message) {

importPackage(java.util);

 importPackage(com.sap.gateway.ip.core.customdev.logging);

 

 // Get the data from the previously set header

 var data = message.getHeaders().get("MappingOutput"); 

 log.logErrors(LogMessage.TechnicalError, data);

 

 var body = message.getBody();

 var newData = null;

 var newList = new ArrayList();

for (var i = 0; i < data.size(); i++) {

  newData = new LinkedHashMap();

  var dyData = data.get(i);

  var mappedData = body.get(i);

  newData.putAll(mappedData);

  newData.putAll(dyData);

  newList.add(newData);

 }

 log.logErrors(LogMessage.TechnicalError, newList);

 message.setBody(newList);

 return message;

}

Note: the entity to be expanded is fetched in processResponseData function and the entities which are associated with the main entity are fetched from processResponseXML function.

The request payload looks like

<soapenv:Body>
<urn:ZKRAN_TEST_EXPAND>      
<IV_HDR_ID>AA</IV_HDR_ID>   
</urn:ZKRAN_TEST_EXPAND>

</soapenv:Body>

The response payload looks like

<n0:ZKRAN_TEST_EXPANDResponse xmlns:n0="urn:sap-com:document:sap:rfc:functions">

                <ES_HDR>

                                  <PROP1>AA</PROP1>

                                  <PROP2>HelloAA</PROP2>

                                  <PROP3>BlahAA</PROP3>

                  </ES_HDR>

                  <ET_ITEMS>

                                  <item>

                                                  <PROP1>AA</PROP1>

                                                  <ITPROP2>AA1</ITPROP2>

                                                  <ITPROP3>Good Day</ITPROP3>

                                  </item>

                                  <item>

                                                  <PROP1>AA</PROP1>

                                                  <ITPROP2>AA2</ITPROP2>

                                                  <ITPROP3>Hello</ITPROP3>

                                  </item>

                  </ET_ITEMS>

  </n0:ZKRAN_TEST_EXPANDResponse>

   12. Right Click on Project and select Generate and Deploy Integration Content. This will deploy the bundle.

  Now fire an OData Request is https://localhost:8083/gateway/odata/SAP/SOAP;v=1/ZKRAN_HDRSet('AA')?$expand=ZKRAN_ITEMSet on the browser and response will give collection of headers and collection of items associated with header AA.

Note: If the odata request is https://localhost:8083/gateway/odata/SAP/SOAP;v=1/Products(1)?$expand=Category,Suppliers

1. Create a list of hashmap of attributes of category.
2. Create a list of hashmap of attributes of Suppliers.
3. Create a list of hashmap with key as CategoryEntitySet name and value is output from 1 and another hashmap entry with key as SupplierEntitySet name and value is output from 2.
4. Create a list of hashmap of attributes of product and hashmap fetched from the list created in 3.

If Product has the below fields

Product_id	Product_Name
1	Pepsi
2	Amul Ice Cream

If Category has below fields

Category_Id	Product_id	Category_Description
10	1	Beverages
20	1	Desserts

If Supplier has below fields

Supplier_Id	Product_id	Supplier_Description
100	1	ABC
200	2	XYZ

$Expand output based on above mentioned steps look like

1. {Category_Id=10,Product_id=1,Category_Description=Beverages},
   { Category_Id=20,Product_id=1,Category_Description=Desserts}
2. {Supplier_Id=100,Product_id=1,Supplier_Description=ABC}
3. {CategorySet=[{Category_Id=10,Product_id=1,Category_Description=Beverages},
   { Category_Id=20,Product_id=1,Category_Description=Desserts }]},
   {SupplierSet=[{Supplier_Id=100,Product_id=1,Supplier_Description=ABC}]}
4. [{Product_id=1,Product_Name=Pepsi, CategorySet=[{Category_Id=10,Product_id=1,Category_Description=Beverages},
   { Category_Id=20,Product_id=1,Category_Description=Desserts }], SupplierSet=[{Supplier_Id=100,Product_id=1,Supplier_Description=ABC}]}]