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Corion / WWW-Mechanize-Chrome

automate the Chrome browser
https://metacpan.org/release/WWW-Mechanize-Chrome
Artistic License 2.0
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chrome mechanize perl

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CONTRIBUTING

See lib/WWW/Mechanize/Chrome/Contributing.pod

Google Keep Extraction

NAME

WWW::Mechanize::Chrome - automate the Chrome browser

SYNOPSIS

use Log::Log4perl qw(:easy);
use WWW::Mechanize::Chrome;

Log::Log4perl->easy_init($ERROR);  # Set priority of root logger to ERROR
my $mech = WWW::Mechanize::Chrome->new();
$mech->get('https://google.com');

$mech->eval_in_page('alert("Hello Chrome")');
my $png = $mech->content_as_png();

A collection of other Examples is available to help you get started.

DESCRIPTION

Like WWW::Mechanize, this module automates web browsing with a Perl object. Fetching and rendering of web pages is delegated to the Chrome (or Chromium) browser by starting an instance of the browser and controlling it with Chrome DevTools.

Advantages Over WWW::Mechanize

The Chrome browser provides advanced abilities useful for automating modern web applications that are not (yet) possible with WWW::Mechanize alone:

Disadvantages

Installation of a Chrome compatible browser is required. There are some quirks including sporadic, but harmless, error messages issued by the browser when run with with DevTools.

A Brief Operational Overview

WWW::Mechanize::Chrome (WMC) leverages developer tools built into Chrome and Chrome-like browsers to control a browser instance programatically. You can use WMC to automate tedious tasks, test web applications, and perform web scraping operations.

Typically, WMC is used to launch both a host instance of the browser and provide a client instance of the browser. The host instance of the browser is visible to you on your desktop (unless the browser is running in "headless" mode, in which case it will not open in a window). The client instance is the Perl program you write with the WMC module to issue commands to control the host instance. As you navigate and "click" on various nodes in the client browser, you watch the host browser respond to these actions as if by magic.

This magic happens as a result of commands that are issued from your client to the host using Chrome's DevTools Protocol which implements the http protocol to send JSON data structures. The host also responds to the client with JSON to describe the web pages it has loaded. WMC conveniently hides the complexity of the lower level communications between the client and host browsers and wraps them in a Perl object to provide the easy-to-use methods documented here.

OPTIONS

WWW::Mechanize::Chrome->new( %options )

my $mech = WWW::Mechanize::Chrome->new(
    headless => 0,
);

The $ENV{WWW_MECHANIZE_CHROME_TRANSPORT} variable can be set to a different transport class to override the default transport class. This is primarily used for testing but can also help eliminate introducing bugs from the underlying websocket implementation(s).

The $ENV{WWW_MECHANIZE_CHROME_CONNECTION_STYLE} variable can be set to either websocket or pipe to specify the kind of transport that you want to use.

The pipe transport is only available on unixish OSes and only with Chrome v72 onwards.

METHODS

WWW::Mechanize::Chrome->find_executable

my $chrome = WWW::Mechanize::Chrome->find_executable();

my $chrome = WWW::Mechanize::Chrome->find_executable(
    'chromium.exe',
    '.\\my-chrome-66\\',
);

my( $chrome, $diagnosis ) = WWW::Mechanize::Chrome->find_executable(
    ['chromium-browser','google-chrome'],
    './my-chrome-66/',
);
die $diagnosis if ! $chrome;

Finds the first Chrome executable in the path ($ENV{PATH}). For Windows, it also looks in $ENV{ProgramFiles}, $ENV{ProgramFiles(x86)} and $ENV{"ProgramFilesW6432"}. For OSX it also looks in the user home directory as given through $ENV{HOME}.

This is used to find the default Chrome executable if none was given through the launch_exe option or if the executable is given and does not exist and does not contain a directory separator.

$mech->chrome_version

print $mech->chrome_version;

Synonym for ->browser_version

$mech->browser_version

print $mech->browser_version;

Returns the version of the browser executable being used. This information needs launching the browser and asking for the version via the network.

$mech->chrome_version_info

print $mech->chrome_version_info->{product};

Returns the version information of the Chrome executable and various other APIs of Chrome that the object is connected to.

$mech->driver

deprecated - use ->target instead

my $driver = $mech->driver

Access the Chrome::DevToolsProtocol instance connecting to Chrome.

Deprecated, don't use this anymore. Most likely you want to use ->target to talk to the Chrome tab or ->transport to talk to the Chrome instance.

$mech->target

my $target = $mech->target

Access the Chrome::DevToolsProtocol::Target instance connecting to the Chrome tab we use.

$mech->transport

my $transport = $mech->transport

Access the Chrome::DevToolsProtocol::Transport instance connecting to the Chrome instance.

$mech->tab

my $tab = $mech->tab

Access the tab hash of the Chrome::DevToolsProtocol::Target instance. This represents the tab we control.

$mech->new_tab

$mech->new_tab_future

my $tab2 = $mech->new_tab_future(
    start_url => 'https://google.com',
)->get;

Creates a new tab (basically, a new WWW::Mechanize::Chrome object) connected to the same Chrome session.

# Use a targetInfo structure from Chrome
my $tab2 = $mech->new_tab_future(
    tab => {
        'targetId' => '1F42BDF32A30700805DDC21EDB5D8C4A',
    },
)->get;

It returns a Future because most event loops do not like recursing within themselves, which happens if you want to access a fresh new tab within another callback.

EVENTS

popup

my $opened;
$mech->on( 'popup' => sub( $mech, $tab_f ) {
    # This is a bit heavyweight, but ...
    $tab_f->on_done(sub($tab) {
        say "New window/tab was popped up:";
        $tab->uri_future->then(sub($uri) {
            say $uri;
        });
        $opened = $tab;
    })->retain;
});

$mech->click({ selector => '#popup_window' });
if( $opened ) {
    say $opened->title;
} else {
    say "Did not find new tab?";
};

This event is sent whenever a new tab/window gets popped up or created. The callback is handed the current and a second WWW::Mechanize::Chrome instance. Note that depending on your event loop, you are quite restricted on what synchronous methods you can call from within the callback.

$mech->allow( %options )

$mech->allow( javascript => 1 );

Allow or disallow execution of Javascript

$mech->emulateNetworkConditions( %options )

# Go offline
$mech->emulateNetworkConditions(
    offline => JSON::true,
    latency => 10, # ms ping
    downloadThroughput => 0, # bytes/s
    uploadThroughput => 0, # bytes/s
    connectionType => 'offline', # cellular2g, cellular3g, cellular4g, bluetooth, ethernet, wifi, wimax, other.
);

$mech->setRequestInterception( @patterns )

$mech->setRequestInterception(
    { urlPattern => '*', resourceType => 'Document', interceptionStage => 'Request'},
    { urlPattern => '*', resourceType => 'Media', interceptionStage => 'Response'},
);

Sets the list of request patterns and resource types for which the interception callback will be invoked.

$mech->continueInterceptedRequest( %options )

$mech->continueInterceptedRequest_future(
    interceptionId => ...
);

Continues an intercepted request

$mech->add_listener

my $url_loaded = $mech->add_listener('Network.responseReceived', sub {
    my( $info ) = @_;
    warn "Loaded URL "
         . $info->{params}->{response}->{url}
         . ": "
         . $info->{params}->{response}->{status};
    warn "Resource timing: " . Dumper $info->{params}->{response}->{timing};
});

Returns a listener object. If that object is discarded, the listener callback will be removed.

Calling this method in void context croaks.

To see the browser console live from your Perl script, use the following:

my $console = $mech->add_listener('Runtime.consoleAPICalled', sub {
  warn join ", ",
      map { $_->{value} // $_->{description} }
      @{ $_[0]->{params}->{args} };
});

If you want to explicitly remove the listener, either set it to undef:

undef $console;

Alternatively, call

$console->unregister;

or call

$mech->remove_listener( $console );

$mech->on_request_intercepted( $cb )

$mech->on_request_intercepted( sub {
    my( $mech, $info ) = @_;
    warn $info->{request}->{url};
    $mech->continueInterceptedRequest_future(
        interceptionId => $info->{interceptionId}
    )
});

A callback for intercepted requests that match the patterns set up via setRequestInterception.

If you return a future from this callback, it will not be discarded but kept in a safe place.

$mech->searchInResponseBody( $id, %options )

my $request_id = ...;
my @matches = $mech->searchInResponseBody(
    requestId     => $request_id,
    query         => 'rumpelstiltskin',
    caseSensitive => JSON::true,
    isRegex       => JSON::false,
);
for( @matches ) {
    print $_->{lineNumber}, ":", $_->{lineContent}, "\n";
};

Returns the matches (if any) for a string or regular expression within a response.

$mech->on_dialog( $cb )

$mech->on_dialog( sub {
    my( $mech, $dialog ) = @_;
    warn $dialog->{message};
    $mech->handle_dialog( 1 ); # click "OK" / "yes" instead of "cancel"
});

A callback for Javascript dialogs (alert(), prompt(), ... )

$mech->handle_dialog( $accept, $prompt = undef )

$mech->on_dialog( sub {
    my( $mech, $dialog ) = @_;
    warn "[Javascript $dialog->{type}]: $dialog->{message}";
    $mech->handle_dialog( 1 ); # click "OK" / "yes" instead of "cancel"
});

Closes the current Javascript dialog.

$mech->js_console_entries()

print $_->{type}, " ", $_->{message}, "\n"
    for $mech->js_console_entries();

An interface to the Javascript Error Console

Returns the list of entries in the JEC

$mech->js_errors()

print "JS error: ", $_->{message}, "\n"
    for $mech->js_errors();

Returns the list of errors in the JEC

$mech->clear_js_errors()

$mech->clear_js_errors();

Clears all Javascript messages from the console

$mech->eval_in_page( $str, %options )

$mech->eval( $str, %options )

my ($value, $type) = $mech->eval( '2+2' );

Evaluates the given Javascript fragment in the context of the web page. Returns a pair of value and Javascript type.

This allows access to variables and functions declared "globally" on the web page.

This method is special to WWW::Mechanize::Chrome.

$mech->eval_in_chrome $code, @args

$mech->eval_in_chrome(<<'JS', "Foobar/1.0");
    this.settings.userAgent= arguments[0]
JS

Evaluates Javascript code in the context of Chrome.

This allows you to modify properties of Chrome.

This is currently not implemented.

$mech->callFunctionOn( $function, @arguments )

my ($value, $type) = $mech->callFunctionOn(
    'function(greeting) { window.alert(greeting)}',
    objectId => $someObjectId,
    arguments => [{ value => 'Hello World' }]
);

Runs the given function with the specified arguments. This is the only way to pass arguments to a function call without doing risky string interpolation. The Javascript this object will be set to the object referenced from the objectId.

The arguments option expects an arrayref of hashrefs. Each hash describes one function argument.

The objectId parameter is optional. Leaving out the objectId parameter will create a dummy object on which the function then is called.

This method is special to WWW::Mechanize::Chrome.

->autoclose_tab

Set the autoclose option

->close

$mech->close()

Tear down all connections and shut down Chrome.

$mech->list_tabs

my @open_tabs = $mech->list_tabs()->get;
say $open_tabs[0]->{title};

Returns the open tabs as a list of hashrefs.

$mech->highlight_node( @nodes )

my @links = $mech->selector('a');
$mech->highlight_node(@links);
print $mech->content_as_png();

Convenience method that marks all nodes in the arguments with a red frame.

This is convenient if you need visual verification that you've got the right nodes.

NAVIGATION METHODS

$mech->get( $url, %options )

my $response = $mech->get( $url );

Retrieves the URL URL.

It returns a HTTP::Response object for interface compatibility with WWW::Mechanize.

Note that the returned HTTP::Response object gets the response body filled in lazily, so you might have to wait a moment to get the response body from the result. This is a premature optimization and later releases of WWW::Mechanize::Chrome are planned to fetch the response body immediately when accessing the response body.

Note that Chrome does not support download of files through the API.

Options

$mech->_collectEvents

my $events = $mech->_collectEvents(
    sub { $_[0]->{method} eq 'Page.loadEventFired' }
);
my( $e,$r) = Future->wait_all( $events, $self->target->send_message(...));

Internal method to create a Future that waits for an event that is sent by Chrome.

The subroutine is the predicate to check to see if the current event is the event we have been waiting for.

The result is a Future that will return all captured events.

$mech->get_local( $filename , %options )

$mech->get_local('test.html');

Shorthand method to construct the appropriate file:// URI and load it into Chrome. Relative paths will be interpreted as relative to $0 or the basedir option.

This method accepts the same options as ->get().

This method is special to WWW::Mechanize::Chrome but could also exist in WWW::Mechanize through a plugin.

Warning: Chrome does not handle local files well. Especially subframes do not get loaded properly.

$mech->getRequestPostData

if( $info->{params}->{response}->{requestHeaders}->{":method"} eq 'POST' ) {
    $req->{postBody} = $m->getRequestPostData( $id );
};

Retrieves the data sent with a POST request

$mech->post( $url, %options )

not implemented

$mech->post( 'http://example.com',
    params => { param => "Hello World" },
    headers => {
      "Content-Type" => 'application/x-www-form-urlencoded',
    },
    charset => 'utf-8',
);

Sends a POST request to $url.

A Content-Length header will be automatically calculated if it is not given.

The following options are recognized:

$mech->reload( %options )

$mech->reload( ignoreCache => 1 )

Acts like the reload button in a browser: repeats the current request. The history (as per the "back" method) is not altered.

Returns the HTTP::Response object from the reload, or undef if there's no current request.

$mech->set_download_directory( $dir )

my $downloads = tempdir();
$mech->set_download_directory( $downloads );

Enables automatic file downloads and sets the directory where the files will be downloaded to. Setting this to undef will disable downloads again.

The directory in $dir must be an absolute path, since Chrome does not know about the current directory of your Perl script.

$mech->cookie_jar

my $cookies = $mech->cookie_jar

Returns all the Chrome cookies in a HTTP::Cookies::ChromeDevTools instance. Setting a cookie in there will also set the cookie in Chrome. Note that the ->cookie_jar does not automatically refresh when a new page is loaded. To manually refresh the state of the cookie jar, use:

$mech->get('https://example.com/some_page');
$mech->cookie_jar->load;

$mech->add_header( $name => $value, ... )

$mech->add_header(
    'X-WWW-Mechanize-Chrome' => "I'm using it",
    Encoding => 'text/klingon',
);

This method sets up custom headers that will be sent with every HTTP(S) request that Chrome makes.

Note that currently, we only support one value per header.

Chrome since version 63+ does not allow setting and sending the Referer header anymore. The bug report is at https://bugs.chromium.org/p/chromium/issues/detail?id=849972.

$mech->delete_header( $name , $name2... )

$mech->delete_header( 'User-Agent' );

Removes HTTP headers from the agent's list of special headers. Note that Chrome may still send a header with its default value.

$mech->reset_headers

$mech->reset_headers();

Removes all custom headers and makes Chrome send its defaults again.

$mech->block_urls()

$mech->block_urls( '//facebook.com/js/conversions/tracking.js' );

Sets the list of blocked URLs. These URLs will not be retrieved by Chrome when loading a page. This is useful to eliminate tracking images or to test resilience in face of bad network conditions.

$mech->res() / $mech->response(%options)

my $response = $mech->response(headers => 0);

Returns the current response as a HTTP::Response object.

$mech->success()

$mech->get('https://google.com');
print "Yay"
    if $mech->success();

Returns a boolean telling whether the last request was successful. If there hasn't been an operation yet, returns false.

This is a convenience function that wraps $mech->res->is_success.

$mech->status()

$mech->get('https://google.com');
print $mech->status();
# 200

Returns the HTTP status code of the response. This is a 3-digit number like 200 for OK, 404 for not found, and so on.

$mech->back()

$mech->back();

Goes one page back in the page history.

Returns the (new) response.

$mech->forward()

$mech->forward();

Goes one page forward in the page history.

Returns the (new) response.

$mech->stop()

$mech->stop();

Stops all loading in Chrome, as if you pressed ESC.

This function is mostly of use in callbacks or in a timer callback from your event loop.

$mech->uri()

$mech->uri_future()

print "We are at " . $mech->uri;
print "We are at " . $mech->uri_future->get;

Returns the current document URI.

$mech->infinite_scroll( [$wait_time_in_seconds] )

$new_content_found = $mech->infinite_scroll(3);

Loads content into pages that have "infinite scroll" capabilities by scrolling to the bottom of the web page and waiting up to the number of seconds, as set by the optional $wait_time_in_seconds argument, for the browser to load more content. The default is to wait up to 20 seconds. For reasonbly fast sites, the wait time can be set much lower.

The method returns a boolean true if new content is loaded, false otherwise. You can scroll to the end (if there is one) of an infinitely scrolling page like so:

while( $mech->infinite_scroll ) {
    # Tests for exiting the loop earlier
    last if $count++ >= 10;
}

CONTENT METHODS

$mech->document_future()

$mech->document()

print $self->document->{nodeId};

Returns the document node.

This is WWW::Mechanize::Chrome specific.

$mech->content( %options )

print $mech->content;
print $mech->content( format => 'html' ); # default
print $mech->content( format => 'text' ); # identical to ->text
print $mech->content( format => 'mhtml' ); # identical to ->captureSnapshot

This always returns the content as a Unicode string. It tries to decode the raw content according to its input encoding. This currently only works for HTML pages, not for images etc.

Recognized options:

$mech->text()

print $mech->text();

Returns the text of the current HTML content. If the content isn't HTML, $mech will die.

$mech->captureSnapshot_future()

$mech->captureSnapshot()

print $mech->captureSnapshot( format => 'mhtml' )->{data};

Returns the current page as MHTML.

This is WWW::Mechanize::Chrome specific.

$mech->content_encoding()

print "The content is encoded as ", $mech->content_encoding;

Returns the encoding that the content is in. This can be used to convert the content from UTF-8 back to its native encoding.

$mech->update_html( $html )

$mech->update_html($html);

Writes $html into the current document. This is mostly implemented as a convenience method for HTML::Display::MozRepl.

The value passed in as $html will be stringified.

$mech->base()

print $mech->base;

Returns the URL base for the current page.

The base is either specified through a base tag or is the current URL.

This method is specific to WWW::Mechanize::Chrome.

$mech->content_type()

$mech->ct()

print $mech->content_type;

Returns the content type of the currently loaded document

$mech->is_html()

print $mech->is_html();

Returns true/false on whether our content is HTML, according to the HTTP headers.

$mech->title()

print "We are on page " . $mech->title;

Returns the current document title.

EXTRACTION METHODS

$mech->links()

print $_->text . " -> " . $_->url . "\n"
    for $mech->links;

Returns all links in the document as WWW::Mechanize::Link objects.

Currently accepts no parameters. See ->xpath or ->selector when you want more control.

$mech->selector( $css_selector, %options )

my @text = $mech->selector('p.content');

Returns all nodes matching the given CSS selector. If $css_selector is an array reference, it returns all nodes matched by any of the CSS selectors in the array.

This takes the same options that ->xpath does.

This method is implemented via WWW::Mechanize::Plugin::Selector.

$mech->find_link_dom( %options )

print $_->{innerHTML} . "\n"
    for $mech->find_link_dom( text_contains => 'CPAN' );

A method to find links, like WWW::Mechanize's ->find_links method. This method returns DOM objects from Chrome instead of WWW::Mechanize::Link objects.

Note that Chrome might have reordered the links or frame links in the document so the absolute numbers passed via n might not be the same between WWW::Mechanize and WWW::Mechanize::Chrome.

The supported options are:

$mech->find_link( %options )

print $_->text . "\n"
    for $mech->find_link( text_contains => 'CPAN' );

A method quite similar to WWW::Mechanize's method. The options are documented in ->find_link_dom.

Returns a WWW::Mechanize::Link object.

This defaults to not look through child frames.

$mech->find_all_links( %options )

print $_->text . "\n"
    for $mech->find_all_links( text_regex => qr/google/i );

Finds all links in the document. The options are documented in ->find_link_dom.

Returns them as list or an array reference, depending on context.

This defaults to not look through child frames.

$mech->find_all_links_dom %options

print $_->{innerHTML} . "\n"
    for $mech->find_all_links_dom( text_regex => qr/google/i );

Finds all matching linky DOM nodes in the document. The options are documented in ->find_link_dom.

Returns them as list or an array reference, depending on context.

This defaults to not look through child frames.

$mech->follow_link( $link )

$mech->follow_link( %options )

$mech->follow_link( xpath => '//a[text() = "Click here!"]' );

Follows the given link. Takes the same parameters that find_link_dom uses.

Note that ->follow_link will only try to follow link-like things like A tags.

$mech->xpath( $query, %options )

my $link = $mech->xpath('//a[id="clickme"]', one => 1);
# croaks if there is no link or more than one link found

my @para = $mech->xpath('//p');
# Collects all paragraphs

my @para_text = $mech->xpath('//p/text()', type => $mech->xpathResult('STRING_TYPE'));
# Collects all paragraphs as text

Runs an XPath query in Chrome against the current document.

If you need more information about the returned results, use the ->xpathEx() function.

Note that Chrome sometimes returns a node with node id 0. This node then cannot be found again using the Chrome API. This is bad luck and results in a warning.

The options allow the following keys:

Returns the matched results as WWW::Mechanize::Chrome::Node objects.

You can pass in a list of queries as an array reference for the first parameter. The result will then be the list of all elements matching any of the queries.

This is a method that is not implemented in WWW::Mechanize.

In the long run, this should go into a general plugin for WWW::Mechanize.

$mech->by_id( $id, %options )

my @text = $mech->by_id('_foo:bar');

Returns all nodes matching the given ids. If $id is an array reference, it returns all nodes matched by any of the ids in the array.

This method is equivalent to calling ->xpath :

$self->xpath(qq{//*[\@id="$_"]}, %options)

It is convenient when your element ids get mistaken for CSS selectors.

$mech->click( $name [,$x ,$y] )

# If the element is within a <form> element
$mech->click( 'go' );

# If the element is anywhere on the page
$mech->click({ xpath => '//button[@name="go"]' });

Has the effect of clicking a button (or other element) on the current form. The first argument is the name of the button to be clicked. The second and third arguments (optional) allow you to specify the (x,y) coordinates of the click.

If there is only one button on the form, $mech->click() with no arguments simply clicks that one button.

If you pass in a hash reference instead of a name, the following keys are recognized:

Returns a HTTP::Response object.

As a deviation from the WWW::Mechanize API, you can also pass a hash reference as the first parameter. In it, you can specify the parameters to search much like for the find_link calls.

$mech->click_button( ... )

$mech->click_button( name => 'go' );
$mech->click_button( input => $mybutton );

Has the effect of clicking a button on the current form by specifying its name, value, or index. Its arguments are a list of key/value pairs. Only one of name, number, input or value must be specified in the keys.

If you find yourself wanting to specify a button through its selector or xpath, consider using ->click instead.

FORM METHODS

$mech->current_form()

print $mech->current_form->{name};

Returns the current form.

This method is incompatible with WWW::Mechanize. It returns the DOM <form> object and not a HTML::Form instance.

The current form will be reset by WWW::Mechanize::Chrome on calls to ->get() and ->get_local(), and on calls to ->submit() and ->submit_with_fields.

$mech->dump_forms( [$fh] )

open my $fh, '>', 'form-log.txt'
    or die "Couldn't open logfile 'form-log.txt': $!";
$mech->dump_forms( $fh );

Prints a dump of the forms on the current page to the filehandle $fh. If $fh is not specified or is undef, it dumps to STDOUT.

$mech->form_name( $name [, %options] )

$mech->form_name( 'search' );

Selects the current form by its name. The options are identical to those accepted by the "$mech->xpath" method.

$mech->form_id( $id [, %options] )

$mech->form_id( 'login' );

Selects the current form by its id attribute. The options are identical to those accepted by the "$mech->xpath" method.

This is equivalent to calling

$mech->by_id($id,single => 1,%options)

$mech->form_number( $number [, %options] )

$mech->form_number( 2 );

Selects the _number_th form. The options are identical to those accepted by the "$mech->xpath" method.

$mech->form_with_fields( [$options], @fields )

$mech->form_with_fields(
    'user', 'password'
);

Find the form which has the listed fields.

If the first argument is a hash reference, it's taken as options to ->xpath.

See also "$mech->submit_form".

$mech->forms( %options )

my @forms = $mech->forms();

When called in a list context, returns a list of the forms found in the last fetched page. In a scalar context, returns a reference to an array with those forms.

The options are identical to those accepted by the "$mech->selector" method.

The returned elements are the DOM <form> elements.

$mech->field( $selector, $value, [, $index, \@pre_events [,\@post_events]] )

$mech->field( user => 'joe' );
$mech->field( not_empty => '', 0, [], [] ); # bypass JS validation
$mech->field( date => '2020-04-01', 2 );    # set second field named "date"

Sets the field with the name given in $selector to the given value. Returns the value.

The method understands very basic CSS selectors in the value for $selector, like the HTML::Form find_input() method.

A selector prefixed with '#' must match the id attribute of the input. A selector prefixed with '.' matches the class attribute. A selector prefixed with '^' or with no prefix matches the name attribute.

By passing the array reference @pre_events, you can indicate which Javascript events you want to be triggered before setting the value. @post_events contains the events you want to be triggered after setting the value.

By default, the events set in the constructor for pre_events and post_events are triggered.

$mech->sendkeys( %options )

$mech->sendkeys( string => "Hello World" );

Sends a series of keystrokes. The keystrokes can be either a string or a reference to an array containing the detailed data as hashes.

$mech->upload( $selector, $value )

$mech->upload( user_picture => 'C:/Users/Joe/face.png' );

Sets the file upload field with the name given in $selector to the given file. The filename must be an absolute path and filename in the local filesystem.

The method understands very basic CSS selectors in the value for $selector, like the ->field method.

$mech->value( $selector_or_element, [ $index | %options] )

print $mech->value( 'user' );

Returns the value of the field given by $selector_or_name or of the DOM element passed in.

If you have multiple fields with the same name, you can use the index to specify the index directly:

print $mech->value( 'date', 2 ); # get the second field named "date"

The legacy form of

$mech->value( name => value );

is not supported anymore.

For fields that can have multiple values, like a select field, the method is context sensitive and returns the first selected value in scalar context and all values in list context.

Note that this method does not support file uploads. See the ->upload method for that.

$mech->get_set_value( %options )

Allows fine-grained access to getting/setting a value with a different API. Supported keys are:

name
value
pre
post

in addition to all keys that $mech->xpath supports.

$mech->set_field( %options )

$mech->set_field(
    field => $field_node,
    value => 'foo',
);

Low level value setting method. Use this if you have an input element outside of a <form> tag.

$mech->select( $name, $value )

$mech->select( $name, \@values )

$mech->select( 'items', 'banana' );

Given the name of a select field, set its value to the value specified. If the field is not <select multiple> and the $value is an array, only the first value will be set. Passing $value as a hash with an n key selects an item by number (e.g. {n => 3} or {n => [2,4]}). The numbering starts at 1. This applies to the current form.

If you have a field with <select multiple> and you pass a single $value, then $value will be added to the list of fields selected, without clearing the others. However, if you pass an array reference, then all previously selected values will be cleared.

Returns true on successfully setting the value. On failure, returns false and calls $self>warn() with an error message.

$mech->tick( $name, $value [, $set ] )

$mech->tick("confirmation_box", 'yes');

"Ticks" the first checkbox that has both the name and value associated with it on the current form. Dies if there is no named check box for that value. Passing in a false value as the third optional argument will cause the checkbox to be unticked.

(Un)ticking the checkbox is done by sending a click event to it if needed. If $value is undef, the first checkbox matching $name will be (un)ticked.

If $name is a reference to a hash, that hash will be used as the options to ->find_link_dom to find the element.

$mech->untick( $name, $value )

$mech->untick('spam_confirm','yes',undef)

Causes the checkbox to be unticked. Shorthand for

$mech->tick($name,$value,undef)

$mech->submit( $form )

$mech->submit;

Submits the form. Note that this does not fire the onClick event and thus also does not fire eventual Javascript handlers. Maybe you want to use $mech->click instead.

The default is to submit the current form as returned by $mech->current_form.

$mech->submit_form( %options )

$mech->submit_form(
    with_fields => {
        user => 'me',
        pass => 'secret',
    }
);

This method lets you select a form from the previously fetched page, fill in its fields, and submit it. It combines the form_number/form_name, ->set_fields and ->click methods into one higher level call. Its arguments are a list of key/value pairs, all of which are optional.

$mech->set_fields( $name => $value, ... )

$mech->set_fields(
    user => 'me',
    pass => 'secret',
);

This method sets multiple fields of the current form. It takes a list of field name and value pairs. If there is more than one field with the same name, the first one found is set. If you want to select which of the duplicate field to set, use a value which is an anonymous array which has the field value and its number as the 2 elements.

$mech->set_fields(
    user => 'me',
    pass => 'secret',
    pass => [ 'secret', 2 ], # repeated password field
);

CONTENT MONITORING METHODS

$mech->is_visible( $element )

$mech->is_visible( %options )

if ($mech->is_visible( selector => '#login' )) {
    print "You can log in now.";
};

Returns true if the element is visible, that is, it is a member of the DOM and neither it nor its ancestors have a CSS visibility attribute of hidden or a display attribute of none.

You can either pass in a DOM element or a set of key/value pairs to search the document for the element you want.

The remaining options are passed through to either the /$mech->xpath or /$mech->selector method.

$mech->wait_until_invisible( $element )

$mech->wait_until_invisible( %options )

$mech->wait_until_invisible( $please_wait );

Waits until an element is not visible anymore.

Takes the same options as "->is_visible" in $mech->is_visible.

In addition, the following options are accepted:

Note that when passing in a selector, that selector is requeried on every poll instance. So the following query will work as expected:

xpath => '//*[contains(text(),"stand by")]'

This also means that if your selector query relies on finding a changing text, you need to pass the node explicitly instead of passing the selector.

$mech->wait_until_visible( %options )

$mech->wait_until_visible( selector => 'a.download' );

Waits until an query returns a visible element.

Takes the same options as "->is_visible" in $mech->is_visible.

In addition, the following options are accepted:

Note that when passing in a selector, that selector is requeried on every poll instance. So the following query will work as expected:

xpath => '//*[contains(text(),"click here for download")]'

CONTENT RENDERING METHODS

$mech->content_as_png()

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

# Create scaled-down 480px wide preview
my $png_data = $mech->content_as_png(undef, { width => 480 });

Returns the given tab or the current page rendered as PNG image.

All parameters are optional.

This method is specific to WWW::Mechanize::Chrome.

$mech->saveResources_future

my $file_map = $mech->saveResources_future(
    target_file => 'this_page.html',
    target_dir  => 'this_page_files/',
    wanted      => sub { $_[0]->{url} =~ m!^https?:!i },
)->get();

Rough prototype of "Save Complete Page" feature

$mech->viewport_size

print Dumper $mech->viewport_size;
$mech->viewport_size({ width => 1388, height => 792 });

Returns (or sets) the new size of the viewport (the "window").

The recognized keys are:

width
height
deviceScaleFactor
mobile
screenWidth
screenHeight
positionX
positionY

$mech->element_as_png( $element )

my $shiny = $mech->selector('#shiny', single => 1);
my $i_want_this = $mech->element_as_png($shiny);

Returns PNG image data for a single element

$mech->render_element( %options )

my $shiny = $mech->selector('#shiny', single => 1);
my $i_want_this= $mech->render_element(
    element => $shiny,
    format => 'png',
);

Returns the data for a single element or writes it to a file. It accepts all options of ->render_content.

Note that while the image will have the node in the upper left corner, the width and height of the resulting image will still be the size of the browser window. Cut the image using element_coordinates if you need exactly the element.

$mech->element_coordinates( $element )

my $shiny = $mech->selector('#shiny', single => 1);
my ($pos) = $mech->element_coordinates($shiny);
print $pos->{left},',', $pos->{top};

Returns the page-coordinates of the $element in pixels as a hash with four entries, left, top, width and height.

This function might get moved into another module more geared towards rendering HTML.

$mech->render_content(%options)

my $pdf_data = $mech->render_content( format => 'pdf' );

Returns the current page rendered as PDF or PNG as a bytestring.

Note that the PDF format will only be successful with headless Chrome. At least on Windows, when launching Chrome with a UI, printing to PDF will be unavailable.

This method is specific to WWW::Mechanize::Chrome.

$mech->content_as_pdf(%options)

my $pdf_data = $mech->content_as_pdf();

my $pdf_data = $mech->content_as_pdf( format => 'A4' );

my $pdf_data = $mech->content_as_pdf( paperWidth => 8, paperHeight => 11 );

Returns the current page rendered in PDF format as a bytestring. The page format can be specified through the format option.

Note that this method will only be successful with headless Chrome. At least on Windows, when launching Chrome with a UI, printing to PDF will be unavailable. See the html-to-pdf.pl script in the examples/ directory of this distribution.

This method is specific to WWW::Mechanize::Chrome.

INTERNAL METHODS

These are methods that are available but exist mostly as internal helper methods. Use of these is discouraged.

$mech->element_query( \@elements, \%attributes )

my $query = $mech->element_query(['input', 'select', 'textarea'],
                           { name => 'foo' });

Returns the XPath query that searches for all elements with tagNames in @elements having the attributes %attributes. The @elements will form an or condition, while the attributes will form an and condition.

DEBUGGING METHODS

This module can collect the screencasts that Chrome can produce. The screencasts are sent to your callback which either feeds them to ffmpeg to create a video out of them or dumps them to disk as sequential images.

sub saveFrame {
    my( $mech, $framePNG ) = @_;
    print $framePNG->{data};

}

$mech->setScreenFrameCallback( \&saveFrame );
... do stuff ...
$mech->setScreenFrameCallback( undef ); # stop recording

If you want a premade screencast receiver for debugging headless Chrome sessions, see Mojolicious::Plugin::PNGCast.

$mech->sleep

$mech->sleep( 2 ); # wait for things to settle down

Suspends the progress of the program while still handling messages from Chrome.

The main use of this method is to give Chrome enough time to send all its screencast frames and to catch up before shutting down the connection.

INCOMPATIBILITIES WITH WWW::Mechanize

As this module is in a very early stage of development, there are many incompatibilities. The main thing is that only the most needed WWW::Mechanize methods have been implemented by me so far.

Unsupported Methods

At least the following methods are unsupported:

Functions that will likely never be implemented

These functions are unlikely to be implemented because they make little sense in the context of Chrome.

INSTALLING

See WWW::Mechanize::Chrome::Install

SEE ALSO

MASQUERADING AS OTHER BROWSERS

Some articles about what you need to change to appear as a different browser

https://multilogin.com/why-mimicking-a-device-is-almost-impossible/

https://github.com/berstend/puppeteer-extra/tree/master/packages/puppeteer-extra-plugin-stealth

REPOSITORY

The public repository of this module is https://github.com/Corion/www-mechanize-chrome.

SUPPORT

The public support forum of this module is https://perlmonks.org/.

TALKS

I've given a German talk at GPW 2017, see http://act.yapc.eu/gpw2017/talk/7027 and https://corion.net/talks for the slides.

At The Perl Conference 2017 in Amsterdam, I also presented a talk, see http://act.perlconference.org/tpc-2017-amsterdam/talk/7022. The slides for the English presentation at TPCiA 2017 are at https://corion.net/talks/WWW-Mechanize-Chrome/www-mechanize-chrome.en.html.

At the London Perl Workshop 2017 in London, I also presented a talk, see Youtube . The slides for that talk are here.

BUG TRACKER

Please report bugs in this module via the Github bug queue at https://github.com/Corion/WWW-Mechanize-Chrome/issues

CONTRIBUTING

Please see WWW::Mechanize::Chrome::Contributing.

KNOWN ISSUES

Please see WWW::Mechanize::Chrome::Troubleshooting.

AUTHOR

Max Maischein corion@cpan.org

CONTRIBUTORS

Andreas König andk@cpan.org

Tobias Leich froggs@cpan.org

Steven Dondley s@dondley.org

Joshua Pollack

COPYRIGHT (c)

Copyright 2010-2024 by Max Maischein corion@cpan.org.

LICENSE

This module is released under the same terms as Perl itself.