CODEWITHSUNDEEP
perlwww-mechanize
aks
aks

Reputation: 1359

How can I recover from a timeout with Perl's WWW::Mechanize?

I'm using WWW::Mechanize to read a particular webpage in a loop that runs every few seconds. Occasionally, the 'GET' times out and the script stops running. How can I recover from one such timeout such that it continues the loop and tries the 'GET' the next time around?

Upvotes: 6

Views: 1873

Answers (4)

Trenton
Trenton

Reputation: 11986

For a more complete solution, you can use a module like Try::Tiny::Retry. It allows you to specify a code block to run, catches any errors, then retries that code block a configurable amount of time. The syntax is pretty clean.

use WWW::Mechanize();
use Try::Tiny::Retry ':all';

my $mech = WWW::Mechanize->new();
retry {
    $mech->get("https://stackoverflow.com/");
}
on_retry {
    warn("Failed. Retrying. Error was: $_");
}
delay {
    # max of 100 tries, sleeping 5 seconds between each failure
    return if $_[0] >= 100;
    sleep(11 * 1000 * 1000);
}; #don't forget this semicolon

# dump all the links found on the page
print join "\n", map {$_->text } $mech->links;

Upvotes: 0

Brett Pennings
Brett Pennings

Reputation: 1499

This solution will continue to attempt to load the page until it works.

do {
    eval {
        $mech->get($url);
    };
} while ($@ ne '');

Upvotes: 0

Eugene Yarmash
Eugene Yarmash

Reputation: 149776

Use eval :

eval {
    my $resp = $mech->get($url);
    $resp->is_success or die $resp->status_line;
    # your code
};

if ($@) {
    print "Recovered from a GET error\n";    
}

The eval block will catch any error while GETing the page.

Upvotes: 4

martin clayton
martin clayton

Reputation: 78105

One option would be to implement a method to handle timeout errors and hook it into the mech object at construction time as the onerror handler. See Constructor and Startup in the docs.

You could even ignore errors by setting a null error handler, for example:

my $mech = WWW::Mechanize->new( onerror => undef );

but I wouldn't recommend that - you'll just get weird problems later.

Upvotes: 1

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