Skip to content

st3vil/pquery-pm

 
 

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

21 Commits
 
 
 
 
 
 
 
 
 
 

Repository files navigation

NAME
    pQuery - A port of jQuery.js to Perl

SYNOPSIS
        use pQuery;

        pQuery("http://google.com/search?q=pquery")
            ->find("h2")
            ->each(sub {
                my $i = shift;
                print $i + 1, ") ", pQuery($_)->text, "\n";
            });

DESCRIPTION
    pQuery is a pragmatic attempt to port the jQuery JavaScript framework to
    Perl. It is pragmatic in the sense that it switches certain JavaScript
    idioms for Perl ones, in order to make the use of it concise. A primary
    goal of jQuery is to "Find things and do things, concisely". pQuery has
    the same goal.

    pQuery exports a single function called "pQuery". (Actually, it also
    exports the special "PQUERY" function. Read below.) This function acts a
    constructor and does different things depending on the arguments you
    give it. This is discussed in the CONSTRUCTORS section below.

    A pQuery object acts like an array reference (because, in fact, it is).
    Typically it is an array of pQuery::DOM elements, but it can be an array
    of anything.

    pQuery::DOM is roughly an attempt to duplicate JavaScript's DOM in Perl.
    It subclasses HTML::TreeBuilder/HTML::Element so there are a few
    differences to be aware of. See the pQuery::DOM documentation for
    details.

    Like jQuery, pQuery methods return a pQuery object; either the original
    object or a new derived object. All pQuery METHODS are described below.

THE ROYAL PQUERY
    The power of jQuery is that single method calls can apply to many DOM
    objects. pQuery does the exact same thing but can take this one step
    further. A single PQUERY object can contain several DOMs!

    Consider this example:

        > perl -MpQuery -le 'PQUERY(\
            map "http://search.cpan.org/~$_/", qw(ingy gugod miyagawa))\
            ->find("table")->eq(1)->find("tr")\
            ->EACH(sub{\
                printf("%40s - %s Perl distributions\n", $_->url, $_->length - 1)\
            })'
                   http://search.cpan.org/~ingy/ - 88 Perl distributions
                  http://search.cpan.org/~gugod/ - 86 Perl distributions
               http://search.cpan.org/~miyagawa/ - 138 Perl distributions

    The power lies in "PQUERY", a special constructor that creates a wrapper
    object for many pQuery objects, and applies all methods called on it to
    all the pQuery objects it contains.

CONSTRUCTORS
    The pQuery constructor is an exported function called "pQuery". It does
    different things depending on the arguments you pass it.

  URL
    If you pass pQuery a URL, it will attempt to get the page and use its
    HTML to create a pQuery::DOM object. The pQuery object will contain the
    top level pQuery::DOM object.

        pQuery("http://google.com");

    It will also set the global variable $pQuery::document to the resulting
    DOM object. Future calls to pQuery methods will use this document if
    none other is supplied.

  HTML
    If you already have an HTML string, pass it to pQuery and it will create
    a pQuery::DOM object. The pQuery object will contain the top level
    pQuery::DOM object.

        pQuery("<p>Hello <b>world</b>.</p>");

  FILE
    If you pass pQuery a string that ends with .html and contains no
    whitespace, pQuery will assume it is the name of a file containing html
    and will read the contents and parse the HTML into a new DOM.

        pQuery("my/webpage.html");

  Selector String
    You can create a pQuery object with a selector string just like in
    jQuery. The problem is that Perl doesn't have a global document object
    lying around like JavaScript does.

    One thing you can do is set the global variable, $pQuery::document, to a
    pQuery::DOM document. This will be used by future selectors.

    Another thing you can do is pass the document to select on as the second
    parameter. (jQuery also has this second, context parameter).

        pQuery("table.mygrid > td:eq(7)", $dom);

  pQuery Object
    You can create a new pQuery object from another pQuery object. The new
    object will be a shallow copy.

        my $pquery2 = pQuery($pquery1);

  Array Reference
    You can create a pQuery object as an array of anything you want; not
    just pQuery::DOM elements. This can be useful to use the "each" method
    to iterate over the array.

        pQuery(\ @some_array);

  No Arguments
    Calling pQuery with no arguments will return a pQuery object that is
    just an empty array reference. This is useful for using it to call class
    methods that don't need a DOM object.

        my $html = pQuery->get("http://google.com")->content;

  PQUERY(@list_of_pQuery_constructor_args)
    The PQUERY constructor takes a list of any of the above pQuery forms and
    creates a PQUERY object with one pQuery object per argument.

METHODS
    This is a reference of all the methods you can call on a pQuery object.
    They are almost entirely ported from jQuery.

  pquery()
    Returns the version number of the pQuery module.

  size()
    Returns the number of elements in the pQuery object.

  length()
    Also returns the number of elements in the pQuery object.

  each($sub)
    This method takes a subroutine reference and calls the subroutine once
    for each member of the pQuery object that called "each". When the
    subroutine is called it is passed an integer count starting at 0 at
    incremented once for each call. It is also passed the current member of
    the pQuery object in $_.

        pQuery("td", $dom)->each(sub {
            my $i = shift;
            print $i, " => ", pQuery($_)->text(), "\n";
        });

    The "each" method returns the pQuery object that called it.

  EACH($sub)
    This method can only be called on PQUERY objects. The sub is called once
    for every pQuery object within the PQUERY object. If you call "each()"
    on a PQUERY object, it iterates on all the DOM objects of each pQuery
    object (as you would expect).

  find($selector)
    This method will search all the pQuery::DOM elements of the its caller
    for all sub elements that match the selector string. It will return a
    new pQuery object containing all the elements found.

        my $pquery2 = $pquery1->find("h1,h2,h3");

  html() html($html)
    This method is akin to the famous JavaScript/DOM function "innerHTML".

    If called with no arguments, this will return the the inner HTML string
    of the first DOM element in the pQuery object.

    If called with an HTML string argument, this will set the inner HTML of
    all the DOM elements in the pQuery object.

  toHtml()
    This extremely handy method is not ported from jQuery. Maybe jQuery will
    port it back some day. :)

    This function takes no arguments, and returns the outer HTML of the
    first DOM object in the pQuery object. Outer HTML means the HTML of the
    current object and its inner HTML.

    For example:

        pQuery('<p>I <b>like</b> pie</p>')->toHtml;

    returns:

        <p>I <b>like</b> pie</p>

    while:

        pQuery('<p>I <b>like</b> pie</p>')->html();

    returns:

        I <b>like</b> pie

  end()
    Revert the most recent 'destructive' operation, changing the set of
    matched elements to its previous state (right before the destructive
    operation). This method is useful for getting back to a prior context
    when chaining pQuery methods.

        pQuery("table", $dom)     # Select all the tables
            ->find("td")          # Select all the tds
            ->each(sub { ... })   # Do something with the tds
            ->end()               # Go back to the tables selection
            ->each(sub { ... });  # Do something with the tables

  get($index) get($url)
    If this method is passed an integer, it will return that specific
    element from the array of elements in the pQuery object.

    Givn a URL, this method will fetch the HTML content of the URL and
    return a HTML::Response object.

        my $html = pQuery->get("http://google.com")->content;

  index($elem)
    This method returns the index number of its argument if the elem is in
    the current pQuery object. Otherwise it returns -1.

UNDER CONSTRUCTION
    This module is still being written. The documented methods all work as
    documented (but may not be completed ports of their jQuery counterparts
    yet).

    The selector syntax is still very limited. (Single tags, IDs and classes
    only).

    Version 0.02 added the pQuery::DOM class which is a huge improvement,
    and should facilitate making the rest of the porting easy.

    But there is still much more code to port. Stay tuned...

AUTHOR
    Ingy döt Net <ingy@cpan.org>

COPYRIGHT AND LICENSE
    Copyright (c) 2008, 2011. Ingy döt Net.

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

    See http://www.perl.com/perl/misc/Artistic.html

Packages

No packages published

Languages

  • Perl 100.0%