search

libwww-perl / WWW-Mechanize

Handy web browsing in a Perl object
https://metacpan.org/pod/WWW::Mechanize
Other
68 stars 53 forks source link
hacktoberfest

readme

NAME

WWW::Mechanize - Handy web browsing in a Perl object

VERSION

version 2.19

SYNOPSIS

WWW::Mechanize supports performing a sequence of page fetches including following links and submitting forms. Each fetched page is parsed and its links and forms are extracted. A link or a form can be selected, form fields can be filled and the next page can be fetched. Mech also stores a history of the URLs you've visited, which can be queried and revisited.

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

$mech->get( $url );

$mech->follow_link( n => 3 );
$mech->follow_link( text_regex => qr/download this/i );
$mech->follow_link( url => 'http://host.com/index.html' );

$mech->submit_form(
    form_number => 3,
    fields      => {
        username    => 'mungo',
        password    => 'lost-and-alone',
    }
);

$mech->submit_form(
    form_name => 'search',
    fields    => { query  => 'pot of gold', },
    button    => 'Search Now'
);

# Enable strict form processing to catch typos and non-existent form fields.
my $strict_mech = WWW::Mechanize->new( strict_forms => 1);

$strict_mech->get( $url );

# This method call will die, saving you lots of time looking for the bug.
$strict_mech->submit_form(
    form_number => 3,
    fields      => {
        usernaem     => 'mungo',           # typo in field name
        password     => 'lost-and-alone',
        extra_field  => 123,               # field does not exist
    }
);

DESCRIPTION

WWW::Mechanize, or Mech for short, is a Perl module for stateful programmatic web browsing, used for automating interaction with websites.

Features include:

Mech is well suited for use in testing web applications. If you use one of the Test::*, like Test::HTML::Lint modules, you can check the fetched content and use that as input to a test call.

use Test::More;
like( $mech->content(), qr/$expected/, "Got expected content" );

Each page fetch stores its URL in a history stack which you can traverse.

$mech->back();

If you want finer control over your page fetching, you can use these methods. [follow_link()](#mech-follow_link) and [submit_form()](#mech-submit_form) are just high level wrappers around them.

$mech->find_link( n => $number );
$mech->form_number( $number );
$mech->form_name( $name );
$mech->field( $name, $value );
$mech->set_fields( %field_values );
$mech->set_visible( @criteria );
$mech->click( $button );

WWW::Mechanize is a proper subclass of LWP::UserAgent and you can also use any of LWP::UserAgent's methods.

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

Please note that Mech does NOT support JavaScript, you need additional software for that. Please check "JavaScript" in WWW::Mechanize::FAQ for more.

IMPORTANT LINKS

CONSTRUCTOR AND STARTUP

new()

Creates and returns a new WWW::Mechanize object, hereafter referred to as the "agent".

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

The constructor for WWW::Mechanize overrides two of the params to the LWP::UserAgent constructor:

agent => 'WWW-Mechanize/#.##'
cookie_jar => {}    # an empty, memory-only HTTP::Cookies object

You can override these overrides by passing params to the constructor, as in:

my $mech = WWW::Mechanize->new( agent => 'wonderbot 1.01' );

If you want none of the overhead of a cookie jar, or don't want your bot accepting cookies, you have to explicitly disallow it, like so:

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

Here are the params that WWW::Mechanize recognizes. These do not include params that LWP::UserAgent recognizes.

In addition, WWW::Mechanize also allows you to globally enable strict and verbose mode for form handling, which is done with HTML::Form.

To support forms, WWW::Mechanize's constructor pushes POST on to the agent's requests_redirectable list (see also LWP::UserAgent.)

$mech->agent_alias( $alias )

Sets the user agent string to the expanded version from a table of actual user strings. $alias can be one of the following:

then it will be replaced with a more interesting one. For instance,

$mech->agent_alias( 'Windows IE 6' );

sets your User-Agent to

Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)

The list of valid aliases can be returned from [known_agent_aliases()](#mech-known_agent_aliases). The current list is:

$mech->known_agent_aliases()

Returns a list of all the agent aliases that Mech knows about. This can also be called as a package or class method.

@aliases = WWW::Mechanize::known_agent_aliases();
@aliases = WWW::Mechanize->known_agent_aliases();
@aliases = $mech->known_agent_aliases();

PAGE-FETCHING METHODS

$mech->get( $uri )

Given a URL/URI, fetches it. Returns an HTTP::Response object. $uri can be a well-formed URL string, a URI object, or a WWW::Mechanize::Link object.

The results are stored internally in the agent object, but you don't know that. Just use the accessors listed below. Poking at the internals is deprecated and subject to change in the future.

get() is a well-behaved overloaded version of the method in LWP::UserAgent. This lets you do things like

$mech->get( $uri, ':content_file' => $filename );

and you can rest assured that the params will get filtered down appropriately. See "get" in LWP::UserAgent for more details.

NOTE: The file in :content_file will contain the raw content of the response. If the response content is encoded (e.g. gzip encoded), the file will be encoded as well. Use $mech->save_content if you need the decoded content.

NOTE: Because :content_file causes the page contents to be stored in a file instead of the response object, some Mech functions that expect it to be there won't work as expected. Use with caution.

Here is a non-complete list of methods that do not work as expected with :content_file: [forms()](#mech-forms), [current_form()](#mech-current_form), [links()](#mech-links), [title()](#mech-title), [content(...)](#mech-content), [text()](#mech-text), all content-handling methods, all link methods, all image methods, all form methods, all field methods, [save_content(...)](#mech-save_content-filename-opts), [dump_links(...)](#mech-dump_links-fh-absolute), [dump_images(...)](#mech-dump_images-fh-absolute), [dump_forms(...)](#mech-dump_forms-fh), [dump_text(...)](#mech-dump_text-fh)

$mech->post( $uri, content => $content )

POSTs $content to $uri. Returns an HTTP::Response object. $uri can be a well-formed URI string, a URI object, or a WWW::Mechanize::Link object.

$mech->put( $uri, content => $content )

PUTs $content to $uri. Returns an HTTP::Response object. $uri can be a well-formed URI string, a URI object, or a WWW::Mechanize::Link object.

my $res = $mech->put( $uri );
my $res = $mech->put( $uri , $field_name => $value, ... );

$mech->head ($uri )

Performs a HEAD request to $uri. Returns an HTTP::Response object. $uri can be a well-formed URI string, a URI object, or a WWW::Mechanize::Link object.

$mech->delete ($uri )

Performs a DELETE request to $uri. Returns an HTTP::Response object. $uri can be a well-formed URI string, a URI object, or a WWW::Mechanize::Link object.

$mech->reload()

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->back()

The equivalent of hitting the "back" button in a browser. Returns to the previous page. Won't go back past the first page. (Really, what would it do if it could?)

Returns true if it could go back, or false if not.

$mech->clear_history()

This deletes all the history entries and returns true.

$mech->history_count()

This returns the number of items in the browser history. This number does include the most recently made request.

$mech->history($n)

This returns the _n_th item in history. The 0th item is the most recent request and response, which would be acted on by methods like [find_link()](#mech-find_link). The 1st item is the state you'd return to if you called [back()](#mech-back).

The maximum useful value for $n is $mech->history_count - 1. Requests beyond that bound will return undef.

History items are returned as hash references, in the form:

{ req => $http_request, res => $http_response }

STATUS METHODS

$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->uri()

Returns the current URI as a URI object. This object stringifies to the URI itself.

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

Return the current response as an HTTP::Response object.

Synonym for $mech->response().

$mech->status()

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->ct() / $mech->content_type()

Returns the content type of the response.

$mech->base()

Returns the base URI for the current response

$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 forms returned are all HTML::Form objects.

$mech->current_form()

Returns the current form as an HTML::Form object.

$mech->links()

When called in a list context, returns a list of the links found in the last fetched page. In a scalar context it returns a reference to an array with those links. Each link is a WWW::Mechanize::Link object.

$mech->is_html()

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

$mech->title()

Returns the contents of the <TITLE> tag, as parsed by HTML::HeadParser. Returns undef if the content is not HTML.

$mech->redirects()

Convenience method to get the redirects from the most recent HTTP::Response.

Note that you can also use is_redirect to see if the most recent response was a redirect like this.

$mech->get($url);
do_stuff() if $mech->res->is_redirect;

CONTENT-HANDLING METHODS

$mech->content(...)

Returns the content that the mech uses internally for the last page fetched. Ordinarily this is the same as $mech->response()->decoded_content(), but this may differ for HTML documents if [update_html](#mech-update_html-html) is overloaded (in which case the value passed to the base-class implementation of same will be returned), and/or extra named arguments are passed to content():

To preserve backwards compatibility, additional parameters will be ignored unless none of raw | decoded_by_headers | charset is specified and the text is HTML, in which case an error will be triggered.

A fresh instance of WWW::Mechanize will return undef when $mech->content() is called, because no content is present before a request has been made.

$mech->text()

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

The text is extracted by parsing the content, and then the extracted text is cached, so don't worry about performance of calling this repeatedly.

LINK METHODS

$mech->links()

Lists all the links on the current page. Each link is a WWW::Mechanize::Link object. In list context, returns a list of all links. In scalar context, returns an array reference of all links.

$mech->follow_link(...)

Follows a specified link on the page. You specify the match to be found using the same params that [find_link()](#mech-find_link) uses.

Here some examples:

Returns the result of the GET method (an HTTP::Response object) if a link was found.

If the page has no links, or the specified link couldn't be found, returns undef. If autocheck is enabled an exception will be thrown instead.

$mech->find_link( ... )

Finds a link in the currently fetched page. It returns a WWW::Mechanize::Link object which describes the link. (You'll probably be most interested in the [url()](https://metacpan.org/pod/WWW%3A%3AMechanize%3A%3ALink#link-url) property.) If it fails to find a link it returns undef.

You can take the URL part and pass it to the get() method. If that's your plan, you might as well use the [follow_link()](#mech-follow_link) method directly, since it does the get() for you automatically.

Note that <FRAME SRC="..."> tags are parsed out of the HTML and treated as links so this method works with them.

You can select which link to find by passing in one or more of these key/value pairs:

If n is not specified, it defaults to 1. Therefore, if you don't specify any params, this method defaults to finding the first link on the page.

Note that you can specify multiple text or URL parameters, which will be ANDed together. For example, to find the first link with text of "News" and with "cnn.com" in the URL, use:

$mech->find_link( text => 'News', url_regex => qr/cnn\.com/ );

The return value is a reference to an array containing a WWW::Mechanize::Link object for every link in [$self->content](#mech-content).

The links come from the following:

$mech->find_all_links( ... )

Returns all the links on the current page that match the criteria. The method for specifying link criteria is the same as in [find_link()](#mech-find_link). Each of the links returned is a WWW::Mechanize::Link object.

In list context, find_all_links() returns a list of the links. Otherwise, it returns a reference to the list of links.

find_all_links() with no parameters returns all links in the page.

$mech->find_all_inputs( ... criteria ... )

find_all_inputs() returns an array of all the input controls in the current form whose properties match all of the regexes passed in. The controls returned are all descended from HTML::Form::Input. See "INPUTS" in HTML::Form for details.

If no criteria are passed, all inputs will be returned.

If there is no current page, there is no form on the current page, or there are no submit controls in the current form then the return will be an empty array.

You may use a regex or a literal string:

# get all textarea controls whose names begin with "customer"
my @customer_text_inputs = $mech->find_all_inputs(
    type       => 'textarea',
    name_regex => qr/^customer/,
);

# get all text or textarea controls called "customer"
my @customer_text_inputs = $mech->find_all_inputs(
    type_regex => qr/^(text|textarea)$/,
    name       => 'customer',
);

$mech->find_all_submits( ... criteria ... )

find_all_submits() does the same thing as [find_all_inputs()](#mech-find_all_inputs-criteria) except that it only returns controls that are submit controls, ignoring other types of input controls like text and checkboxes.

IMAGE METHODS

$mech->images

Lists all the images on the current page. Each image is a WWW::Mechanize::Image object. In list context, returns a list of all images. In scalar context, returns an array reference of all images.

$mech->find_image()

Finds an image in the current page. It returns a WWW::Mechanize::Image object which describes the image. If it fails to find an image it returns undef.

You can select which image to find by passing in one or more of these key/value pairs:

If n is not specified, it defaults to 1. Therefore, if you don't specify any params, this method defaults to finding the first image on the page.

Note that you can specify multiple ALT or URL parameters, which will be ANDed together. For example, to find the first image with ALT text of "News" and with "cnn.com" in the URL, use:

$mech->find_image( image => 'News', url_regex => qr/cnn\.com/ );

The return value is a reference to an array containing a WWW::Mechanize::Image object for every image in [$mech->content](#mech-content).

$mech->find_all_images( ... )

Returns all the images on the current page that match the criteria. The method for specifying image criteria is the same as in [find_image()](#mech-find_image). Each of the images returned is a WWW::Mechanize::Image object.

In list context, find_all_images() returns a list of the images. Otherwise, it returns a reference to the list of images.

find_all_images() with no parameters returns all images in the page.

FORM METHODS

These methods let you work with the forms on a page. The idea is to choose a form that you'll later work with using the field methods below.

$mech->forms

Lists all the forms on the current page. Each form is an HTML::Form object. In list context, returns a list of all forms. In scalar context, returns an array reference of all forms.

$mech->form_number($number)

Selects the _number_th form on the page as the target for subsequent calls to [field()](#mech-field-name-value-number) and [click()](#mech-click-button-x-y). Also returns the form that was selected.

If it is found, the form is returned as an HTML::Form object and set internally for later use with Mech's form methods such as [field()](#mech-field-name-value-number) and [click()](#mech-click-button-x-y). When called in a list context, the number of the found form is also returned as a second value.

Emits a warning and returns undef if no form is found.

The first form is number 1, not zero.

$mech->form_action( $action )

Selects a form by action, using a regex containing $action. If there is more than one form on the page matching that action, then the first one is used, and a warning is generated.

If it is found, the form is returned as an HTML::Form object and set internally for later use with Mech's form methods such as [field()](#mech-field-name-value-number) and [click()](#mech-click-button-x-y).

Returns undef if no form is found.

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

Selects a form by name.

By default, the first form that has this name will be returned.

my $form = $mech->form_name("order_form");

If you want the second, third or nth match, pass an optional arguments hash reference as the final parameter with a key n to pick which instance you want. The numbering starts at 1.

my $third_product_form = $mech->form_name("buy_now", { n => 3 });

If the n parameter is not passed, and there is more than one form on the page with that name, then the first one is used, and a warning is generated.

If it is found, the form is returned as an HTML::Form object and set internally for later use with Mech's form methods such as [field()](#mech-field-name-value-number) and [click()](#mech-click-button-x-y).

Returns undef if no form is found.

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

Selects a form by ID.

By default, the first form that has this ID will be returned.

my $form = $mech->form_id("order_form");

Although the HTML specification requires the ID to be unique within a page, some pages might not adhere to that. If you want the second, third or nth match, pass an optional arguments hash reference as the final parameter with a key n to pick which instance you want. The numbering starts at 1.

my $third_product_form = $mech->form_id("buy_now", { n => 3 });

If the n parameter is not passed, and there is more than one form on the page with that ID, then the first one is used, and a warning is generated.

If it is found, the form is returned as an HTML::Form object and set internally for later use with Mech's form methods such as [field()](#mech-field-name-value-number) and [click()](#mech-click-button-x-y).

If no form is found it returns undef. This will also trigger a warning, unless quiet is enabled.

$mech->all_forms_with_fields( @fields )

Selects a form by passing in a list of field names it must contain. All matching forms (perhaps none) are returned as a list of HTML::Form objects.

$mech->form_with_fields( @fields, [ \%args ] )

Selects a form by passing in a list of field names it must contain. By default, the first form that matches all of these field names will be returned.

my $form = $mech->form_with_fields( qw/sku quantity add_to_cart/ );

If you want the second, third or nth match, pass an optional arguments hash reference as the final parameter with a key n to pick which instance you want. The numbering starts at 1.

my $form = $mech->form_with_fields( 'sky', 'qty', { n => 2 } );

If the n parameter is not passed, and there is more than one form on the page with that ID, then the first one is used, and a warning is generated.

If it is found, the form is returned as an HTML::Form object and set internally for later used with Mech's form methods such as [field()](#mech-field-name-value-number) and [click()](#mech-click-button-x-y).

Returns undef and emits a warning if no form is found.

Note that this functionality requires libwww-perl 5.69 or higher.

$mech->all_forms_with( $attr1 => $value1, $attr2 => $value2, ... )

Searches for forms with arbitrary attribute/value pairs within the <form> tag. When given more than one pair, all criteria must match. Using undef as value means that the attribute in question must not be present.

All matching forms (perhaps none) are returned as a list of HTML::Form objects.

$mech->form_with( $attr1 => $value1, $attr2 => $value2, ..., [ \%args ] )

Searches for forms with arbitrary attribute/value pairs within the <form> tag. When given more than one pair, all criteria must match. Using undef as value means that the attribute in question must not be present.

By default, the first form that matches all criteria will be returned.

my $form = $mech->form_with( name => 'order_form', method => 'POST' );

If you want the second, third or nth match, pass an optional arguments hash reference as the final parameter with a key n to pick which instance you want. The numbering starts at 1.

my $form = $mech->form_with( method => 'POST', { n => 4 } );

If the n parameter is not passed, and there is more than one form on the page matching these criteria, then the first one is used, and a warning is generated.

If it is found, the form is returned as an HTML::Form object and set internally for later used with Mech's form methods such as [field()](#mech-field-name-value-number) and [click()](#mech-click-button-x-y).

Returns undef if no form is found.

FIELD METHODS

These methods allow you to set the values of fields in a given form.

$mech->field( $name, $value, $number )

$mech->field( $name, \@values, $number )

$mech->field( $name, \@file_upload_values, $number )

Given the name of a field, set its value to the value specified. This applies to the current form (as set by the [form_name()](#mech-form_name-name-args) or [form_number()](#mech-form_number-number) method or defaulting to the first form on the page).

If the field is of type "file", its value should be an arrayref. Example:

$mech->field( $file_input, ['/tmp/file.txt'] );

Value examples for "file" inputs, followed by explanation of what each index mean:

# 0: filepath      1: filename    3: headers
['/tmp/file.txt']
['/tmp/file.txt', 'filename.txt']
['/tmp/file.txt', 'filename.txt', @headers]
['/tmp/file.txt', 'filename.txt', Content => 'some content']
[undef,           'filename.txt', Content => 'content here']

Index 0 is the filepath that will be read from disk. Index 1 is the filename which will be used in the HTTP request body; if not given, filepath (index 0) is used instead. If Content => 'content here' is used as shown, then filepath will be ignored.

The optional $number parameter is used to distinguish between two fields with the same name. The fields are numbered from 1.

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

$mech->select($name, \%new_single_value_by_number)

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

$mech->select($name, \%new_list_of_values_by_number)

Given the name of a select field, set its value to the value specified.

# select 'foo'
$mech->select($name, 'foo');

If the field is not <select multiple> and the $value is an array reference, only the first value will be set. [Note: until version 1.05_03 the documentation claimed that only the last value would be set, but this was incorrect.]

# select 'bar'
$mech->select($name, ['bar', 'ignored', 'ignored']);

Passing $value as a hash reference with an n key selects an item by number.

# select the third value
$mech->select($name, {n => 3});

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.

# add 'bar' to the list of selected values
$mech->select($name, 'bar');

However, if you pass an array reference, then all previously selected values will be cleared and replaced with all values inside the array reference.

# replace the selection with 'foo' and 'bar'
$mech->select($name, ['foo', 'bar']);

This also works when selecting by numbers, in which case the value of the n key will be an array reference of value numbers you want to replace the selection with.

# replace the selection with the 2nd and 4th element
$mech->select($name, {n => [2, 4]});

To add multiple additional values to the list of selected fields without clearing, call select in the simple $value form with each single value in a loop.

# add all values in the array to the selection
$mech->select($name, $_) for @additional_values;

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

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

$mech->set_fields( $name => \@value_and_instance_number )

$mech->set_fields( $name => \$value_instance_number )

$mech->set_fields( $name => \@file_upload )

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.

    # set the second $name field to 'foo'
    $mech->set_fields( $name => [ 'foo', 2 ] );

The value of a field of type "file" should be an arrayref as described in [field()](https://metacpan.org/pod/%24mech-%3Efield%28%20%24name%2C%20%24value%2C%20%24number%20%29). Examples:

    $mech->set_fields( $file_field => ['/tmp/file.txt'] );
    $mech->set_fields( $file_field => ['/tmp/file.txt', 'filename.txt'] );

The value for a "file" input can also be an arrayref containing an arrayref and a number, as documented in [submit_form()](https://metacpan.org/pod/%24mech-%3Esubmit_form%28%20...%20%29). The number will be used to find the field in the form. Example:

    $mech->set_fields( $file_field => [['/tmp/file.txt'], 1] );

The fields are numbered from 1.

For fields that have a predefined set of values, you may also provide a reference to an integer, if you don't know the options for the field, but you know you just want (e.g.) the first one.

    # select the first value in the $name select box
    $mech->set_fields( $name => \0 );
    # select the last value in the $name select box
    $mech->set_fields( $name => \-1 );

This applies to the current form.

$mech->set_visible( @criteria )

This method sets fields of the current form without having to know their names. So if you have a login screen that wants a username and password, you do not have to fetch the form and inspect the source (or use the mech-dump utility, installed with WWW::Mechanize) to see what the field names are; you can just say

$mech->set_visible( $username, $password );

and the first and second fields will be set accordingly. The method is called set_visible because it acts only on visible fields; hidden form inputs are not considered. The order of the fields is the order in which they appear in the HTML source which is nearly always the order anyone viewing the page would think they are in, but some creative work with tables could change that; caveat user.

Each element in @criteria is either a field value or a field specifier. A field value is a scalar. A field specifier allows you to specify the type of input field you want to set and is denoted with an arrayref containing two elements. So you could specify the first radio button with

$mech->set_visible( [ radio => 'KCRW' ] );

Field values and specifiers can be intermixed, hence

$mech->set_visible( 'fred', 'secret', [ option => 'Checking' ] );

would set the first two fields to "fred" and "secret", and the next OPTION menu field to "Checking".

The possible field specifier types are: "text", "password", "hidden", "textarea", "file", "image", "submit", "radio", "checkbox" and "option".

set_visible returns the number of values set.

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

"Ticks" the first checkbox that has both the name and value associated with it on the current form. If there is no value to the input, just pass an empty string as the value. Dies if there is no named checkbox for the value given, if a value is given. Passing in a false value as the third optional argument will cause the checkbox to be unticked. The third value does not need to be set if you wish to merely tick the box.

$mech->tick('extra', 'cheese');
$mech->tick('extra', 'mushrooms');

$mech->tick('no_value', ''); # <input type="checkbox" name="no_value">

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

Causes the checkbox to be unticked. Shorthand for tick($name,$value,undef)

$mech->value( $name [, $number] )

Given the name of a field, return its value. This applies to the current form.

The optional $number parameter is used to distinguish between two fields with the same name. The fields are numbered from 1.

If the field is of type file (file upload field), the value is always cleared to prevent remote sites from downloading your local files. To upload a file, specify its file name explicitly.

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

Has the effect of clicking a button 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.

Returns an HTTP::Response object.

$mech->click_button( ... )

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

Dies if no button is found.

$mech->submit()

Submits the current form, without specifying a button to click. Actually, no button is clicked at all.

Returns an HTTP::Response object.

This used to be a synonym for $mech->click( 'submit' ), but is no longer so.

$mech->submit_form( ... )

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.

If no form is selected, the first form found is used.

If button is not passed, then the [submit()](#mech-submit) method is used instead.

If you want to submit a file and get its content from a scalar rather than a file in the filesystem, you can use:

$mech->submit_form(with_fields => { logfile => [ [ undef, 'whatever', Content => $content ], 1 ] } );

Returns an HTTP::Response object.

MISCELLANEOUS METHODS

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

Sets HTTP headers for the agent to add or remove from the HTTP request.

$mech->add_header( Encoding => 'text/klingon' );

If a value is undef, then that header will be removed from any future requests. For example, to never send a Referer header:

$mech->add_header( Referer => undef );

If you want to delete a header, use delete_header.

Returns the number of name/value pairs added.

NOTE: This method was very different in WWW::Mechanize before 1.00. Back then, the headers were stored in a package hash, not as a member of the object instance. Calling add_header() would modify the headers for every WWW::Mechanize object, even after your object no longer existed.

$mech->delete_header( name [, name ... ] )

Removes HTTP headers from the agent's list of special headers. For instance, you might need to do something like:

# Don't send a Referer for this URL
$mech->add_header( Referer => undef );

# Get the URL
$mech->get( $url );

# Back to the default behavior
$mech->delete_header( 'Referer' );

$mech->quiet(true/false)

Allows you to suppress warnings to the screen.

$mech->quiet(0); # turns on warnings (the default)
$mech->quiet(1); # turns off warnings
$mech->quiet();  # returns the current quietness status

$mech->autocheck(true/false)

Allows you to enable and disable autochecking.

Autocheck checks each request made to see if it was successful. This saves you the trouble of manually checking yourself. Any errors found are errors, not warnings. Please see [new](#new) for more details.

$mech->autocheck(1); # turns on automatic request checking (the default)
$mech->autocheck(0); # turns off automatic request checking
$mech->autocheck();  # returns the current autocheck status

$mech->stack_depth( $max_depth )

Get or set the page stack depth. Use this if you're doing a lot of page scraping and running out of memory.

A value of 0 means "no history at all." By default, the max stack depth is humongously large, effectively keeping all history.

$mech->save_content( $filename, %opts )

Dumps the contents of [$mech->content](#mech-content) into $filename. $filename will be overwritten. Dies if there are any errors.

If the content type does not begin with "text/", then the content is saved in binary mode (i.e. binmode() is set on the output filehandle).

Additional arguments can be passed as key/value pairs:

$mech->dump_headers( [$fh] )

Prints a dump of the HTTP response headers for the most recent response. If $fh is not specified or is undef, it dumps to STDOUT.

Unlike the rest of the dump_* methods, $fh can be a scalar. It will be used as a file name.

$mech->dump_links( [[$fh], $absolute] )

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

If $absolute is true, links displayed are absolute, not relative.

$mech->dump_images( [[$fh], $absolute] )

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

If $absolute is true, links displayed are absolute, not relative.

The output will include empty lines for images that have no src attribute and therefore no URL.

$mech->dump_forms( [$fh] )

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

my $mech = WWW::Mechanize->new();
$mech->get("https://www.google.com/");
$mech->dump_forms;

will print:

GET https://www.google.com/search [f]
  ie=ISO-8859-1                  (hidden readonly)
  hl=en                          (hidden readonly)
  source=hp                      (hidden readonly)
  biw=                           (hidden readonly)
  bih=                           (hidden readonly)
  q=                             (text)
  btnG=Google Search             (submit)
  btnI=I'm Feeling Lucky         (submit)
  gbv=1                          (hidden readonly)

$mech->dump_text( [$fh] )

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

OVERRIDDEN LWP::UserAgent METHODS

$mech->clone()

Clone the mech object. The clone will be using the same cookie jar as the original mech.

$mech->redirect_ok()

An overloaded version of redirect_ok() in LWP::UserAgent. This method is used to determine whether a redirection in the request should be followed.

Note that WWW::Mechanize's constructor pushes POST on to the agent's requests_redirectable list.

$mech->request( $request [, $arg [, $size]])

Overloaded version of request() in LWP::UserAgent. Performs the actual request. Normally, if you're using WWW::Mechanize, it's because you don't want to deal with this level of stuff anyway.

Note that $request will be modified.

Returns an HTTP::Response object.

$mech->update_html( $html )

Allows you to replace the HTML that the mech has found. Updates the forms and links parse-trees that the mech uses internally.

Say you have a page that you know has malformed output, and you want to update it so the links come out correctly:

my $html = $mech->content;
$html =~ s[</option>.{0,3}</td>][</option></select></td>]isg;
$mech->update_html( $html );

This method is also used internally by the mech itself to update its own HTML content when loading a page. This means that if you would like to systematically perform the above HTML substitution, you would overload update_html in a subclass thusly:

package MyMech;
use parent 'WWW::Mechanize';

sub update_html {
    my ($self, $html) = @_;
    $html =~ s[</option>.{0,3}</td>][</option></select></td>]isg;
    $self->WWW::Mechanize::update_html( $html );
}

If you do this, then the mech will use the tidied-up HTML instead of the original both when parsing for its own needs, and for returning to you through [content()](#mech-content).

Overloading this method is also the recommended way of implementing extra validation steps (e.g. link checkers) for every HTML page received. [warn](#warn-messages) and [warn](#warn-messages) would then come in handy to signal validation errors.

$mech->credentials( $username, $password )

Provide credentials to be used for HTTP Basic authentication for all sites and realms until further notice.

The four argument form described in LWP::UserAgent is still supported.

$mech->get_basic_credentials( $realm, $uri, $isproxy )

Returns the credentials for the realm and URI.

$mech->clear_credentials()

Remove any credentials set up with credentials().

INHERITED UNCHANGED LWP::UserAgent METHODS

As a subclass of LWP::UserAgent, WWW::Mechanize inherits all of LWP::UserAgent's methods. Many of which are overridden or extended. The following methods are inherited unchanged. View the LWP::UserAgent documentation for their implementation descriptions.

This is not meant to be an inclusive list. LWP::UA may have added others.

$mech->head()

Inherited from LWP::UserAgent.

$mech->mirror()

Inherited from LWP::UserAgent.

$mech->simple_request()

Inherited from LWP::UserAgent.

$mech->is_protocol_supported()

Inherited from LWP::UserAgent.

$mech->prepare_request()

Inherited from LWP::UserAgent.

$mech->progress()

Inherited from LWP::UserAgent.

INTERNAL-ONLY METHODS

These methods are only used internally. You probably don't need to know about them.

$mech->_update_page($request, $response)

Updates all internal variables in $mech as if $request was just performed, and returns $response. The page stack is not altered by this method, it is up to caller (e.g. [request](#mech-request-request-arg-size)) to do that.

$mech->_modify_request( $req )

Modifies a HTTP::Request before the request is sent out, for both GET and POST requests.

We add a Referer header, as well as header to note that we can accept gzip encoded content, if Compress::Zlib is installed.

$mech->_make_request()

Convenience method to make it easier for subclasses like WWW::Mechanize::Cached to intercept the request.

$mech->_reset_page()

Resets the internal fields that track page parsed stuff.

$mech->_extract_links()

Extracts links from the content of a webpage, and populates the {links} property with WWW::Mechanize::Link objects.

$mech->_push_page_stack()

The agent keeps a stack of visited pages, which it can pop when it needs to go BACK and so on.

The current page needs to be pushed onto the stack before we get a new page, and the stack needs to be popped when BACK occurs.

Neither of these take any arguments, they just operate on the $mech object.

warn( @messages )

Centralized warning method, for diagnostics and non-fatal problems. Defaults to calling CORE::warn, but may be overridden by setting onwarn in the constructor.

die( @messages )

Centralized error method. Defaults to calling CORE::die, but may be overridden by setting onerror in the constructor.

BEST PRACTICES

The default settings can get you up and running quickly, but there are settings you can change in order to make your life easier.

WWW::MECHANIZE'S GIT REPOSITORY

WWW::Mechanize is hosted at GitHub.

Repository: https://github.com/libwww-perl/WWW-Mechanize. Bugs: https://github.com/libwww-perl/WWW-Mechanize/issues.

OTHER DOCUMENTATION

Spidering Hacks, by Kevin Hemenway and Tara Calishain

Spidering Hacks from O'Reilly (http://www.oreilly.com/catalog/spiderhks/) is a great book for anyone wanting to know more about screen-scraping and spidering.

There are six hacks that use Mech or a Mech derivative:

The book was also positively reviewed on Slashdot: http://books.slashdot.org/article.pl?sid=03/12/11/2126256

ONLINE RESOURCES AND SUPPORT

ARTICLES ABOUT WWW::MECHANIZE

Other modules that use Mechanize

Here are modules that use or subclass Mechanize. Let me know of any others:

ACKNOWLEDGEMENTS

Thanks to the numerous people who have helped out on WWW::Mechanize in one way or another, including Kirrily Robert for the original WWW::Automate, Lyle Hopkins, Damien Clark, Ansgar Burchardt, Gisle Aas, Jeremy Ary, Hilary Holz, Rafael Kitover, Norbert Buchmuller, Dave Page, David Sainty, H.Merijn Brand, Matt Lawrence, Michael Schwern, Adriano Ferreira, Miyagawa, Peteris Krumins, Rafael Kitover, David Steinbrunner, Kevin Falcone, Mike O'Regan, Mark Stosberg, Uri Guttman, Peter Scott, Philippe Bruhat, Ian Langworth, John Beppu, Gavin Estey, Jim Brandt, Ask Bjoern Hansen, Greg Davies, Ed Silva, Mark-Jason Dominus, Autrijus Tang, Mark Fowler, Stuart Children, Max Maischein, Meng Wong, Prakash Kailasa, Abigail, Jan Pazdziora, Dominique Quatravaux, Scott Lanning, Rob Casey, Leland Johnson, Joshua Gatcomb, Julien Beasley, Abe Timmerman, Peter Stevens, Pete Krawczyk, Tad McClellan, and the late great Iain Truskett.

AUTHOR

Andy Lester <andy at petdance.com>

COPYRIGHT AND LICENSE

This software is copyright (c) 2004 by Andy Lester.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.