http://qs321.pair.com?node_id=11115779


in reply to Re^2: running an example script with WWW::Mechanize* module
in thread running an example script with WWW::Mechanize* module

There is a misunderstanding of $mech->success - this method only reflects whether the last HTTP response from the server is considered an error or not. It does not reflect whether the last operation on $mech was successful or not. Error checking is usually done by die by WWW::Mechanize::Chrome.

I haven't run your code, but the log output suggests that the form you're looking at has no name:

  say $mech->current_form->{name};    # ??
  # Use of uninitialized value in say at ./5.pluto.pl line 55.

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The form is not great, because it really contains three fields with the same name date, so you will have to fetch the individual fields and explicitly set them:

# largely untested
my @date_fields = $mech->selector('.//*[@name="date"]', node => $self-
+>current_form );
$mech->set_field( $date_fields[1] => $guess );

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In the next version, I'll actually implement the arrayref form of ->set_fields() for values of index larger than one :) But that means breaking my (incompatible) API to restore the WWW::Mechanize API so I'll have to look carefully there.

 $mech->set_fields( $name => [ 'foo', 2 ] );

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Re^4: running an example script with WWW::Mechanize* module
by Aldebaran (Curate) on Apr 21, 2020 at 03:22 UTC
    The form is not great, because it really contains three fields with the same name date, so you will have to fetch the individual fields and explicitly set them:

    Thanks, Corion, I think we're almost there. I've got this pared down as far as I can to make an SSCCE. I can't get perl to think I have a valid selector:

    $ ./6.1.pluto.pl 
say (...) interpreted as function at ./6.1.pluto.pl line 47.
2020/04/20 20:10:39 Connected to ws://127.0.0.1:40757/devtools/browser
+/10f7d706-4dbd-4073-a438-916f6602fb4c
found the one and only form
Invalid rule, couldn't parse '//*[@name="date", node => $mech->current
+_form ]' at /usr/local/share/perl/5.26.1/HTML/Selector/XPath.pm line 
+283.
$

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    Source, with the critical line tried several different ways:

    #! /usr/bin/perl
use warnings;
use strict;
use WWW::Mechanize::Chrome;
use Log::Log4perl qw(:easy);
use Data::Dump;
use 5.016;

Log::Log4perl->easy_init($INFO);

my $site =
'https://www.fourmilab.ch/cgi-bin/Yoursky?z=1&lat=45.5183&ns=North&lon
+=122.676&ew=West';
my $mech = WWW::Mechanize::Chrome->new( headless => 1, );
$mech->get($site);

my $guess = 2458960;    #Earth day 2020 in julian days

$mech->form_number(1);
say "found the one and only form"
  if $mech->success();

# my best guess...aka...trial 1
# $mech->field( date => '2', jd => $guess );
# stderr: 3 elements found for input with name 'date' at ./6.1.pluto.p
+l line 21.

# your first guess...aka trial 2
# my @date_fields =$mech->selector( './/*[@name="date"]', node => $sel
+f->current_form );
# stderr: Global symbol "$self" requires explicit package name 

# 3rd guess
#my @date_fields =$mech->selector( './/*[@name="date"]', node => $mech
+->current_form );

# stderr: Invalid rule, couldn't parse '//*[@name="date"]' at /usr/loc
+al/share/perl/5.26.1/HTML/Selector/XPath.pm line 283.

# 4th guess
# my @date_fields =$mech->selector( './/*[@name="date", node => $self-
+>current_form ]');
# stderr: Invalid rule, couldn't parse '//*[@name="date", node => $sel
+f->current_form ]' 

# 5th guess
my @date_fields =$mech->selector( './/*[@name="date", node => $mech->c
+urrent_form ]');

# Invalid rule, couldn't parse '//*[@name="date", node => $mech->curre
+nt_form ]'

$mech->set_field( $date_fields[1] => $guess );

$mech->click_button( value => "Update" );    # this seems similar to W
+M
say "clickbutton succeeded"
  if $mech->success();
my $string = $mech->uri;
say ("We are at $string")
  if $mech->success();

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    That lays it out there as starkly as I can. VielenDank und Gruss aus Amiland.

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      Invalid rule, couldn't parse '//*[@name="date", node => $mech->current
+_form ]'

      [download]

      This looks as if you're mixing Perl code and an XPath expression in the same string.

       my @date_fields =$mech->selector( './/*[@name="date"]', node => $mech
+->current_form );
# stderr: Invalid rule, couldn't parse '//*[@name="date"]' at /usr/loc
+al/share/perl/5.26.1/HTML/Selector/XPath.pm line 283.

      [download]

      This is weird - I think this should still parse as an XPath expression. Does the following work and give the expected result?

       my @date_fields =$mech->xpath( './/*[@name="date"]', node => $mech->c
+urrent_form );

      [download]

      With version 0.48 of WWW::Mechanize::Chrome, ->set_fields now also supports selecing input elements by their name and index:

      $mech->set_fields(
    date => [3, $date_value],
);

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