WWW::Mechanize(3pm) User Contributed Perl Documentation WWW::Mechanize(3pm)NAMEWWW::Mechanize - Handy web browsing in a Perl object
VERSION
version 1.86
SYNOPSISWWW::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'
);
DESCRIPTION
"WWW::Mechanize", or Mech for short, is a Perl module for stateful
programmatic web browsing, used for automating interaction with
websites.
Features include:
· All HTTP methods
· High-level hyperlink and HTML form support, without having to parse
HTML yourself
· SSL support
· Automatic cookies
· Custom HTTP headers
· Automatic handling of redirections
· Proxies
· HTTP authentication
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" and "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
· <https://github.com/libwww-perl/WWW-Mechanize/issues>
The queue for bugs & enhancements in WWW::Mechanize and
Test::WWW::Mechanize. Please note that the queue at
<http://rt.cpan.org> is no longer maintained.
· <http://search.cpan.org/dist/WWW-Mechanize/>
The CPAN documentation page for Mechanize.
· <http://search.cpan.org/dist/WWW-Mechanize/lib/WWW/Mechanize/FAQ.pod>
Frequently asked questions. Make sure you read here FIRST.
CONSTRUCTOR AND STARTUPnew()
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 parms to the
LWP::UserAgent constructor:
agent => 'WWW-Mechanize/#.##'
cookie_jar => {} # an empty, memory-only HTTP::Cookies object
You can override these overrides by passing parms 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 $mech = WWW::Mechanize->new( cookie_jar => undef );
Here are the parms that WWW::Mechanize recognizes. These do not
include parms that LWP::UserAgent recognizes.
· "autocheck => [0|1]"
Checks each request made to see if it was successful. This saves
you the trouble of manually checking yourself. Any errors found
are errors, not warnings.
The default value is ON, unless it's being subclassed, in which
case it is OFF. This means that standalone WWW::Mechanize
instances have autocheck turned on, which is protective for the
vast majority of Mech users who don't bother checking the return
value of get() and post() and can't figure why their code fails.
However, if WWW::Mechanize is subclassed, such as for
Test::WWW::Mechanize or Test::WWW::Mechanize::Catalyst, this may
not be an appropriate default, so it's off.
· "noproxy => [0|1]"
Turn off the automatic call to the LWP::UserAgent "env_proxy"
function.
This needs to be explicitly turned off if you're using
Crypt::SSLeay to access a https site via a proxy server. Note: you
still need to set your HTTPS_PROXY environment variable as
appropriate.
· "onwarn => \&func"
Reference to a "warn"-compatible function, such as "Carp::carp",
that is called when a warning needs to be shown.
If this is set to "undef", no warnings will ever be shown.
However, it's probably better to use the "quiet" method to control
that behavior.
If this value is not passed, Mech uses "Carp::carp" if Carp is
installed, or "CORE::warn" if not.
· "onerror => \&func"
Reference to a "die"-compatible function, such as "Carp::croak",
that is called when there's a fatal error.
If this is set to "undef", no errors will ever be shown.
If this value is not passed, Mech uses "Carp::croak" if Carp is
installed, or "CORE::die" if not.
· "quiet => [0|1]"
Don't complain on warnings. Setting "quiet => 1" is the same as
calling "$mech->quiet(1)". Default is off.
· "stack_depth => $value"
Sets the depth of the page stack that keeps track of all the
downloaded pages. Default is effectively infinite stack size. If
the stack is eating up your memory, then set this to a smaller
number, say 5 or 10. Setting this to zero means Mech will keep no
history.
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:
· Windows IE 6
· Windows Mozilla
· Mac Safari
· Mac Mozilla
· Linux Mozilla
· Linux Konqueror
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()".
The current list is:
· Windows IE 6
· Windows Mozilla
· Mac Safari
· Mac Mozilla
· Linux Mozilla
· Linux Konqueror
known_agent_aliases()
Returns a list of all the agent aliases that Mech knows about.
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' => $tempfile );
and you can rest assured that the parms will get filtered down
appropriately.
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.
$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.
$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->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 nth item in history. The 0th item is the most recent
request and response, which would be acted on by methods like
"find_link()". The 1th item is the state you'd return to if you called
"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.
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 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():
$mech->content( format => 'text' )
Returns a text-only version of the page, with all HTML markup
stripped. This feature requires HTML::TreeBuilder to be installed, or
a fatal error will be thrown. This works only if the contents are
HTML.
$mech->content( base_href => [$base_href|undef] )
Returns the HTML document, modified to contain a "<base
href="$base_href">" mark-up in the header. $base_href is
"$mech->base()" if not specified. This is handy to pass the HTML to
e.g. HTML::Display. This works only if the contents are HTML.
$mech->content( raw => 1 )
Returns "$self->response()->content()", i.e. the raw contents from
the response.
$mech->content( decoded_by_headers => 1 )
Returns the content after applying all "Content-Encoding" headers but
with not additional mangling.
$mech->content( charset => $charset )
Returns "$self->response()->decoded_content(charset => $charset)"
(see HTTP::Response for details).
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.
$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 parms that "find_link()" uses.
Here some examples:
· 3rd link called "download"
$mech->follow_link( text => 'download', n => 3 );
· first link where the URL has "download" in it, regardless of case:
$mech->follow_link( url_regex => qr/download/i );
or
$mech->follow_link( url_regex => qr/(?i:download)/ );
· 3rd link on the page
$mech->follow_link( n => 3 );
· the link with the url
$mech->follow_link( url => '/other/page' );
or
$mech->follow_link( url => 'http://example.com/page' );
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.
$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()" 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()" method directly,
since it does the "get()" for you automatically.
Note that "<FRAME SRC="...">" tags are parsed out of the 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:
· "text => 'string'," and "text_regex => qr/regex/,"
"text" matches the text of the link against string, which must be
an exact match. To select a link with text that is exactly
"download", use
$mech->find_link( text => 'download' );
"text_regex" matches the text of the link against regex. To select
a link with text that has "download" anywhere in it, regardless of
case, use
$mech->find_link( text_regex => qr/download/i );
Note that the text extracted from the page's links are trimmed.
For example, "<a> foo </a>" is stored as 'foo', and searching for
leading or trailing spaces will fail.
· "url => 'string'," and "url_regex => qr/regex/,"
Matches the URL of the link against string or regex, as
appropriate. The URL may be a relative URL, like foo/bar.html,
depending on how it's coded on the page.
· "url_abs => string" and "url_abs_regex => regex"
Matches the absolute URL of the link against string or regex, as
appropriate. The URL will be an absolute URL, even if it's
relative in the page.
· "name => string" and "name_regex => regex"
Matches the name of the link against string or regex, as
appropriate.
· "id => string" and "id_regex => regex"
Matches the attribute 'id' of the link against string or regex, as
appropriate.
· "class => string" and "class_regex => regex"
Matches the attribute 'class' of the link against string or regex,
as appropriate.
· "tag => string" and "tag_regex => regex"
Matches the tag that the link came from against string or regex, as
appropriate. The "tag_regex" is probably most useful to check for
more than one tag, as in:
$mech->find_link( tag_regex => qr/^(a|frame)$/ );
The tags and attributes looked at are defined below, at
"$mech->find_link() : link format".
If "n" is not specified, it defaults to 1. Therefore, if you don't
specify any parms, 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".
The links come from the following:
"<a href=...>"
"<area href=...>"
"<frame src=...>"
"<iframe src=...>"
"<link href=...>"
"<meta content=...>"
$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()".
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
HTML::Form's "Input" section 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()" 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:
· "alt => 'string'" and "alt_regex => qr/regex/,"
"alt" matches the ALT attribute of the image against string, which
must be an exact match. To select a image with an ALT tag that is
exactly "download", use
$mech->find_image( alt => 'download' );
"alt_regex" matches the ALT attribute of the image against a
regular expression. To select an image with an ALT attribute that
has "download" anywhere in it, regardless of case, use
$mech->find_image( alt_regex => qr/download/i );
· "url => 'string'," and "url_regex => qr/regex/,"
Matches the URL of the image against string or regex, as
appropriate. The URL may be a relative URL, like foo/bar.html,
depending on how it's coded on the page.
· "url_abs => string" and "url_abs_regex => regex"
Matches the absolute URL of the image against string or regex, as
appropriate. The URL will be an absolute URL, even if it's
relative in the page.
· "tag => string" and "tag_regex => regex"
Matches the tag that the image came from against string or regex,
as appropriate. The "tag_regex" is probably most useful to check
for more than one tag, as in:
$mech->find_image( tag_regex => qr/^(img|input)$/ );
The tags supported are "<img>" and "<input>".
If "n" is not specified, it defaults to 1. Therefore, if you don't
specify any parms, 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:
$mech->find_image( image => 'News', url_regex => qr/cnn\.com/ );
The return value is a reference to an array containing a
WWW::Mechanize::Image object for every image in "$self->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()". 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 numberth form on the page as the target for subsequent
calls to "field()" and "click()". 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()" and
"click()".
Emits a warning and returns undef if no form is found.
The first form is number 1, not zero.
$mech->form_name( $name )
Selects a form by name. If 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()" and
"click()".
Returns undef if no form is found.
$mech->form_id( $name )
Selects a form by ID. If 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()" and
"click()".
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 )
Selects a form by passing in a list of field names it must contain. If
there is more than one form on the page with that matches, 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()"
and "click()".
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. (Currently does not work for attribute "action" due to
implementation details of HTML::Form.) When given more than one pair,
all criteria must match. Using "undef" as value means that the
attribute in question may not be present.
All matching forms (perhaps none) are returned as a list of HTML::Form
objects.
$mech->form_with( $attr1 => $value1, $attr2 => $value2, ... )
Searches for forms with arbitrary attribute/value pairs within the
<form> tag. (Currently does not work for attribute "action" due to
implementation details of HTML::Form.) When given more than one pair,
all criteria must match. Using "undef" as value means that the
attribute in question may not be present.
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()"
and "click()".
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 )
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()" or
"form_number()" method or defaulting to the first form on the page).
The optional $number parameter is used to distinguish between two
fields with the same name. The fields are numbered from 1.
$mech->select($name, $value)
$mech->select($name, \@values)
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. [Note: the documentation
previously claimed that only the last value would be set, but this was
incorrect.] 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->set_fields( $name => $value ... )
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 foo field
$mech->set_fields( $name => [ 'foo', 2 ] );
The fields are numbered from 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. 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.
$mech->untick($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 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.
· "name => name"
Clicks the button named name in the current form.
· "id => id"
Clicks the button with the id id in the current form.
· "number => n"
Clicks the nth button in the current form. Numbering starts at 1.
· "value => value"
Clicks the button with the value value in the current form.
· "input => $inputobject"
Clicks on the button referenced by $inputobject, an instance of
HTML::Form::SubmitInput obtained e.g. from
$mech->current_form()->find_input( undef, 'submit' )
$inputobject must belong to the current form.
· "x => x"
· "y => y"
These arguments (optional) allow you to specify the (x,y)
coordinates of the click.
$mech->submit()
Submits the current form, without specifying a button to click.
Actually, no button is clicked at all.
Returns an HTTP::Response object.
This used to be a synonym for "$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.
· "fields => \%fields"
Specifies the fields to be filled in the current form.
· "with_fields => \%fields"
Probably all you need for the common case. It combines a smart form
selector and data setting in one operation. It selects the first
form that contains all fields mentioned in "\%fields". This is
nice because you don't need to know the name or number of the form
to do this.
(calls "form_with_fields()" and "set_fields()").
If you choose this, the form_number, form_name, form_id and fields
options will be ignored.
· "form_number => n"
Selects the nth form (calls "form_number()"). If this parm is not
specified, the currently-selected form is used.
· "form_name => name"
Selects the form named name (calls "form_name()")
· "form_id => ID"
Selects the form with ID ID (calls "form_id()")
· "button => button"
Clicks on button button (calls "click()")
· "x => x, y => y"
Sets the x or y values for "click()"
· "strict_forms => bool"
Sets the HTML::Form strict flag which causes form submission to
croak if any of the passed fields don't exist on the page, and/or a
value doesn't exist in a select element. By default HTML::Form
defaults this value to false.
If no form is selected, the first form found is used.
If button is not passed, then the "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->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" 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->save_content( $filename, binary => 1 )
Filehandle is set with "binmode" to ":raw" and contents are taken
calling "$self->content(decoded_by_headers => 1)". Same as calling:
$mech->save_content( $filename, binmode => ':raw',
decoded_by_headers => 1 );
This should be the safest way to save contents verbatim.
$mech->save_content( $filename, binmode => $binmode )
Filehandle is set to binary mode. If $binmode begins with ':', it
is passed as a parameter to "binmode":
binmode $fh, $binmode;
otherwise the filehandle is set to binary mode if $binmode is true:
binmode $fh;
all other arguments
are passed as-is to "$mech->content(%opts)". In particular,
"decoded_by_headers" might come handy if you want to revert the
effect of line compression performed by the web server but without
further interpreting the contents (e.g. decoding it according to
the charset).
$mech->dump_headers( [$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.
$mech->dump_forms( [$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.
$mech->dump_text( [$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( $html );
This method is also used internally by the mech itself to update its
own HTML content when loading a page. This means that if you would like
to systematically perform the above HTML substitution, you would
overload update_html in a subclass thusly:
package MyMech;
use base 'WWW::Mechanize';
sub update_html {
my ($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".
Overloading this method is also the recommended way of implementing
extra validation steps (e.g. link checkers) for every HTML page
received. "warn" and "die" 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->post()
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") 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.
WWW::MECHANIZE'S GIT REPOSITORYWWW::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:
#21 WWW::Mechanize 101
#22 Scraping with WWW::Mechanize
#36 Downloading Images from Webshots
#44 Archiving Yahoo! Groups Messages with WWW::Yahoo::Groups
#64 Super Author Searching
#73 Scraping TV Listings
The book was also positively reviewed on Slashdot:
<http://books.slashdot.org/article.pl?sid=03/12/11/2126256>
ONLINE RESOURCES AND SUPPORT
· WWW::Mechanize mailing list
The Mech mailing list is at
<http://groups.google.com/group/www-mechanize-users> and is
specific to Mechanize, unlike the LWP mailing list below. Although
it is a users list, all development discussion takes place here,
too.
· LWP mailing list
The LWP mailing list is at
<http://lists.perl.org/showlist.cgi?name=libwww>, and is more user-
oriented and well-populated than the WWW::Mechanize list.
· Perlmonks
<http://perlmonks.org> is an excellent community of support, and
many questions about Mech have already been answered there.
· WWW::Mechanize::Examples
A random array of examples submitted by users, included with the
Mechanize distribution.
ARTICLES ABOUT WWW::MECHANIZE
· <http://www.ibm.com/developerworks/linux/library/wa-perlsecure/>
IBM article "Secure Web site access with Perl"
· <http://www.oreilly.com/catalog/googlehks2/chapter/hack84.pdf>
Leland Johnson's hack #84 in Google Hacks, 2nd Edition is an
example of a production script that uses WWW::Mechanize and
HTML::TableContentParser. It takes in keywords and returns the
estimated price of these keywords on Google's AdWords program.
· <http://www.perl.com/pub/a/2004/06/04/recorder.html>
Linda Julien writes about using HTTP::Recorder to create
WWW::Mechanize scripts.
· <http://www.developer.com/lang/other/article.php/3454041>
Jason Gilmore's article on using WWW::Mechanize for scraping sales
information from Amazon and eBay.
· <http://www.perl.com/pub/a/2003/01/22/mechanize.html>
Chris Ball's article about using WWW::Mechanize for scraping TV
listings.
· <http://www.stonehenge.com/merlyn/LinuxMag/col47.html>
Randal Schwartz's article on scraping Yahoo News for images. It's
already out of date: He manually walks the list of links hunting
for matches, which wouldn't have been necessary if the
"find_link()" method existed at press time.
· <http://www.perladvent.org/2002/16th/>
WWW::Mechanize on the Perl Advent Calendar, by Mark Fowler.
· <http://www.linux-magazin.de/Ausgaben/2004/03/Datenruessel/%28language%29/ger-DE>
Michael Schilli's article on Mech and WWW::Mechanize::Shell for the
German magazine Linux Magazin.
Other modules that use Mechanize
Here are modules that use or subclass Mechanize. Let me know of any
others:
· Finance::Bank::LloydsTSB
· HTTP::Recorder
Acts as a proxy for web interaction, and then generates
WWW::Mechanize scripts.
· Win32::IE::Mechanize
Just like Mech, but using Microsoft Internet Explorer to do the
work.
· WWW::Bugzilla
· WWW::CheckSite
· WWW::Google::Groups
· WWW::Hotmail
· WWW::Mechanize::Cached
· WWW::Mechanize::Cached::GZip
· WWW::Mechanize::FormFiller
· WWW::Mechanize::Shell
· WWW::Mechanize::Sleepy
· WWW::Mechanize::SpamCop
· WWW::Mechanize::Timed
· WWW::SourceForge
· WWW::Yahoo::Groups
· WWW::Scripter
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, Phillipe 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) 2004-2016 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.
perl v5.26.0 2017-09-24 WWW::Mechanize(3pm)
