# CGI::XMLForm - phpMan

## NAME
    [CGI::XMLForm] - Extension of CGI.pm which reads/generates formated XML.

    NB: This is a subclass of CGI.pm, so can be used in it's place.

## SYNOPSIS
      use [CGI::XMLForm];

      my $cgi = new [CGI::XMLForm];

      if ($cgi->param) {
            print $cgi->header, $cgi->pre($cgi->escapeHTML($cgi->toXML));
      }
      else {
            open(FILE, "test.xml") or die "Can't open: $!";
            my @queries = ('/a', '/a/b*', '/a/b/c*', /a/d');
        print $cgi->header,
                  $cgi->pre($cgi->escapeHTML(
                      join "\n", $cgi->readXML(*FILE, @queries)));
      }

## DESCRIPTION
    This module can either create form field values from XML based on
    XQL/XSL style queries (full XQL is _not_ supported - this module is
    designed for speed), or it can create XML from form values. There are 2
    key functions: toXML and readXML.

  toXML
    The module takes form fields given in a specialised format, and outputs
    them to XML based on that format. The idea is that you can create forms
    that define the resulting XML at the back end.

    The format for the form elements is:

      <input name="/body/p/ul/li">

    which creates the following XML:

      <body>
        <p>
              <ul>
                <li>Entered Value</li>
              </ul>
            </p>
      </body>

    It's the user's responsibility to design appropriate forms to make use
    of this module. Details of how come below...

    Also supported are attribute form items, that allow creation of element
    attributes. The syntax for this is:

      <input name="/body/p[@id='mypara' and @onClick='someFunc()']/@class">

    Which creates the following XML:

      <body>
        <p id="mypara" onClick="someFunc()" class="Entered Value"></p>
      </body>

    Also possible are relative paths. So the following form elements:

      <input type="hidden" name="/table/tr">
      <input type="text" name="td">
      <input type="text" name="td">
      <input type="text" name="../tr/td">

    Will create the following XML:

      <table>
        <tr>
              <td>value1</td>
              <td>value2</td>
            </tr>
            <tr>
              <td>value3</td>
            </tr>
      </table>

## SYNTAX
    The following is a brief syntax guideline

    Full paths start with a "/" :

      "/table/tr/td"

    Relative paths start with either ".." or just a tag name.

      "../tr/td"
      "td"

    Relative paths go at the level above the previous path, unless the
    previous path was also a relative path, in which case it goes at the
    same level. This seems confusing at first (you might expect it to always
    go at the level above the previous element), but it makes your form
    easier to design. Take the following example: You have a timesheet (see
    the example supplied in the archive) that has monday,tuesday,etc. Our
    form can look like this:

      <input type="text" name="/timesheet/projects/project/@Name">
      <input type="text" name="monday">
      <input type="text" name="tuesday">
      ...

    Rather than:

      <input type="text" name="/timesheet/projects/project/@Name">
      <input type="text" name="monday">
      <input type="text" name="../tuesday">
      <input type="text" name="../wednesday">
      ...

    If unsure I recommend using full paths, relative paths are great for
    repeating groups of data, but weak for heavily structured data. Picture
    the following paths:

      /timesheet/employee/name/forename
      ../surname
      title
      ../department

    This actually creates the following XML:

      <timesheet>
        <employee>
              <name>
                <forename>val1</forname>
                    <surname>val2</surname>
                    <title>val3></title>
              </name>
              <department>val4</department>
            </employee>
      </timesheet>

    Confusing eh? Far better to say:

      /timesheet/employee/name/forename
      /timesheet/employee/name/surname
      /timesheet/employee/name/title
      /timesheet/employee/department

    Or alternatively, better still:

      /timesheet/employee/name (Make hidden and no value)
      forename
      surname
      title
      ../department

    Attributes go in square brackets. Attribute names are preceded with an
    "@", and attribute values follow an "=" sign and are enclosed in quotes.
    Multiple attributes are separated with " and ".

      /table[@bgcolor="blue" and @width="100%"]/tr/td

    If setting an attribute, it follows after the tag that it is associated
    with, after a "/" and it's name is preceded with an "@".

      /table/@bgcolor

  readXML
    readXML takes either a file handle or text as the first parameter and a
    list of queries following that. The XML is searched for the queries and
    it returns a list of tuples that are the query and the match.

    It's easier to demonstrate this with an example. Given the following
    XML:

      <a>Foo
        <b>Bar
              <c>Fred</c>
              <c>Blogs</c>
            </b>
            <b>Red
              <c>Barbara</c>
              <c>Cartland</c>
            </b>
            <d>Food</d>
      </a>

    And the following queries:

      /a
      /a/b*
      c*
      /a/d

    it returns the following result as a list:

      /a
      Foo
      /a/b
      Bar
      c
      Fred
      c
      Blogs
      /a/b
      Red
      c
      Barbara
      c
      Cartland
      /a/d
      Food

    (NB: This is slightly incorrect - for /a and /a/b it will return "Foo\n
    " and "Bar\n " respectively).

    The queries support relative paths like toXML (including parent paths),
    and they also support wildcards using ".*" or ".*?" (preferably ".*?" as
    it's probably a better match). If a wildcard is specified the results
    will have the actual value substituted with the wildcard. Wildcards are
    a bit experimental, so be careful ;-)

  Caveats
    There are a few caveats to using this module:

    *   Parameters must be on the form in the order they will appear in the
        XML.

    *   There is no support for multiple attribute setting (i.e. you can
        only set one attribute for an element at a time).

    *   You can't set an attribute and a value for that element, it's one or
        the other.

    *   You can use this module in place of CGI.pm, since it's a subclass.

    *   There are bound to be lots of bugs! Although it's in production use
        right now - just watch CPAN for regular updates.

## AUTHOR
    Matt Sergeant <msergeant@ndirect.co.uk>, <sergeant@geocities.com>

    Based on an original concept, and discussions with, Jonathan Eisenzopf.
    Thanks to the Perl-XML mailing list for suggesting the XSL syntax.

    Special thanks to Francois Belanger (<francois@sitepak.com>) for his
    mentoring and help with the syntax design.

## SEE ALSO
    [CGI(1)], [CGI::XML]

