Using open source for free tasks

Why all the effort?

Online task lists are dissappearing left and right (for example Astrid and Wunderlist). You want your tasks under your control which means:

You have an open file format storing the tasks.
You can synchronize or serve the tasks with open source tools.

I started with todo.txt to store my tasks. This works fine, but a format like todo.txt has one big disadvantage: it doesn’t have a concept of task identity so any syncing solution is flaky.

After some searching I found https://taskwarrior.org/[Taskwarrior] which not only provides a flexible plain text task storage solution, but it also provide a very robust syncing solution with taskd.

The set-up

I use my own taskd server on a Archlinux based VPS. For now I try to stay away from user defined attributes (UDAs) as much as possible to keep the setup simple.

Accessing the tasks

Linux CLI

import os
import sequtils
import strutils

# escape arguments for bash
var cmdArgs =  commandLineParams()
               .map(proc (s: string): string = r"$'" & s.replace(r"'",r"\'") & "'")
               .join(" ")
var shellCmd = r"bash -c ""task "  & cmdArgs & "\""
quit(os.execShellCmd(shellCmd))

Web interface

As a web interface I used inthe.am but even though the code is open source, that site is not under my control and thus could disappear at any time.

Instead I now use taskwarrior-web. This is intended for localhost usage and as a result has no authentication. To make it safe to open this from my own website, I have put it behind a nginx reverse proxy with basic HTTP authentication.

server {
    listen 443 ssl;
    ssl_certificate /etc/letsencrypt/live/mpcjanssen.nl/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/mpcjanssen.nl/privkey.pem;
    server_name tasks.mpcjanssen.nl;
    access_log /var/log/nginx/service.tasks.mpcjanssen.nl.access.log;
    error_log /var/log/nginx/service.tasks.mpcjanssen.nl.error.log;
    location / {
        proxy_pass http://127.0.0.1:5678;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Proto $scheme;
        auth_basic "Restricted Content";
        auth_basic_user_file /etc/nginx/.htpasswd;
    }
}

I start the ruby gem itself using the following user systemd script at ~/.config/systemd/user/taskweb@.service:

[Unit]
Description=Taskwarrior web

[Service]
Type=simple
SuccessExitStatus=0 1

ExecStart=/home/mpcjanssen/.gem/ruby/2.4.0/bin/task-web -o 127.0.0.1 -d -F

Android

Android has two good clients already Taskwarrior for Android and TaskwarriorC2. However they are missing quite some functionallity I have implemented in my todo.txt app Simpletask. So I am planning to support Taskwarrior in Simpletask.

Capturing tasks

For capturing tasks, I either use the CLI tools, or I use the org-protocl browser plugins with a custom org-protocl handler script in Tcl:

puts "Handling org-protocol call"

proc invalidcall {} {
  puts stderr "Invalid org-protocol call $::argv"
  exit 1
}

proc expandPercent {data} {
    set pos 0
    while { -1 != [set pos [string first "%" $data $pos]]} {
        set hexNumber "0x[string range $data $pos+1 $pos+2]"
        if { 4 != [string length $hexNumber] || ! [string is integer $hexNumber] } {
            # No two hex character - eventual error treatment here
            # at the moment just leave the percent character
        } else {
            set data [string range $data 0 $pos-1][format %c $hexNumber][string range $data $pos+3 end]
        }
        incr pos
    }
    return $data
}

proc handlecapture {type url title {text {}}} {
  puts "URL: $url"
  set url [expandPercent $url]
  set title [string trim [expandPercent $title]]
  set text [string trim [expandPercent $text]]

  puts "URL: $url"
  puts "title: $title"
  puts "text: $text"
  # console show
  # vwait forever
  captureAddTaskwarriorWindows $url $title $text
  exit 0

}

proc captureAddTaskwarriorWindows {url title text} {
    if {[catch {exec task add $title} result]} {
    puts $result
    gets stdin
    } else {
      set taskId [string range [lindex [split $result] end] 0 end-1]
      exec task $taskId annotate Captured url: $url
    }
}

proc captureAppendTodoTxt {url title text} {
  set f [open "~/Dropbox/todo/todo.txt" a]
  set timestamp [clock format [clock seconds] -format %Y-%m-%d]
  puts $f "$timestamp $title $url +orgcapture"
  close $f
}

if {$argc != 1} {
  invalidcall
}

lassign $argv protocall

if {!([string first org-protocol:// $protocall] == 0)} {
  invalidcall
}

set prefixlength [string length org-protocol://]

set protocall [string range $protocall $prefixlength end]

puts $protocall

set arguments [lassign [split $protocall /] action]

switch -exact -- $action {
  capture: { handlecapture {*}$arguments } 
  default { 
    puts stderr "Unsupported action $action from $argv"
    exit 1
  }
}

To register the handler use:

REGEDIT4

[HKEY_CLASSES_ROOT\org-protocol]
@="URL:Org Protocol"
"URL Protocol"=""
[HKEY_CLASSES_ROOT\org-protocol\shell]
[HKEY_CLASSES_ROOT\org-protocol\shell\open]
[HKEY_CLASSES_ROOT\org-protocol\shell\open\command]
@="\"C:\\Bin\\org-protocol-handler.exe\" \"%1\""