libscrappy-perl/README

NAME
    Scrappy - The All Powerful Web Spidering, Scraping, Creeping Crawling
    Framework

VERSION
    version 0.94112090

SYNOPSIS
        #!/usr/bin/perl
        use Scrappy;

        my  $scraper = Scrappy->new;
        
        $scraper->crawl('http://search.cpan.org/recent',
                '/recent' => {
                    '#cpansearch li a' => sub {
                        print $_[1]->{href}, "\n";
                    }
                }
            );

    And now manually, ... without crawl, the above is similar to the
    following ...

        #!/usr/bin/perl
        use Scrappy;

        my  $scraper = Scrappy->new;
            
        if ($scraper->get($url)->page_loaded) {
                $scraper->select('#cpansearch li a')->each(sub{
                    print shift->{href}, "\n";
                });
            }

DESCRIPTION
    Scrappy is an easy (and hopefully fun) way of scraping, spidering,
    and/or harvesting information from web pages, web services, and more.
    Scrappy is a feature rich, flexible, intelligent web automation tool.

    Scrappy (pronounced Scrap+Pee) == 'Scraper Happy' or 'Happy Scraper'; If
    you like you may call it Scrapy (pronounced Scrape+Pee) although Python
    has a web scraping framework by that name and this module is not a port
    of that one.

  FEATURES
    Scrappy provides a framework containing all the tools neccessary to
    create a simple yet powerful web scraper. At its core, Scrappy loads an
    array of features for access control, event logging, session handling,
    url matching, web request and response handling, proxy management, web
    scraping, and downloading.

    Futhermore, Scrappy provides a simple Moose-based plugin system that
    allows Scrappy to be easily extended.

        my  $scraper = Scrappy->new;
        
        $scraper->control;      # Scrappy::Scraper::Control (access control)
            $scraper->parser;       # Scrappy::Scraper::Parser (web scraper)
            $scraper->user_agent;   # Scrappy::Scraper::UserAgent (user-agent tools)
            $scraper->logger;       # Scrappy::Logger (event logger)
            $scraper->queue;        # Scrappy::Queue (flow control for loops)
            $scraper->session;      # Scrappy::Session (session management)

    Please see the METHODS section for a more in-depth look at all Scrappy
    functionality.

  ATTRIBUTES
    The following is a list of object attributes available with every
    Scrappy instance, attributes always return an instance of the class they
    represent.

   content
    The content attribute holds the HTTP::Response object of the current
    request. Returns undef if no page has been successfully fetched.

        my  $scraper = Scrappy->new;
            $scraper->content;

   control
    The control attribute holds the Scrappy::Scraper::Control object which
    is used the provide access conrtol to the scraper.

        my  $scraper = Scrappy->new;
            $scraper->control;
            
        ... $scraper->control->restrict('google.com');
            ... $scraper->control->allow('cpan.org');
            ... if $scraper->control->is_allowed($url);

   debug
    The debug attribute holds a boolean which controls whether event logs
    are captured.

        my  $scraper = Scrappy->new;
            $scraper->debug(1);

   logger
    The logger attribute holds the Scrappy::Logger object which is used to
    provide event logging capabilities to the scraper.

        my  $scraper = Scrappy->new;
            $scraper->logger;

   parser
    The parser attribute holds the Scrappy::Scraper::Parser object which is
    used to scrape html data from the specified source material.

        my  $scraper = Scrappy->new;
            $scraper->parser;

   plugins
    The plugins attribute holds the Scrappy::Plugin object which is an
    interface used to load plugins.

        my  $scraper = Scrappy->new;
            $scraper->plugins;

   queue
    The queue attribute holds the Scrappy::Queue object which is used to
    provide flow-control for the standard loop approach to crawling.

        my  $scraper = Scrappy->new;
            $scraper->queue;

   session
    The session attribute holds the Scrappy::Session object which is used to
    provide session support and persistent data across executions.

        my  $scraper = Scrappy->new;
            $scraper->session;

   user_agent
    The user_agent attribute holds the Scrappy::Scraper::UserAgent object
    which is used to set and manipulate the user-agent header of the
    scraper.

        my  $scraper = Scrappy->new;
            $scraper->user_agent;

   worker
    The worker attribute holds the WWW::Mechanize object which is used
    navigate web pages and provide request and response header information.

        my  $scraper = Scrappy->new;
            $scraper->worker;

METHODS
  back
    The back method is the equivalent of hitting the "back" button in a
    browser, it returns the previous page (response) and returns that URL,
    it will not backtrack beyond the first request.

        my  $scraper = Scrappy->new;
            
        $scraper->get(...);
            ...
            $scraper->get(...);
            ...
            my $last_url = $scraper->back;

  cookies
    The cookies method returns an HTTP::Cookie object. Note! Cookies can be
    made persistent by enabling session-support. Session-support is enable
    by simply specifying a file to be used.

        my  $scraper = Scrappy->new;
        
        $scraper->session->write('session.yml'); # enable session support
            $scraper->get(...);
        my  $cookies = $scraper->cookies;

  crawl
    The crawl method is very useful when it is desired to crawl an entire
    website or at-least partially, it automates the tasks of creating a
    queue, fetching and parsing html pages, and establishing simple
    flow-control. See the SYNOPSIS for a simplified example, ... the
    following is a more complex example.

        my  $scrappy = Scrappy->new;
        
        $scrappy->crawl('http://search.cpan.org/recent',
                '/recent' => {
                    '#cpansearch li a' => sub {
                        my ($self, $item) = @_;
                        # follow all recent modules from search.cpan.org
                        $self->queue->add($item->{href});
                    }
                },
                '/~:author/:name-:version/' => {
                    'body' => sub {
                        my ($self, $item, $args) = @_;
                        
                    my $reviews = $self
                        ->select('.box table tr')->focus(3)->select('td.cell small a')
                        ->data->[0]->{text};
                        
                    $reviews = $reviews =~ /\d+ Reviews/ ?
                            $reviews : '0 reviews';
                        
                    print "found $args->{name} version $args->{version} ".
                            "[$reviews] by $args->{author}\n";
                    }
                }
            );

  domain
    The domain method returns the domain host of the current page. Local
    pages, e.g. file:///this/that/the_other will return undef.

        my  $scraper = Scrappy->new;
        
        $scraper->get('http://www.google.com');
            print $scraper->domain; # print www.google.com

  download
    The download method is passed a URL, a Download Directory Path and a
    optionally a File Path, then it will follow the link and store the
    response contents into the specified file without leaving the current
    page. Basically it downloads the contents of the request (especially
    when the request pushes a file download). If a File Path is not
    specified, Scrappy will attempt to name the file automatically resorting
    to a random 6-charater string only if all else fails, then returns to
    the originating page.

        my  $scaper = Scrappy->new;
        my  $requested_url = '...';
        
        $scraper->download($requested_url, '/tmp');
        
        # supply your own file name
            $scraper->download($requested_url, '/tmp', 'somefile.txt');

  dumper
    The dumper method is a convenience feature that passes the passed-in
    objects to Data::Dumper which in turn returns a stringified
    representation of that object/data-structure.

        my  $scaper = Scrappy->new;
        my  $requested_url = '...';
        
        $scraper->get($requested_url);
        
    my  $data = $scraper->select('//a[@href]')->data;
        
    # print out the scraped data
        print $scraper->dumper($data);

  form
    The form method is used to submit a form on the current page.

        my  $scraper = Scrappy->new;
        
        $scraper->form(fields => {
                username => 'mrmagoo',
                password => 'foobarbaz'
            });
            
        # or more specifically, for pages with multiple forms
            
        $scraper->form(form_name => 'login_form', fields => {
                username => 'mrmagoo',
                password => 'foobarbaz'
            });
            
        $scraper->form(form_number => 1, fields => {
                username => 'mrmagoo',
                password => 'foobarbaz'
            });

  get
    The get method takes a URL or URI object, fetches a web page and returns
    the Scrappy object.

        my  $scraper = Scrappy->new;
        
    if ($scraper->get($new_url)->page_loaded) {
            ...
        }
        
    # $self->content has the HTTP::Response object

  log
    The log method logs an event with the event logger.

        my  $scraper = Scrappy->new;
            
        $scraper->debug(1); # unneccessary, on by default
            $scraper->logger->verbose(1); # more detailed log
            
        $scraper->log('error', 'Somthing bad happened');
            
        ...
            
        $scraper->log('info', 'Somthing happened');
            $scraper->log('warn', 'Somthing strange happened');
            $scraper->log('coolness', 'Somthing cool happened');

    Note! Event logs are always recorded but never automatically written to
    a file unless explicitly told to do so using the following:

            $scraper->logger->write('log.yml');

  page_content_type
    The page_content_type method returns the content_type of the current
    page.

        my  $scraper = Scrappy->new;
            $scraper->get('http://www.google.com/');
            print $scraper->page_content_type; # prints text/html

  page_data
    The page_data method returns the HTML content of the current page,
    additionally this method when passed a string with HTML markup, updates
    the content of the current page with that data and returns the modified
    content.

        my  $scraper = Scrappy->new;
            $scraper->get(...);
        my  $html = $scraper->page_data;

  page_ishtml
    The page_ishtml method returns true/false based on whether our content
    is HTML, according to the HTTP headers.

        my $scraper = Scrappy->new;
        
        $scraper->get($requested_url);
            if ($scraper->is_html) {
                ...
            }

  page_loaded
    The page_loaded method returns true/false based on whether the last
    request was successful.

        my $scraper = Scrappy->new;
        
        $scraper->get($requested_url);
            if ($scraper->page_loaded) {
                ...
            }

  page_match
    The page_match method checks the passed-in URL (or URL of the current
    page if left empty) against the URL pattern (route) defined. If URL is a
    match, it will return the parameters of that match much in the same way
    a modern web application framework processes URL routes.

        my $url = 'http://somesite.com/tags/awesomeness';
        
    ...
        
    my $scraper = Scrappy->new;
        
    # match against the current page
        my $this = $scraper->page_match('/tags/:tag');
        if ($this) {
            print $this->{'tag'};
            # ... prints awesomeness
        }
        
    .. or ..
        
    # match against a passed url
        my $this = $scraper->page_match('/tags/:tag', $url, {
            host => 'somesite.com'
        });
        
    if ($this) {
            print "This is the ", $this->{tag}, " page";
            # ... prints this is the awesomeness page
        }

  page_reload
    The page_reload method acts like the refresh button in a browser, it
    simply repeats the current request.

        my  $scraper = Scrappy->new;
            
        $scraper->get(...);
            ...
            $scraper->reload;

  page_status
    The page_status method returns the 3-digit HTTP status code of the
    response.

        my  $scraper = Scrappy->new;
            $scraper->get(...);
            
        if ($scraper->page_status == 200) {
                ...
            }

  page_text
    The page_text method returns a text representation of the last page
    having all HTML markup stripped.

        my  $scraper = Scrappy->new;
            $scraper->get(...);
            
    my  $text = $scraper->page_text;

  page_title
    The page_title method returns the content of the title tag if the
    current page is HTML, otherwise returns undef.

        my  $scraper = Scrappy->new;
            $scraper->get('http://www.google.com/');
            
    my  $title = $scraper->page_title;
            print $title; # print Google

  pause
    This method sets breaks between your requests in an attempt to simulate
    human interaction.

        my  $scraper = Scrappy->new;
            $scraper->pause(20);
        
        $scraper->get($request_1);
            $scraper->get($request_2);
            $scraper->get($request_3);

    Given the above example, there will be a 20 sencond break between each
    request made, get, post, request, etc., You can also specify a range to
    have the pause method select from at random...

            $scraper->pause(5,20);
        
        $scraper->get($request_1);
            $scraper->get($request_2);
        
        # reset/turn it off
            $scraper->pause(0);
        
        print "I slept for ", ($scraper->pause), " seconds";

    Note! The download method is exempt from any automatic pausing.

  plugin
    The plugin method allow you to load a plugin. Using the appropriate case
    is recommended but not neccessary. See Scrappy::Plugin for more
    information.

        my $scraper = Scrappy->new;
        
    $scraper->plugin('foo_bar');    # will load Scrappy::Plugin::FooBar
        $scraper->plugin('foo-bar');    # will load Scrappy::Plugin::Foo::Bar
        $scraper->plugin('Foo::Bar');   # will load Scrappy::Plugin::Foo::Bar
        
    # more pratically
        $scraper->plugin('whois', 'spammer_check');
        
    ... somewhere in code
        
    my $var = $scraper->plugin_method();

        # example using core plugin Scrappy::Plugin::RandomProxy
        
    my  $s = Scrappy->new;
            
        $s->plugin('random_proxy');
            $s->use_random_proxy;
            
        $s->get(...);

  post
    The post method takes a URL, a hashref of key/value pairs, and
    optionally an array of key/value pairs, and posts that data to the
    specified URL, then returns an HTTP::Response object.

        my $scraper = Scrappy->new;

        $scraper->post($requested_url, {
            input_a => 'value_a',
            input_b => 'value_b'
        });
        
    # w/additional headers
        my %headers = ('Content-Type' => 'multipart/form-data');
        $scraper->post($requested_url, {
            input_a => 'value_a',
            input_b => 'value_b'
        },  %headers);

    Note! The most common post headers for content-type are
    application/x-www-form-urlencoded and multipart/form-data.

  proxy
    The proxy method will set the proxy for the next request to be tunneled
    through.

        my $scraper = Scrappy->new;
        
    $scraper->proxy('http', 'http://proxy1.example.com:8000/');
        $scraper->get($requested_url);
        
    $scraper->proxy('http', 'ftp', 'http://proxy2.example.com:8000/');
        $scraper->get($requested_url);
        
    # best practice when using proxies
        
    use Tiny::Try;
        
    my $proxie = Scrappy->new;
        
    $proxie->proxy('http', 'http://proxy.example.com:8000/');
        
    try {
            $proxie->get($requested_url);
        } catch {
            die "Proxy failed\n";
        };

    Note! When using a proxy to perform requests, be aware that if they fail
    your program will die unless you wrap your code in an eval statement or
    use a try/catch mechanism. In the example above we use Tiny::Try to trap
    any errors that might occur when using proxy.

  request_denied
    The request_denied method is a simple shortcut to determine if the page
    you requested got loaded or redirected. This method is very useful on
    systems that require authentication and redirect if not authorized. This
    function return boolean, 1 if the current page doesn't match the
    requested page.

        my $scraper = Scrappy->new;
        $scraper->get($url_to_dashboard);
        
    if ($scraper->request_denied) {
            # do login, again
        }
        else {
            # resume ...
        }

  response
    The response method returns the HTTP::Repsonse object of the current
    page.

        my  $scraper = Scrappy->new;
            $scraper->get(...);
        my  $res = $scraper->response;

  select
    The select method takes XPATH or CSS selectors and returns a
    Scrappy::Scraper::Parser object which contains the matching elements.

        my $scraper = Scrappy->new;
        
    # return a list of links
        my $list = $scraper->select('#profile li a')->data; # see Scrappy::Scraper::Parser
        
    foreach my $link (@{$list}) {
            print $link->{href}, "\n";
        }
        
    # Zoom in on specific chunks of html code using the following ...
        my $list = $scraper
        ->select('#container table tr') # select all rows
        ->focus(4) # focus on the 5th row
        ->select('div div')->data;
        
    # The code above selects the div > div inside of the 5th tr in #container table
        # Access attributes html, text and other attributes as follows...
        
    $element = $scraper->select('table')->data->[0];
        $element->{html}; # HTML representation of the table
        $element->{text}; # Table stripped of all HTML
        $element->{cellpadding}; # cellpadding
        $element->{height}; # ...

  stash
    The stash method sets a stash (shared) variable or returns a reference
    to the entire stash object.

        my  $scraper = Scrappy->new;
            $scraper->stash(age => 31);
            
        print 'stash access works'
                if $scraper->stash('age') == $scraper->stash->{age};
        
    my  @array = (1..20);
            $scraper->stash(integers => [@array]);

  store
    The store method stores the contents of the current page into the
    specified file. If the content-type does not begin with 'text', the
    content is saved as binary data.

        my  $scraper = Scrappy->new;
        
        $scraper->get($requested_url);
            $scraper->store('/tmp/foo.html');

  url
    The url method returns the complete URL for the current page.

        my  $scraper = Scrappy->new;
            $scraper->get('http://www.google.com/');
            print $scraper->url; # prints http://www.google.com/

AUTHOR
    Al Newkirk <awncorp@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2010 by awncorp.

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