How to Create a Good Parent-Child Workflow

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Well, everyone, are your parent-child relationships going well?
Likewise, concerning the Workflow, there are people who want to build a good parent-child relationship on the Workflow.
I have occasionally heard of business processes like the following:

It seems hard to do, but it’s possible if you use Questetra.
I will explain how, based on a specific case.

The use case

The business scenario is…

Implementation in Questetra

Outline

The outline of the implementation is as follows.

There are the following conditions to satisfy:

Definition of Workflow App

Launching of child App

Launching of the child App is performed by accessing a Message Start Event (HTTP) on the child flow App. At that time, the related contract info which has been entered in a Table-type Data Item in the parent App is passed over.

The starting up part is performed by the Script Task.

＜Interface of Message Start Event (HTTP) on child flow＞

＜Contents of Script Task “Start up” on child flow＞

var parentNumber = engine.findDataByNumber("1");
var table = engine.findDataByNumber("0");
var childName = "";
var childNumber = "";
var uri = "https://****************.questetra.net/System/Event/MessageStart/22/0/start";
var keyValue = "*******************";

for (var i=0 ; i < table.size(); i++){
  childName = table.get(i,0);
  childNumber = table.get(i,1);
  try{
    var response = httpClient.begin()
      .queryParam("key",keyValue)
      .queryParam("data[0].input",parentNumber)
      .queryParam("data[1].input",childNumber)
      .queryParam("data[2].input",childName)
      .queryParam("data[4].input",processInstance.getProcessInstanceId())
      .get( uri );
    engine.log("StatusCode:" + response.getStatusCode() + ":" + response.getResponseAsString() + "\n");
    if( response.getStatusCode() != 200 ){
      engine.log("Exception:send error:" + response.getStatusCode() + "\n");
    }
  }catch(e){
    engine.log("exception:noSending\n");
  }
}

Confirmation on Child-flow completion

Since the Process ID of the parent flow is linked to the child flow, The Workflow API uses the Process ID to confirm whether or not all processes have been completed.
Specifically, it uses /API /OR/ProcessInstance/list and performs the retrieval at the Script Task.
The criteria necessary for the retrieval is as follows.

＜Criteria for retrieving related child flow＞

<process-instance-criteria>
  <process-model-info-id>●● App ID of child flow ●●</process-model-info-id>
  <states><state>STARTED</state></states>
  <data>
    <decimal>
      <data-definition-number>●● Data Item number in which Process ID of parent App is stored ●●</data-definition-number>
      <equals/>
      <value>●● Process ID of parent flow ●●</value>
    </decimal>
  </data>
</process-instance-criteria>

＜Contents of Script Task for retrieval in related child flow＞

var parentNumber = engine.findDataByNumber("1");
var uri = "https://*******************.questetra.net/API/OR/ProcessInstance/list";
var userName = "furukubo@questetra.com";
var appPass = "**************************";
var appId = "22";
var finished = false;
var selects = new java.util.ArrayList();

var criteria = "<process-instance-criteria><process-model-info-id>";
criteria += appId;
criteria += "</process-model-info-id>";
criteria += "<states><state>STARTED</state></states>";
criteria += "<data><decimal><data-definition-number>4</data-definition-number><equals/>"
criteria += "<value>" + processInstance.getProcessInstanceId() + "</value></decimal></data>";
criteria += "</process-instance-criteria>";

try{
  var response = httpClient.begin()
    .queryParam( "criteria", criteria )
    .basic(userName,appPass)
    .get( uri );
  engine.log(" uri:" + uri + "\n criteria:" + criteria + "\n");
  responseJson = response.getResponseAsString();
  engine.log("StatusCode:" + response.getStatusCode() + "\n");
  if( response.getStatusCode() == 200 ){
    var jsonObj = JSON.parse( responseJson );
    engine.log("count:" + jsonObj.count + "\n");
    if (jsonObj.count == 0){
      finished = true;
    }
  }else{
    engine.log("Exception:send error\n");
  }
}catch(e){
  engine.log("exception:noSending\n");
}
if (finished){
  selects.add("All child contract completed");
  engine.setDataByNumber("3",selects);
}

* For the Basic authentication for accessing /API /OR/ProcessInstance/list, specify a User who has Data Viewer authorization on the child flow App.
* The password for Basic Authentication is different from the normal login password. (You can check yours in Account Settings.)

Afterword

I believe that there are many cases where parent-child Workflows can be used.
Although most of these cases might be one on one, there may be cases like the use case in this article, which involve starting up an unspecified number of child flows. For example:

• Sub-projects under a system development project
• An event plan that consists of many small events

In these above cases, the progress of the child flow is possibly related with the progress of the parent flow.

I hope that the sample flow I introduced in this article may be helpful to you for business of this kind.

Please try it once by all means, and if you have any questions please do not hesitate to contact us.