pQuery - A port of jQuery.js to Perl


    This document describes pQuery version 0.24.


        use pQuery;
            ->each(sub {
                my $i = shift;
                print $i + 1, ") ", pQuery($_)->text, "\n";


    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

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


    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 "$_/", qw(ingy gugod miyagawa))\
                printf("%40s - %s Perl distributions\n", $_->url, $_->length - 1)\
          - 88 Perl distributions
         - 86 Perl distributions
      - 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.


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


    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.


    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.


    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>");


    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.


 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("")->content;


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


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


      Returns the version number of the pQuery module.


      Returns the number of elements in the pQuery object.


      Also returns the number of elements in the pQuery object.


      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.


      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).


      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.


      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;


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


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


          I <b>like</b> pie


      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.

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

          my $html = pQuery->get("")->content;


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


      This method releases resources associated with pQuery and prevents
      memory leaks.


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

    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...


    Ingy döt Net <>


    Copyright 2008-2016. Ingy döt Net.

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