Parent and Child Tasks

Tasks can be organized in a hierarchy. When a task has one or more tasks beneath it, they are referred to as parents. The tasks underneath are called parents.

Working with Parent Tasks and Children

The Task class exposes classes that helps you determine:

• Parent: determines that a task is a parent task. Accepts and returns a Task object.
• Children: determines that a task is a child task. Accepts and returns an array list of Task objects.

Parent and Child Tasks in Microsoft Project

To declare a task as a parent or a child task in Microsoft Project:

1. In the Task Entry form, select a task and click it.
2. Select Outdent to turn a task into a parent, or,
3. Select Indent to turn a task into a child.

Parent tasks and children in Microsoft Project

Getting Parent and Child Tasks

The following examples show viewing parent and child tasks in a project using Aspose.Tasks.

// For complete examples and data files, please go to https://github.com/aspose-tasks/Aspose.Tasks-for-Java
// The path to the documents directory.
String dataDir = Utils.getDataDir(ParentAndChildTasks.class);

Project prj = new Project(dataDir + "ParentAndChildTask.mpp");

// Create a ChildTasksCollector instance
ChildTasksCollector collector = new ChildTasksCollector();

// Use TaskUtils to get all children tasks in RootTask
TaskUtils.apply(prj.getRootTask(), collector, 0);

List tasks = collector.getTasks();
int iSize = tasks.size();
// Parse through all the collected tasks
for (int i = 0; i < iSize; i++) {
    Task tsk = (Task) tasks.get(i);
    System.out.println("Task Name = " + tsk.get(Tsk.NAME));
}

Setting Child Tasks

// For complete examples and data files, please go to https://github.com/aspose-tasks/Aspose.Tasks-for-Java
// The path to the documents directory.
String dataDir = Utils.getDataDir(ParentAndChildTasks.class);

Project proj = new Project(dataDir + "Blank2010.mpp");
proj.set(Prj.NEW_TASKS_ARE_MANUAL, new NullableBool(false));
double oneDay = 8d * 60d * 60d * 10000000d;
java.util.Calendar cal = java.util.Calendar.getInstance();
cal.set(2014, 9, 13, 8, 0, 0);
Date startDate = cal.getTime();
proj.set(Prj.START_DATE, startDate);

Task task1 = proj.getRootTask().getChildren().add("Task 1");
cal.set(2014, 9, 13, 8, 0, 0);
task1.set(Tsk.START, cal.getTime());
task1.set(Tsk.DURATION, proj.getDuration(29, TimeUnitType.Day));
Task task2 = proj.getRootTask().getChildren().add("Task 2");

// add child tasks to task 2
Task task3 = task2.getChildren().add("Task 3");
Task task4 = task2.getChildren().add("Task 4");

cal.set(2014, 9, 15, 8, 0, 0);
task3.set(Tsk.START, cal.getTime());
task3.set(Tsk.DURATION, proj.getDuration(3, TimeUnitType.Day));
task3.set(Tsk.CONSTRAINT_TYPE, ConstraintType.StartNoEarlierThan);
task3.set(Tsk.CONSTRAINT_DATE, task3.get(Tsk.START));

cal.set(2014, 9, 17, 8, 0, 0);
task4.set(Tsk.START, cal.getTime());
task4.set(Tsk.DURATION, proj.getDuration(3, TimeUnitType.Day));
task4.set(Tsk.CONSTRAINT_TYPE, ConstraintType.StartNoEarlierThan);
task4.set(Tsk.CONSTRAINT_DATE, task3.get(Tsk.START));

task3.set(Tsk.PERCENT_COMPLETE, 50);
task4.set(Tsk.PERCENT_COMPLETE, 70);

proj.save(dataDir + "ProjectJava.mpp", SaveFileFormat.MPP);