of3-add-new-task-to-selected-proj.js

//Also see question and answer at https://discourse.omnigroup.com/t/add-a-new-task-and-set-the-project-it-belongs-to-via-javascript-of3/44111

var app = Application('OmniFocus');
app.includeStandardAdditions = true;
var doc = app.defaultDocument;
var content = doc.documentWindows.at(0).content;
var selectedTree = content.selectedTrees();
var selectedLen = selectedTree.length

var proj = null
if (selectedLen == 0) {
  app.displayDialog("Nothing selected in Omnifocus");
} else if (selectedLen > 1) {
  app.displayDialog("More than one object selected in Omnifocus");
} else {
  try{
    var proj = selectedTree[0]
    proj.value().status()
  }catch(e) {
    proj = null
    app.displayDialog("Selected item is not a Project");
  }
}
if (proj !== null) {
  app.displayDialog("Project Selected"
    + "\nid: [" + proj.id() + "]\nname: [" + proj.name()
    + "]\nstatus: " + proj.value().status() + "\nnumberOfAvailableTasks: [" + proj.value().numberOfAvailableTasks() + "]");

  var newTask = app.Task({ 
    name: 'sample task',
    note: 'a note',
  });
  //Bingo... this is how you push a task into a project.
  proj.value().tasks.push(newTask);
}