How to pass different data value to Alfresco activiti multi instance subprocess

Question

I have created a multi instance subprocess and the number of subprocesses is created dynamically using Multi-Instance's loopCardinality element but my problem is that I am not able to pass different-different data value to each subprocess.

Image here:

This is my problem scenario as shown in the above image. I want to divide subprocess based on loopCardinality value like:

int getSubProcessDataValue(int fileCount,int  loopCardinality){
    if(fileCount < 1 && loopCardinality < 1)
      return 0
    int result=fileCount/loopCardinality;
    return result;
}

Suppose fileCount=7 and loopCardinality=2 then the above function will return 3 for the first subprocess. It means I have to pass 3 file names to the first subprocess.

int getLastSubProcessDataValue(int fileCount,int  loopCardinality){
    if(fileCount < 1 && loopCardinality < 1)
       return 0
    int result=fileCount/loopCardinality;
    int rem=fileCount%loopCardinality;
    return result+rem;
}

Suppose fileCount=7 and loopCardinality=2 then the above function will return 4 for the last subprocess. It means I have to pass 4 file names to the last subprocess.

Anyone have an idea how to implement it? Please help me.

Answer 1

I have done it using TaskListener as shown below code:

package com.knovel.workflow.scripts;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.activiti.engine.delegate.DelegateTask;
import org.activiti.engine.delegate.TaskListener;

public class FileSplittingTaskListener implements TaskListener{

private static final long serialVersionUID = 3972525330472103945L;

@Override
public void notify(DelegateTask task) {
    System.out.println("#####FileSplittingTaskListener######");

    task.setVariable("bpm_assignee", task.getVariable("bpm_assignee"));
    task.setVariable("bpm_comment", task.getVariable("bpm_comment"));
    task.setVariable("bpm_dueDate", task.getDueDate());
    task.setVariable("bpm_priority", task.getPriority());

    String strFileSplitter=(String)task.getVariable("wf_fileSplitter");
    System.out.println("#############FileSplitter >>"+strFileSplitter);
    Integer fileSplitter=Integer.parseInt(strFileSplitter);
    System.out.println("#############FileSplitter >>"+fileSplitter);
    //task.setVariable("wf_taskCounter", fileSplitter);

    String workFlowFileName=(String) 
    task.getVariable("wf_workFlowFileName");
    String[] files=workFlowFileName.split("-");
    System.out.println("#######Files Length:"+files.length);
    List<String[]> filesList = splitArray(files, fileSplitter);

    List<String> fileList=new ArrayList<>();
    for (String[] lists : filesList) {
        String fileName="";
        int srNo=0;
        int count=1;
        for (String string : lists) {
            System.out.println("File>>"+string);
            if(count == lists.length){
                fileName=fileName+ ++srNo +"-"+string;
            }else{
                fileName=fileName+ ++srNo +"-"+string+",";
            }
            count++;
        }
        fileList.add(fileName);
        srNo=0;
     }
     System.out.println("FileList>>"+fileList);
     System.out.println("#############FileList >>"+fileList);
     task.setVariable("filesList", fileList);

    }

    public static <T extends Object> List<T[]> splitArray(T[] array, int 
    max){
    int x = array.length / max;
    int r = (array.length % max); // remainder

    int lower = 0;
    int upper = 0;
    List<T[]> list = new ArrayList<T[]>();
    int i=0;

    for(i=0; i<x; i++){
       upper += max;
       list.add(Arrays.copyOfRange(array, lower, upper));
       lower = upper;
     }

     if(r > 0){
       list.add(Arrays.copyOfRange(array, lower, (lower + r)));
     }

      return list;
    }
  }

And I have updated multiInstanceLoopCharacteristics element properties as shown below:

<multiInstanceLoopCharacteristics 
    isSequential="false" 
    activiti:collection="filesList" 
    activiti:elementVariable="wf_workFlowFileName">
</multiInstanceLoopCharacteristics>

Thank you so much for your valuable supports!!!

Answer 2

This is actually one of the coolest features of the Activiti engine in my opinion. You do this by using the collection option rather than setting the cardinality. The collection and elementValue options as shown below:

Here the number of instances will be determined by the size of the collection and the input variables "elementValue" will be the list element.

Using this approach you can pass different data into each instance of the multi instance loop.

Hope this helps, Greg