Load all task dates#

Get the start, end and duration of every scheduled task from one solve, for example to fill your UI when a project first opens.

By default, updates in a ScheduleResult is sparse: it lists only the tasks that moved. Set SolveOptions.includeUnchanged and the same solve also reports the tasks that didn't move. You don't need a separate call.

Steps#

1. Build the solve options with includeUnchanged set to true:

   Copy

   var options = new SolveOptions().withIncludeUnchanged(true);
   

2. Pass the options to the solve that loads the data. Use Project#solve with the data for a long-lived project, or Engine.schedule for a one-shot job.

3. Read every entry of result.updates. Each Mutation has startDate, endDate and duration set.

The full example below schedules three tasks. review doesn't move, but it's still reported:

import java.util.List;
import org.dhtmlx.plen.*;

public class LoadAllTaskDates {
  static TaskData task(String id, Moment start, double duration) {
    return new TaskData(Id.str(id)).withStartDate(start).withDuration(duration);
  }

  public static void main(String[] args) throws Exception {
    var jan1 = Moment.fromYmdHm(2026, 1, 1, 0, 0);
    var jan5 = Moment.fromYmdHm(2026, 1, 5, 0, 0);

    var data = new ProjectData()
        .withTasks(List.of(
            task("design", jan1, 2.0),
            task("build", jan1, 1.0),
            task("review", jan5, 1.0)))
        .withLinks(List.of(
            new LinkData()
                .withId(Id.str("design-build"))
                .withSource(Id.str("design"))
                .withTarget(Id.str("build"))
                .withLinkType(LinkType.FS)));
    // 24/7 time keeps the example dates easy to check.
    data.config.useCalendars = false;

    var options = new SolveOptions().withIncludeUnchanged(true);

    var project = new Project();
    var result = project.solve(data, options);

    for (var m : result.updates) {
      System.out.println(m.id + " " + m.startDate + ".." + m.endDate + " " + m.duration);
    }
  }
}

Get the full list from an already solved project#

To reload every date later, call solve(null, ...) with the same options. On a solved project with no pending edits, the call doesn't replan or change the accepted state, and baselineId stays the same:

var allDates = project.solve(null, options);

Switch back to sparse results for the edits that follow. new SolveOptions() returns only what changed:

var next = project.solve(null, new SolveOptions());

The result cache uses the whole SolveOptions as its key, compared by value. An includeUnchanged call never gets a cached sparse result, and a sparse call never gets a cached full one.

What is and isn't reported#

• The result includes every scheduled task: leaf tasks, summaries and milestones. Check Mutation.kind (MutationKind.TASK, SUMMARY, MILESTONE) to tell them apart.
• Tasks with unscheduled = true are never reported.
• levelingDelay and pauses are always null, because a solve doesn't change them.
• baselineId follows real changes only. Asking for unchanged tasks doesn't create a new baseline.
• With subtree, the result holds every task in the subtree, including the subtree tasks' ancestors. Tasks outside the subtree appear only when a sparse subtree solve would report them too, because they changed or were edited.
• On a project with a dependency cycle, nothing is scheduled. The result still lists every scheduled task, in model order, with its dates and duration as stored. subtree is ignored, and no entry has a reason, even with reasons = true.
• Project#preview and Project#level always return sparse updates.

Result#

The example prints one line per task, including review, which didn't move (the lines may come in a different order):

design 2026-01-01 00:00..2026-01-03 00:00 2.0
build 2026-01-03 00:00..2026-01-04 00:00 1.0
review 2026-01-05 00:00..2026-01-06 00:00 1.0

Without includeUnchanged, the same solve reports only build.

See Reading results for how to write the dates back into your model.