summaryrefslogtreecommitdiffstats
path: root/lib/Reply/Plugin/ReadLine.pm
blob: 899d563030e74a436547482c302761e949d511af (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
package Reply::Plugin::ReadLine;
use strict;
use warnings;
# ABSTRACT: use Term::ReadLine for user input

use base 'Reply::Plugin';

use File::HomeDir;
use File::Spec;
use Scalar::Util 'weaken';
use Term::ReadLine;

=head1 SYNOPSIS

  ; .replyrc
  [ReadLine]
  history_file = '.hist'
  history_length = 100

=head1 DESCRIPTION

This plugin uses L<Term::ReadLine> to read lines from the user. This enables
useful features such as line editing and command history. The history will be
persisted between runs, by default in C<~/.reply_history>, although this is
changeable with the C<history_file> option. To limit the number of lines
written to this file, you can use the C<history_length> option. Setting a
C<history_length> of C<0> will disable writing history to a file entirely.

NOTE: you probably want to install a reasonable L<Term::ReadLine> backend in
order for this plugin to be very useful. L<Term::ReadLine::Gnu> is highly
recommended if possible.

=cut

sub new {
    my $class = shift;
    my %opts = @_;

    my $self = $class->SUPER::new(@_);
    $self->{term} = Term::ReadLine->new('Reply');
    my $history = $opts{history_file} || '.reply_history';
    $self->{history_file} = File::Spec->catfile(
        (File::Spec->file_name_is_absolute($history)
            ? ()
            : (File::HomeDir->my_data)),
        $history
    );

    $self->{rl_gnu} = $self->{term}->ReadLine eq 'Term::ReadLine::Gnu';
    $self->{rl_perl5} = $self->{term}->ReadLine eq 'Term::ReadLine::Perl5';

    if ($self->{rl_perl5}) {
        # output compatible with Term::ReadLine::Gnu
        $readline::rl_scroll_nextline = 0;
    }

    if ($self->{rl_perl5} || $self->{rl_gnu}) {
        $self->{term}->StifleHistory($opts{history_length})
            if defined $opts{history_length} && $opts{history_length} >= 0;
    }

    if (open my $fh, '<', $self->{history_file}) {
        for my $line (<$fh>) {
            chomp $line;
            $self->{term}->addhistory($line);
        }
    }
    else {
        my $e = $!;
        warn "Couldn't open $self->{history_file} for reading: $e"
            if -e $self->{history_file};
    }

    $self->_register_tab_complete;

    return $self;
}

sub read_line {
    my $self = shift;
    my ($next, $prompt) = @_;

    return $self->{term}->readline($prompt);
}

sub DESTROY {
    my $self = shift;

    return if defined $self->{history_length} && $self->{history_length} == 0;

    # XXX support more later
    return unless ($self->{rl_gnu} || $self->{rl_perl5});

    $self->{term}->WriteHistory($self->{history_file})
        or warn "Couldn't write history to $self->{history_file}";
}

sub _register_tab_complete {
    my $self = shift;

    my $term = $self->{term};

    weaken(my $weakself = $self);

    if ($self->{rl_gnu}) {
        $term->Attribs->{attempted_completion_function} = sub {
            my ($text, $line, $start, $end) = @_;

            # discard everything after the cursor for completion purposes
            substr($line, $end) = '';

            my @matches = $weakself->publish('tab_handler', $line);
            my $match_index = 0;

            return $term->completion_matches($text, sub {
                my ($text, $index) = @_;
                return $matches[$index];
            });
        };
    }

    if ($self->{rl_perl5}) {
        $term->Attribs->{completion_function} = sub {
            my ($text, $line, $start) = @_;
            my $end = $start + length($text);

            # discard everything after the cursor for completion purposes
            substr($line, $end) = '';

            my @matches = $weakself->publish('tab_handler', $line);
            return scalar(@matches) ? @matches : ();
        };
    }
}

1;