/ 
WWW-Scripter-0.003
River stage one • 4 direct dependents • 4 total dependents
/ WWW::Scripter

NAME

WWW::Scripter - For scripting web sites that have scripts

VERSION

0.003 (alpha)

SYNOPSIS

use WWW::Scripter;
$w = new WWW::Scripter;

$w->use_plugin('Ajax');  # packaged separately

$w->get('http://some.site.com/that/relies/on/ajax');
$w->eval(' alert("Hello from JavaScript") ');
$w->document->getElementsByTagName('div')->[0]->....

$w->content; # returns the HTML content, possibly modified
             # by scripts

DESCRIPTION

This is a subclass of WWW::Mechanize that uses the W3C DOM and provides support for scripting.

No actual scripting engines are provided with WWW::Scripter, but are available as separate plugins. (See also the "SEE ALSO" section below.)

INTERFACE

See WWW::Mechanize for a vast list of methods that this module inherits.

In addition to those, this module implements the well-known Window interface, providing also a few routines for attaching scripting engines and what-not.

In the descriptions below, $w refers to the WWW::Scripter object. You can think of it as short for either 'WWW::Scripter' or 'window'.

Constructor

my $w = new WWW::Scripter @args

See WWW::Mechanize and LWP::UserAgent for details on what arguments the constructor accepts.

The Window Interface

In addition to the methods listed here, see also HTML::DOM::View and HTML::DOM::EventTarget.

location

Returns the location object (see WWW::Scripter::Location). If you pass an argument, it sets the href attribute of the location object.

alert
confirm
prompt

Each of these calls the function assigned by one of the set_* methods below under "Window-Related Methods".

Returns the navigator object. This currently has three properties, appName (set to ref $w) appVersion (ref($w)->VERSION) and userAgent (same as $w->agent).

You can pass values to appName and appVersion to set them.

setTimeout ( $code, $ms );

This schedules the $code to run after $ms seconds have elapsed, returning a number uniquely identifying the time-out.

clearTimeout ( $timeout_id )

The cancels the time-out corresponding to the $timeout_id.

open ( $url )

This is a temporary placeholder. Right now it ignores all its args except the first, and goes to the given URL, such that ->open(foo) is equivalent to ->location('foo').

history

Returns the history object. See WWW::Scripter::History.

window
self

These two return the window object itself.

frames

Although the W3C DOM specifies that this return $w (the window itself), for efficiency's sake this returns a separate object which one can use as a hash or array reference to access its sub-frames. (The window object itself cannot be used that way.) The frames object (class WWW::Scripter::Frames) also has a window method that returns $w.

In list context a list of frames is returned.

length

Returns the number of frames. $w->length is equivalent to scalar @{$w->frames}.

top

Returns the 'top' window, which is the window itself if there are no frames.

parent

Returns the parent frame, if there is one, or the window object itself otherwise.

These methods are not part of the Window interface, but are closely related to the object's window behaviour.

set_alert_function
set_confirm_function
set_prompt_function

Use these to set the functions called by the above methods. There are no default confirm and prompt functions. The default alert prints to the currently selected file handle, with a line break tacked on the end.

check_timers

This evaluates the code associated with each timeout registered with the setTimeout method, if the appropriate interval has elapsed.

count_timers

This returns the number of timers currently registered.

Methods for Plugins, Scripting, etc.

eval ( $code [, $scripting_language] )

Evaluates the $code passed to it. This method dies if there is no script handler registered for the $scripting_language.

use_plugin ( $plugin_name [, @options] )

This will automatically require() the plugin for you, and then initialise it. To pass extra options to the plugin after loading it, just use the same syntax again. This will return the plugin object if the plugin has one.

plugin ( $plugin_name )

This will return the plugin object, if it has one. Some plugins may provide this as a way to communicate directly with the plugin.

You can also use the return value as a boolean, to see whether a plugin is loaded.

scripts_enabled ( $new_val )

This returns a boolean indicating whether scripts are enabled. It is true by default. You can disable scripts by passing a false value. When you disable scripts, event handlers are also disabled, as is the registration of event handlers by HTML event attributes.

script_handler ( $language_re, $object )

A script handler is a special object that knows how to run scripts in a particular language. Use this method to register such an object.

$language_re is a regular expression that will be matched against a scripting language name (from a 'language' HTML attribute) or MIME type (<script type=...). You can also use the special value 'default'.

$object is the script handler object. For its interface, see "SCRIPT HANDLERS", below.

class_info ( \%interfaces )

With this you can provide information for Perl classes to scripting languages, so that scripts can handle objects of those classes.

You should pass a hash ref that has the structure described in HTML::DOM::Interface, except that this method also accepts a _constructor hash element, which should be set to the name of the method to be called when the constructor function is called from the scripting language (e.g., _constructor => 'new') or a subroutine reference.

The return value is a list of all hashrefs passed to class_info so far plus a few that WWW::Scripter has by default (to support the DOM). You can call it without any arguments just to get that list.

Other Methods

forward

The equivalent of hitting the 'forward' button in a browser. This, of course, only works after back.

clear_history ( $including_current_page )

This clears the history, preventing back from working until after the next request, and freeing up some memory. If supplied with a true argument, it also clears the current page. It returns $w.

THE %WindowInterface HASH

The hash named %WWW::Scripter::WindowInterface lists the interface members for the window object. It follows the same format as hashes within %HTML::DOM::Interface, like this:

(
    alert => VOID|METHOD,
    confirm => BOOL|METHOD,
    ...
)

It only includes those methods listed above under "The Window Interface".

SCRIPT HANDLERS

This section is only of interest to those implementing scripting engines. If you are not writing one, skip this section (or just read it anyway).

A script handler object must provide the following methods:

eval ( $w, $code, $url, $line, $is_inline )

(where $w is the WWW::Scripter object)

This is supposed to run the $code passed to it.

event2sub ( $w, $elem, $event_name, $code, $url, $line )

This is called for each HTML event attribute (onclick, etc.). It should return a coderef that runs the $code.

WRITING PLUGINS

Plugins are usually under the WWW::Scripter::Plugin:: namespace. If a plugin name has a hyphen (-) in it, the module name will contain a double colon (::). If, when you pass a plugin name to use_plugin or plugin, it has a double colon in its name, it will be treated as a fully-qualified module name (possibly) outside the usual plugin namespace. Here are some examples:

Plugin Name       Module Name
-----------       -----------
Chef              WWW::Scripter::Plugin::Chef
Man-Page          WWW::Scripter::Plugin::Man::Page
My::Odd::Plugin   My::Odd::Plugin

This module will need to have an init method, and possibly two more named options and clone, respectively:

init

init will be called as a class method the first time use_plugin is called for a particular plugin. The second argument ($_[1]) will be the WWW::Scripter object. The third argument will be an array ref of options (see "options", below).

It may return an object if the plugin has one.

options

When $w->use_plugin is called, if there are any arguments after the plugin name, then the plugin object's options method will be called with the options themselves as the arguments.

If a plugin does not provide an object, an error will be thrown if options are passed to use_plugin.

The init method can override this, however. When it is called, its its third argument is a reference to an array containing the options passed to use_plugin. The contents of that same array will be used when options is called, so init can modify it and even prevent options from being called altogether, by emptying the array.

clone

When the WWW::Scripter object is cloned (via the clone method), every plugin that has a clone method (as determined by ->can('clone')), will also be cloned. The new clone of the WWW::Scripter object is passed as its argument.

If the plugin needs to record data pertinent to the current page, it can do so by associating them with the document or the request via a field hash. See Hash::Util::FieldHash and Hash::Util::FieldHash::Compat.

Handlers

See LWP's Handlers feature.

From within LWP's request_* and response_* handlers, you can call WWW::Scripter::abort to abort the request and prevent a new entry from being created in browser history via _push_page_stack.

WWW::Scripter will export this function upon request:

use WWW::Scripter qw[ abort ];

or you can call it with a fully qualified name:

WWW::Scripter::abort();

BUGS

This is still an unfinished work. There are probably scores of bugs crawling all over the place. Here are some that are known (apart from the fact that so many features are still missing):

  • Mech's stack_depth option is not honoured.

  • When no browsing has happened, the current page is supposed to be about:blank. This is not yet the case.

  • URL fragments are not supported properly yet. (A link to a fragment on the current page is not supposed to reload it, but it does.)

  • reload does not replace the response object with a new one. This causes problems for plugins that identify the page by response object.

PREREQUISITES

perl 5.8.3 or higher (5.8.4 or higher recommended)

Hash::Util::FieldHash::Compat

HTML::DOM 0.021 or higher

LWP

URI

WWW::Mechanize

AUTHOR & COPYRIGHT

Copyright (C) 2009, Father Chrysostomos (sprout at, um, cpan dot org)

This program is free software; you may redistribute or modify it (or both) under the same terms as perl.

CONFESSION

Some of the code in here was stolen from the immediate superclass, WWW::Mechanize, as were some of the tests and test data.

SEE ALSO

WWW::Scripter sub-modules: ::Location and ::History.

See WWW::Mechanize, of which this is a subclass.

See also the following plugins:

WWW::Scripter::Plugin::JavaScript
WWW::Scripter::Plugin::Ajax

And, if you are curious, have a look at the plugin version of WWW::Mechanize and WWW::Mechanize::Plugin::DOM (experimental and now deprecated) that this was originally based on: http://www-mechanize.googlecode.com/svn/wm/branches/plugins/

1 POD Error

The following errors were encountered while parsing the POD:

Around line 279:

You forgot a '=back' before '=head1'