Fetching JSON in Perl

Question

I've been working building an emulator in Perl and one of the issues I'm facing is parsing JSON files located in the computer. When I try fetching them from my server, they work fine...

    method getContent(\@arrURLS) {
    my %arrInfo;
    my $resUserAgent = Mojo::UserAgent->new;
    foreach my $strURL (@arrURLS) {
        $resUserAgent->get($strURL => sub {
            my($resUserAgent, $tx) = @_;
            if ($tx->success) {
                my $strName = basename($strURL, '.json');
                my $arrData = $tx->res->body;
                $arrInfo{$strName} = $arrData;
            }
            Mojo::IOLoop->stop;
        });
        Mojo::IOLoop->start;
    }
    return \%arrInfo;
}

Let's assume @arrURLS is:

my @arrURLS = ("file:///C:/Users/Test/Desktop/JSONS/first.json", "file:///C:/Users/Test/Desktop/JSONS/second.json");

The above url's are the one's that aren't working, however if I change that to:

my @arrURLS = ("http://127.0.0.1/test/json/first.json", "http://127.0.0.1/test/json/second.json");

it works.

Also I would like to use something better than Mojo::UserAgent because it seems a bit slow, when I was using Coro with LWP::Simple it was much faster but unfortunately Coro is broken in Perl 5.22...

Answer 1

User Agents are mainly for downloading files through http. They are usually not expected to handle filesystem URIs. You need to open and read the file yourself, or use a module like File::Slurp that does it for you.

It could look something like this.

use File::Slurp 'read_file';

method getContent(\@arrURLS) {
    my %arrInfo;
    my $resUserAgent = Mojo::UserAgent->new;
    foreach my $strURL (@arrURLS) {
        if (substr($strURL, 0, 4) eq 'file') {
            $arrInfo{basename($strURL, '.json')} = read_file($strURL);
        } else {
            $resUserAgent->get($strURL => sub {
                my($resUserAgent, $tx) = @_;
                if ($tx->success) {
                    my $strName = basename($strURL, '.json');
                    my $arrData = $tx->res->body;
                    $arrInfo{$strName} = $arrData;
                }
                Mojo::IOLoop->stop;
            });
            Mojo::IOLoop->start;
        }
    }
    return \%arrInfo;
}