Building A Simple Task

Writing and testing a simple task

Tasks prompt users to complete activities on a programmatic schedule. This guide will explain how to write a task which prompts CHW users to complete an assessment app form for new patients within 7 days of registration.

  • Creating a straight-forward task
  • Running and testing that task


Implementation Steps

Create a tasks.js file (this may have already been created by the initialise-project-layout command).

1. Define a Simple Task

The appearance, behaviour, and schedule of tasks are all controlled through the JavaScript in the tasks.js file. Let’s start in that file with a simple first task:

module.exports = [{
  name: 'assessment-after-registration',
  title: 'First Assessment',
  icon: 'icon-healthcare',
  appliesTo: 'contacts',
  appliesToType: ['patient'],
  appliesIf: c => user.parent && user.parent.contact_type === 'chw_area' && ! && !,
  actions: [{ form: 'assessment' }],
  events: [{
    start: 7,
    days: 7,
    end: 0,

What is this code doing?

The tasks.js file follows the JavaScript ES6 Module syntax and exports an array of objects matching the task.js schema*. In the code above, the tasks.js file is exporting one task object with the following:

  • name - This is used exclusively in the task’s backend data. The name isn’t controlling any element of the tasks’s behaviour, appearance, or schedule.
  • title - This is controlling the “Task title” as defined in the anatomy of a task.
  • icon - This references a resource to be used as the task’s icon. Refer to anatomy of a task.
  • appliesTo - We use contacts because we want one task per contact. For more details, read Understanding the data available in tasks and targets.
  • appliesToType - The task should only show for contacts with contact_type equal to patient. This appliesToType is a short-hand equivalent to appliesIf: c => === 'patient'.
  • appliesIf - A predicate which gates the creation of the task’s event schedule. For more details, read Understanding the data available in tasks and targets.
    • user.parent.contact_type - The user is a CHW iff their parent is of type chw_area. The user object is hydrated.
    • ! - The contact must be alive
    • ! - The contact must be unmuted
  • actions - Actions control what happens when the user “selects” the task (clicks on it or touches it). We want to have the single option of completing the assessment form.
  • events - This controls the task’s schedule. We want a single event because this is a one-time follow-up.
  • events[0].days - The task event is due 7 days after the contact’s creation date.
  • events[0].start - The task event should appear 7 days before the due date, or immediately when the contact is created.
  • events[0].end - The task event should disappear the day after the due date.

2. Uploading the Task

To run the tasks.js code, you’ll need to load the code into your running CHT application.

cht --url=https://<username>:<password>@localhost

or for a faster experience, compile and upload only the relevant changes:

cht --url=https://<username>:<password>@localhost compile-app-settings upload-app-settings

3. Testing the Task

Tasks are only available to offline users. To view and test this simple task, you’ll need to login as an offline user like the CHW-level user created in the Contact and User Management - Part 1 Tutorial. Once logged in, sync to make sure you have the latest configuration. You may be prompted to reload the application.

Create a new contact in the hierarchy and navigate to the Tasks tab. You should see the new assessment-after-registration task!

Next, test a few of the expected behaviours for the task:

  • Confirm that clicking on the task causes the assessment app form to load.
  • Confirm that completing the assessment app form causes the task to disappear.
  • Move your system clock forward 7 days and reload the tasks tab. You should see that the task is now “Due Today”.
  • Move your system clock forward 8 days and reload the tasks tab. The task should disappear since the 7 day window has expired.
  • Login as a supervisor user. You should not be able to see the task.
  • The task should not appear only for patients - not for places or CHWs.
  • If you mute a contact or report the contact dead, the task should disappear.

Frequently Asked Questions

CHT Applications > Features > Tasks

Ensuring that the right actions are taken for the right people at the right time

CHT Applications > Reference > tasks.js

Tasks: Definition of tasks shown to app users

CHT Applications > Concepts > Workflows

Building connections between people, actions, and data systems

Design System > Best Practices : Anatomy of a Task

This document covers the configuration best practices of forms, tasks, targets, and contact profiles when building your own community health app.

Last modified 25.04.2022: Fix broken image and link (fab814a2)