Perlbeginner1 has asked for the wisdom of the Perl Monks concerning the following question:

hya - good evening dear perl-folks want to grab screenshots from sites like the following.. 

www.google.com
   www.msnbc.com
    news.bbc.co.uk
    www.yahoo.com

[download]



for a mechanize-scraper i take this one here 

#!/usr/bin/perl
use strict;
use warnings;
use WWW::Mechanize::Firefox;

my $mech = new WWW::Mechanize::Firefox();

open(INPUT, "<url.txt") or die $!;

while (<INPUT>) {
        chomp;
        print "$_\n";
        $mech->get($_);
        my $png = $mech->content_as_png();
        my $name = "$_";
        $name =~s/^www\.//;
        $name .= ".png";
        open(OUTPUT, ">$name");
        print OUTPUT $png;
        sleep (5);
}

[download]



Well i forgot to mention that i only need to have the images as small thumbnails - so we do not have to have a very very large files...

i only need to grab a thumbnail screenshot of them. How do I do that?

my $png = $mech->content_as_png();

The line returns the given tab or the current page rendered as PNG image.
as the documentation states:

All parameters are optional. $tab defaults to the current tab. If the coordinates are given, that rectangle will be cut out. The coordinates should be a hash with the four usual entries, left,top,width,height. This is specific to WWW::Mechanize::Firefox.

Well does that have any impact on our code - can we make the code somewhat more specifical to our needs. Note:the files i store are a bit smaller - if we limit them after fetching from the web !? aren īt they!?

BTW; Currently, the data transfer between Firefox and Perl is done Base64-encoded, isn t it. Well It would be beneficial to find what 's necessary to make JSON handle all the binary data more gracefully what do you think. Love to hear from you

Now i try to install mozrepl - if you or anybody has got some tipps on that. should i run

a. zypper in .or

b. get it as a firefox plugin greetings

Replies are listed 'Best First'.
Re: Perl Mechanize issues - how to make a script running faster with less overhead
by Corion (Patriarch) on Feb 11, 2012 at 13:36 UTC
    You might want to make more clear which parts of your text are copied from the WWW::Mechanize::Firefox documentation and which parts are your own. Especially when the documentation answers your questions. See the examples included with WWW::Mechanize::Firefox for how to save screenshots. The module does not concern itself with resizing images. See the various image modules on CPAN, like Imager.
[reply]
      hello thx for all the hints

      greetings pb1
[reply]
Re: Perl Mechanize issues - how to make a script running faster with less overhead
by Anonymous Monk on Feb 11, 2012 at 11:18 UTC

    UTSL 

     sub content_as_png {
    my ($self, $tab, $rect) = @_;
    $tab ||= $self->tab;
    $rect ||= {};
    
    # Mostly taken from
    # http://wiki.github.com/bard/mozrepl/interactor-screenshot-server
    my $screenshot = $self->repl->declare(<<'JS');
    function (tab,rect) {
        var browser = tab.linkedBrowser;
        var browserWindow = Components.classes['@mozilla.org/appshell/
+window-mediator;1']
            .getService(Components.interfaces.nsIWindowMediator)
            .getMostRecentWindow('navigator:browser');
        var win = browser.contentWindow;
        var body = win.document.body;
        if(!body) {
            return;
        };
        var canvas = browserWindow
               .document
               .createElementNS('http://www.w3.org/1999/xhtml', 'canva
+s');
        var left = rect.left || 0;
        var top = rect.top || 0;
        var width = rect.width || body.clientWidth;
        var height = rect.height || body.clientHeight;
        canvas.width = width;
        canvas.height = height;
        var ctx = canvas.getContext('2d');
        ctx.clearRect(0, 0, width, height);
        ctx.save();
        ctx.scale(1.0, 1.0);
        ctx.drawWindow(win, left, top, width, height, 'rgb(255,255,255
+)');
        ctx.restore();

        //return atob(
        return canvas
               .toDataURL('image/png', '')
               .split(',')[1]
        // );
    }
JS
    my $scr = $screenshot->($tab, $rect);
    return $scr ? decode_base64($scr) : undef
};

    [download]

    Now i try to install mozrepl - if you or anybody has got some tipps on that. should i run

    Hire a sysadmin, seriously

[reply]
[d/l]

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