Scheme is a clone of Asana, the popular project management app. Scheme was made with Ruby on Rails and React.js.
Scheme users can prioritize tasks by dragging and dropping them into the desired order.
Task order is maintained in a linked-list data structure. Each task knows the IDs of its next
and previous
tasks, and every project knows its last_task_id
. To assemble the tasks in the correct order and avoid n+1 queries, Scheme retrieves an unordered group of tasks within a project, hashes them by ID, and then references the next_task_id
s to create an array of tasks in the user’s designated order.
var sortTasks = function (tasksObj, lastTaskId) {
// start by inserting last task into ordered array
var taskArr = [tasksObj[lastTaskId]];
// then insert the previous task, until !previous_task_id
while (taskArr[0].previous_task_id) {
taskArr.unshift(tasksObj[taskArr[0].previous_task_id]);
}
return taskArr;
};
Thanks to the linked-list structure, re-ordering tasks within a project is an O(1) time operation, and requires updating only 3-5 task records, no matter how many tasks a project includes.
- Add / delete / complete tasks
- Assign tasks and set deadlines
- Create projects to organize tasks
- Invite other users to join your "team"
- Drag-n-drop ordering of tasks
- Drag-n-drop uploading of profile pictures
- Comment on tasks
- See new tasks and comments from other users in realtime
- React.js
- Flux
- Ruby on Rails
- JSON API
- PostgreSQL
- Pusher
- Sendgrid
- Heroku