perl/AUR/Json.pm

   1 package AUR::Json;
   2 use strict;
   3 use warnings;
   4 use v5.20;
   5
   6 use Exporter qw(import);
   7 our @EXPORT_OK = qw(parse_json parse_json_aur write_json);
   8 our $VERSION = 'unstable';
   9
  10 =head1 NAME
  11
  12 AUR::Json - Perl interface to AurJson
  13
  14 =head1 SYNOPSIS
  15
  16   use AUR::Json qw(parse_json_aur write_json);
  17
  18   my $json;
  19   my @results = parse_json_aur($json);
  20   my $object  = parse_json($json);
  21   my $str     = write_json($object);
  22
  23 =head1 DESCRIPTION
  24
  25 This module provides Perl aur(1) scripts a coherent way to deal with
  26 AurJson responses. In particular, parse_json_aur() returns an array of
  27 package results for variable AUR inputs (both from AurJson and
  28 metadata archives.
  29
  30 If JSON::XS is available, this module will use it for JSON
  31 parsing. JSON::PP shipped with Perl is used as a fallback.
  32
  33 TODO: The interface is in its early stages and is prone to change in
  34 later versions. Possible additions include AUR types for common use
  35 with aur-format(1) and aur-search(1).
  36
  37 =head1 AUTHORS
  38
  39 Alad Wenter <https://github.com/AladW/aurutils>
  40
  41 =cut
  42
  43 our $aur_json;
  44
  45 # Fallback to slower perl-based JSON parsing
  46 if (eval { require JSON::XS; 1 }) {
  47     $aur_json = JSON::XS->new;
  48 }
  49 else {
  50     require JSON::PP;
  51     $aur_json = JSON::PP->new;
  52 }
  53
  54 =head2 parse_json()
  55
  56 =cut
  57
  58 sub parse_json {
  59     my $str = shift;
  60     my $obj = $aur_json->incr_parse($str)
  61         or die __PACKAGE__ . ": expected JSON object or array at beginning of string";
  62     $aur_json->incr_reset();
  63
  64     return $obj;
  65 }
  66
  67 =head2 parse_json_aur()
  68
  69 =cut
  70
  71 sub parse_json_aur {
  72     my $str = shift;
  73     my $obj = parse_json($str);
  74
  75     # Possible AUR responses:
  76     # - JSON arrays: REST (suggests), metadata archives (packages-meta-v1.json)
  77     # - JSON hashes, `results` array: REST (info, search)
  78     # - JSON hashes: `repo-parse` (JSONL)
  79     if (ref($obj) eq 'HASH' and defined($obj->{'results'})) {
  80         my $error = $obj->{'error'};
  81
  82         if (defined($error)) {
  83             say STDERR __PACKAGE__ . ': response error (' . $error . ')';
  84             exit(4);
  85         }
  86         return @{$obj->{'results'}};
  87     }
  88     elsif (ref($obj) eq 'HASH') {
  89         return ($obj);
  90     }
  91     elsif (ref($obj) eq 'ARRAY') {
  92         return @{$obj};
  93     }
  94     else {
  95         say STDERR __PACKAGE__ . ": not an array or hash";
  96         exit(4);
  97     }
  98 }
  99
 100 =head2 write_json()
 101
 102 =cut
 103
 104 sub write_json {
 105     my $obj = shift;
 106     my $str = $aur_json->canonical()->encode($obj);
 107     return $str;
 108 }
 109
 110 # vim: set et sw=4 sts=4 ft=perl: