Using CSOM to update multiple tasks with only 1 project publish - ms-project

Question

I have the following code that updates certain task fields. The problem with this code is that I have to publish an entire project after updating each task one-by-one. So for example, if I had 500 tasks to update, the project would have to be published 500 times. As you can see, this is completely overkill, slow and unnecessary.
using (ProjectContext projectContext = GetClientContext(psCred))
{
projectContext.Load(projectContext.Projects);
projectContext.ExecuteQuery();
foreach (var project in projectContext.Projects)
{
var draftProject = project.CheckOut();
projectContext.Load(draftProject.Tasks);
projectContext.ExecuteQuery();
projectContext.Load(draftProject.Task);
projectContext.ExecuteQuery();
foreach (var task in draftProject.Tasks)
{
task["FIELD"] = "VALUE";
var job = draftProject.Update();
projectContext.WaitForQueue(job, int.MaxValue);
job = draftProject.Publish(true);
projectContext.WaitForQueue(job, int.MaxValue);
}
}
}
I hope there is a way to update update all of the project tasks at once with only one publish at the end just like how Microsoft Project desktop application does it.

Answer 1

For what it's worth, I was able to create a bunch of tasks and then use this code to update a custom field on all of the new/existing tasks with a single publish:
DraftProject projCheckedOut = proj2Edit.CheckOut();
_projContext.Load(projCheckedOut.Tasks, ts =>
ts.Include(
t => t.Id,
t => t.Name,
t => t.CustomFields,
t => t.OutlineLevel,
t => t.IsSummary));
_projContext.ExecuteQuery();
// Lookup custom field internal name from our StringDictionary
string intNamePref = _customFields["Custom Field1"];
var tasks = projCheckedOut.Tasks;
foreach (var t in tasks)
{
t[intNamePref] = 2;
}
projCheckedOut.Publish(true);
_projContext.ExecuteQuery();
Tip, to get the .Include lambda to work, I had to add this using:
using Microsoft.SharePoint.Client;