Returning a Custom Result with Automation

As automatic marshalling is not implemented into Automation server and client, only Document(s) and Blob(s) can be manipulated. Therefore, the way to return a custom type is to encapsulate the value in a Blob.

Below is an example, based on the results returned by the method QueryAndFetch.

• Operation code

  package org.nuxeo.support;
  
  import java.io.ByteArrayInputStream;
  import java.io.Serializable;
  import java.util.Iterator;
  import java.util.Map;
  
  import net.sf.json.JSONArray;
  import net.sf.json.JSONObject;
  
  import org.nuxeo.ecm.automation.core.Constants;
  import org.nuxeo.ecm.automation.core.annotations.Context;
  import org.nuxeo.ecm.automation.core.annotations.Operation;
  import org.nuxeo.ecm.automation.core.annotations.OperationMethod;
  import org.nuxeo.ecm.automation.core.annotations.Param;
  import org.nuxeo.ecm.core.api.Blob;
  import org.nuxeo.ecm.core.api.CoreSession;
  import org.nuxeo.ecm.core.api.IterableQueryResult;
  import org.nuxeo.ecm.core.api.impl.blob.StringBlob;
  import org.nuxeo.ecm.core.query.sql.NXQL;
  
  @Operation(id = QueryAndFetch.ID, category = Constants.CAT_FETCH, label = "QueryAndFetch", description = "Sample to show how to return a blob for any result type.")
  public class QueryAndFetch {
  
      public static final String ID = "Test.QueryAndFetch";
  
      @Context
      protected CoreSession session;
  
      @Param(name = "query")
      protected String query;
  
      protected String lang = NXQL.NXQL;
  
      @OperationMethod
      public Blob run() throws Exception {
          IterableQueryResult result = session.queryAndFetch(query, lang);
          Iterator<Map<String, Serializable>> it = result.iterator();
  
          JSONArray array = new JSONArray();
          while (it.hasNext()) {
              Map<String, Serializable> item = it.next();
              JSONObject object = new JSONObject();
              object.accumulateAll(item);
              array.add(object);
          }
  
          return new StringBlob(array.toString(), "application/json");
  
      }
  
  }
  
  

• Registering this operation

  <?xml version="1.0"?>
  <component name="org.nuxeo.support.operations">
  
    <extension target="org.nuxeo.ecm.core.operation.OperationServiceComponent"
      point="operations">
      <operation class="org.nuxeo.support.QueryAndFetch" />
    </extension>
  </component>
  

• Sample code to use the result from the operation

  HttpAutomationClient client = new HttpAutomationClient("http://localhost:8080/nuxeo/site/automation");
  
  Session session = client.getSession(ADMINISTRATOR, ADMINISTRATOR);
  Blob response = (Blob) session.newRequest(QueryAndFetch.ID).set("query", "select ecm:uuid, dc:title, common:icon from Document").execute();
  String json = FileUtils.read(response.getStream());
  JSONArray array = JSONArray.fromObject(json);
  System.out.println("Objects received : " + array.size());