Manatee v2.0

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Tasks ​

The Tasks module can be used to paralellize parts of a flow. This is useful for e.g. doing concurrent http requests or running background tasks. It is not intended for use with field-operations i.e. interacting with a host applications UI since this interaction cannot be parallelized. Furthermore you should not display dialogs in parallelized tasks as they can block the calling flow.

Run ​

Use the run method to start a new task.

Parameters ​

  • fun a function to run in parallel

Returns ​

Example ​

Run some tasks and wait for the result.

javascript
var t = Task.run(
  function() { 
    var i = 0;
    while (i<1000) {
      i = i + 1;
    }
    return i;
  });

// Wait for t to complete or 1000ms to elapse
if (t.wait(1000)) {
  // Access the result
  if (t.done && !t.failed) {
    Debug.showDialog("It completed with result="+t.result);
  } else if (t.failed) {
    // only access t.error if t.failed == true
    Debug.showDialog("Took too long or errored? "+t.error !== null);
  }
} else {
  // 1 sec elapsed without the task completing
}

Run a task and execute a function when the task is done.

javascript
Task.run(...).then(function(result){ 
  // do something with the result of the task
});

Wait for all tasks to complete ​

This is used to wait until all the tasks given as arguments complete or given milliseconds elapse.

Parameters ​

  • tasks - an [array of tasks or javascript functions] to run asynchronously (and then wait for)
  • timeout [int] denoting the max number of milliseconds to wait for the tasks to complete

Returns ​

A [bool] indicating wether or not all tasks completed.

Example ​

javascript
var t = Task.run(function() { ... });
var tasks = [Task.run(function() { ... }), function() { ... }, t];

// Wait for tasks to complete or 1000ms to elapse
if (Task.waitAll(tasks, 1000)) {
  for (var i=0; i<tasks.length; i++) {
    Debug.showDialog("Task "+i+" resulted in "+tasks[i].result);
  }
  Debug.showDialog("It completed!");
} else {
  Debug.showDialog("Took too long");
}

Wait for any tasks to complete ​

This is used to wait until one of the tasks given as arguments completes or given milliseconds elapse.

Parameters ​

  • tasks - an [array of tasks or javascript functions] to run asynchronously (and then wait for one of)
  • timeout [int] denoting the max number of milliseconds to wait for any of the task to complete

Returns ​

An [int] denoting the index of the first task to complete or -1 if no tasks complete within given deadline.

Example ​

javascript
var t = Task.run(function() { ... });
var tasks = [Task.run(function() { ... }), function() { ... }, t];

// Wait for tasks to complete or 1000ms to elapse
var idx = Task.waitAny(tasks, 1000);
if(idx > 0) {
  Debug.showDialog("We have a winner: "+idx);
} else {
  Debug.showDialog("Took too long. Everybody lost.");
}

JavaScript Task ​

A javascript representation of a .NET task. It has 2 methods; wait(milliseconds) which can be used to wait for the task to complete or the given milliseconds to elapse, whichever comes first and then(func) which can be used to run a function when the task completes.

For an example see the Run method on the Task module.