Re^4: Accessing javascript variable from perl

With the file ~~jello.js~~hello.js

var leg = {
aa: "Hello from javascript"
}

function to_json() {
   return JSON.stringify(leg);
}
[download]

And the file perl.pl

use strict;
use warnings;
use WWW::Mechanize::PhantomJS;
my $js = WWW::Mechanize::PhantomJS->new(launch_exe=> 'C:/prog/phantomj
+s/bin/phantomjs.exe');
$js->get_local("hello.js");
#$js->update_html('<script src="hello.js" type="text/javascript"></scr
+ipt>');
#print $js->content;
#my ($val, $type) = $js->eval_in_page('JSON.stringify(window.leg);');
my ($val, $type) = $js->eval_in_page('to_json()');
print "val: $val, type: $type\n";
[download]

I can't have any meaningfull result from calling eval_in_page either on the leg var directly or via the function.

Can you show me how to have this working ?

Thanks

Update without phantomjs

use strict;
use warnings;
use Log::Log4perl qw(:easy);
Log::Log4perl->easy_init($ERROR);
use WWW::Mechanize::Chrome;
my $js = WWW::Mechanize::Chrome->new(report_js_errors=>1);
$js->get_local("hello.js");
#$js->update_html('<script src="hello.js" type="text/javascript"></scr
+ipt>');
#print $js->content;
#my ($val, $type) = $js->eval_in_page('JSON.stringify(window.leg);');
my ($val, $type) = $js->eval_in_page('to_json()');
print "val: $val, type: $type\n";
[download]

This gives undef for $val whatever I'm calling: the to_json() function or JSON.stringify directly.

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Re^5: Accessing javascript variable from perl by LanX (Saint) on Jun 18, 2019 at 08:15 UTC
hello != jello > I can't have any meaningfull result ... Which error message do you get? I don't have phantomjs installed, so please provide a reproducible example. UPDATE I ran your JS code in the browser's console and it works for me: `> var leg = { aa: "Hello from javascript" } function to_json() { return JSON.stringify(leg); } < undefined > JSON.stringify(leg); < "{\"aa\":\"Hello from javascript\"}" > to_json() < "{\"aa\":\"Hello from javascript\"}"` [download] Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery FootballPerl is like chess, only without the dice}	[reply] [d/l]
Re^5: Accessing javascript variable from perl by LanX (Saint) on Jun 18, 2019 at 11:15 UTC
regarding your update: Neither do I have WWW::Mechanize::Chrome installed. My suggestions are to make sure your JS is really executed (add an alert to show) and this before you try eval_in_page (you could play around with sleep or a similar wait mechanism) HTH! Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery FootballPerl is like chess, only without the dice}	[reply]
Re^6: Accessing javascript variable from perl by frazap (Monk) on Jun 18, 2019 at 12:12 UTC
HTH Yes, it did: adding an `alert("hello from js");` in the js file show me that a (the only ?) way to have it executed, was to load an existing html file. Using `$js->modify_html('<script src="hello.js" type="text/javascript"></script>')`on a blank page did not run the js file. So, I have to load this `<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1 +"> <title>test</title> <script src="hello.js"></script> </head> <body> </body` [download] Then, the following worked: `my $js = WWW::Mechanize::PhantomJS->new(launch_exe=> 'C:/prog/phantomj +s/bin/phantomjs.exe'); #or #my $js = WWW::Mechanize::Chrome->new(report_js_errors=>1); $js->get_local("hello.html"); my ($val, $type) = $js->eval_in_page('JSON.stringify(window.leg);'); #or #my ($val, $type) = $js->eval_in_page('JSON.stringify(leg);'); #or #my ($val, $type) = $js->eval_in_page('to_json()'); print "val: ", Dumper($val), "type: $type\n";` [download] Thanks frazap	[reply] [d/l] [select]

UPDATE