Yanick Champoux
and 1 contributors

NAME

Taskwarrior::Kusarigama - plugin system for the Taskwarrior task manager

VERSION

version 0.3.1

SYNOPSIS

    $ task-kusarigama add GitCommit Command::Before Command::After

    $ task-kusarigama install

    # enjoy!

DESCRIPTION

This module provides a plugin-based way to run hooks and custom commands for the cli-based task manager Taskwarrior.

Configuring Taskwarrior to use Taskwarrior::Kusarigama

Setting up the hooks

Taskwarrior's main method of customization is via hooks that are executed when the command is run, when it exits, and when tasks are modified or added. (see https://taskwarrior.org/docs/hooks.html for the official documentation) Taskwarrior::Kusarigama leverages this hook system to allow the creation of custom behaviors and commands.

First, you need to install hook scripts that will invoke Taskwarrior::Kusarigama when task is running. You can do that by either using the helper task-kusarigama:

    $ task-kusarigama install

Or dropping manually hook scripts in the ~/.task/hooks directory. The scripts should look like

    #!/usr/bin/env perl

    # script '~/.task/hooks/on-launch-kusarigama.pl'

    use Taskwarrior::Kusarigama;

    Taskwarrior::Kusarigama->new( raw_args => \@ARGV )
        ->run_event( 'launch' ); # change with 'add', 'modify', 'exit' 
                                 # for the different scripts

Setting which plugins to use

Then you need to tell the system with plugins to use, either via task-kusarigama

    $ task-kusarigama add Command::After

or directly via the Taskwarrior config command

    $ task config  task-kusarigama.plugins  Command::After

Configure the plugins

The last step is to configure the different plugins. Read their documentation to do it manually or, again, use task-kusarigama.

    $ task-kusarigama install

Writing plugins

The inner workings of the plugin system are fairly simple.

The list of plugins we want to be active lives in the taskwarrior configuration under the key <kusarigama.plugins>. E.g.,

    kusarigama.plugins=Renew,Command::Before,Command::After,+FishCurrent

Plugin namess prefixed with a plus sign are left left alone (minus the '+'), while the other ones get Taskwarrior::Kusarigama::Plugin:: prefixed to them.

The Taskwarrior::Kusarigama system itself is invoked via the scripts put in ~/.task/hooks by task-kusarigama. The scripts detect in which stage they are called (launch, exit, add or modified), and execute all plugins that consume the associated role (e.g., Taskwarrior::Kusarigama::Hook::OnLaunch), in the order they have been configured.

For example, this plugin will runs on a four hook stages:

    package Taskwarrior::Kusarigama::Plugin::PrintStage;

    use 5.10.0;

    use strict;
    use warnings;

    use Moo;

    extends 'Taskwarrior::Kusarigama::Plugin';

    with 'Taskwarrior::Kusarigama::Hook::OnLaunch',
         'Taskwarrior::Kusarigama::Hook::OnAdd',
         'Taskwarrior::Kusarigama::Hook::OnModify',
         'Taskwarrior::Kusarigama::Hook::OnExit';

    sub on_launch { say "launch stage: ", __PACKAGE__; }
    sub on_add    { say "add stage: ",    __PACKAGE__; }
    sub on_modify { say "modify stage: ", __PACKAGE__; }
    sub on_exit   { say "exit stage: ",   __PACKAGE__; }

    1;

The Fifth Column: Taskwarrior::Kusarigama::Hook::OnCommand

Kusarigama defines a fifth hook role, Taskwarrior::Kusarigama::Hook::OnCommand, to help creating custom commands. This role does two things: when task-kusarigama install is run, it creates a dummy report such that Taskwarrior will accept task my_custom_command as a valid invocation, and then it runs as part of the launch stage and will run the plugin code if the associated command was used.

Adding custom fields to tasks

Taskwarrior allows the creation of User-Defined Attributes (UDAs). Plugins can implement a custom_uda attribute that holds a hashref of new UDAs and their description. Those UDAs will then be fed to Taskwarrior's config via task-kusarigama install, and will thereafter be available like any other task field.

For example, Taskwarrior::Kusarigama::Plugin::Renew uses UDAs to identify tasks that should create a new, follow-up instance of themselves upon completion:

    package Taskwarrior::Kusarigama::Plugin::Renew;

    use strict;
    use warnings;

    use Clone 'clone';
    use List::AllUtils qw/ any /;

    use Moo;
    use MooseX::MungeHas;

    extends 'Taskwarrior::Kusarigama::Hook';

    with 'Taskwarrior::Kusarigama::Hook::OnExit';

    use experimental 'postderef';

    has custom_uda => sub{ +{
        renew => 'creates a follow-up task upon closing',
        rdue  => 'next task due date',
        rwait => 'next task wait period',
    } };

    sub on_exit {
        my( $self, @tasks ) = @_;

        return unless $self->command eq 'done';

        my $renewed;

        for my $task ( @tasks ) {
            next unless any { $task->{$_} } qw/ renew rdue rwait /;
            $renewed = 1;

            my $new = clone($task);

            delete $new->@{qw/ end modified entry status uuid /};

            my $due = $new->{rdue};
            $new->{due} = $self->calc($due) if $due;

            my $wait = $new->{rwait};
            $wait =~ s/due/$due/;
            $new->{wait} = $self->calc($wait) if $wait;

            $new->{status} = $wait ? 'waiting' : 'pending';

            $self->import_task($new);
        }

        $self .= 'created follow-up tasks' if $renewed;
    }

    1;

Aborting the pipeline

Any plugin can abort the taskwarrior process by simply dieing.

    sub on_add {
        my( $self, $task ) = @_;

        die "need jira ticket for work tasks"
            if $task->{project} eq 'work' and not $task->{jira};
    }

SEE ALSO

http://techblog.babyl.ca/entry/taskwarrior

the original blog entry

AUTHOR

Yanick Champoux <yanick@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2016 by Yanick Champoux.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.