<?php
/*
**	$Id$
**
**	Copyright (C) 1995-2007 by the ITools Authors.
**	This file is part of ITools - the Internet Tools Library
**
**	ITools is free software; you can redistribute it and/or modify
**	it under the terms of the GNU General Public License as published by
**	the Free Software Foundation; either version 3 of the License, or
**	(at your option) any later version.
**
**	ITools is distributed in the hope that it will be useful,
**	but WITHOUT ANY WARRANTY; without even the implied warranty of
**	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
**	GNU General Public License for more details.
**
**	You should have received a copy of the GNU General Public License
**	along with this program.  If not, see <http://www.gnu.org/licenses/>.
**
**	UltraHTML 3000 tool layer. Create functions for html tags.
**
**	new it_html;
**	echo html(head('title' => 'hello'), body(h1('hello'), p('Hello world!')));
**/

class it_html
{

/**
 * Create a HTML object and global functions for all methods (exlcluding
 * methods starting with '_') in this class plus the default tags (see below).
 *
 * @param $p Configuration settings. Can be set/overridden in constructor, configure(), html() or head().
 *           See source code for a list of supported values
 */
function it_html($p = array())
{
	# Default configuration of html class
	$this->p = $p + array(
		'charset' => 'iso-8859-1',
		'doctype' => null,                    # Custom doctype (will usually be calculated from htmltype)
		'head' => '',                         # Code to put into head() section
		'htmltype' => 'xhtml',                # 'html' (=old-style), 'xhtml' or 'xhtml-mobile'
		'lang' => 'de',                       # Language code to use in <html lang="..."> tag
		'ie_png_fix' => false,                # To enable, supply URL of a transparent gif (like /images/0.gif)
		'moretags' => '',                     # Comma-separated list of tag-functions to generate additionally to 'tags'
		'name' => 'it_html',                  # Name of global variable $this is assigned to (string), XXX Copy and paste in configure() to keep PHP4 compatibility
		'nonewlinetags' => 'a,b,em,img,input,span', # tags that do not like newlines after them
		'notexported' => 'configure,sanitize',# Those methods are not exported
		'prettyprint' => false,               # Should output be prettily indented?
		'show_boot_dom' => false,             # If true, append invisible <div id="it_boot_dom"> at the end of body
		'show_content_type' => true,          # If true, add <meta http-equiv="Content-Type" ...> header
		'show_favicon' => true,               # If true, add <link> tag to /favicon.ico if it exists
		'staticallycallable' => 'q,u,select', # Those methods are statically callable (have same arguments as global stubs) but are a bit slower
		'tags' => 'a,b,br,button,div,em,fieldset,form,h1,h2,h3,h4,h5,h6,hr,input,label,legend,li,meta,noscript,p,span,style,table,td,textarea,th,tr,ul',
		'title' => '',                        # HTML title (default: no title added)
		'use_it_state' => false,              # If true, generate code needed by state.js (aka 'history iframe')
		'autoquote' => false,                 # Automatically pass plain strings through Q()
		'reportquote' => 0,                   # Report plain strings with this error level (e.g. E_USER_NOTICE)
	);

	# We know these doctypes. If you need something else, supply 'doctype' in p
	$this->doctypes = array(
		'html'		=> '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">',
		'xhtml'		=> '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">',
		'xhtml-mobile'	=> '<!DOCTYPE html PUBLIC "-//WAPFORUM//DTD XHTML Mobile 1.0//EN" "http://www.wapforum.org/DTD/xhtml-mobile10.dtd">'
	);

	$this->hasnonewline = array_flip(explode(',', $this->p['nonewlinetags']));
	$notexported = array_flip(explode(',', "dummy," . $this->p['notexported']));		# dummy keeps values > 0

	# Create global functions for _tags
	foreach (array_merge(explode(',', $this->p['tags']), explode(',', $this->p['moretags'])) as $func)
	{
		if (!function_exists($func) && $func)
			$code[$func] = "function $func() { \$args = func_get_args(); return new it_tag('$func', \$args); }";
	}

	# Create global functions for it_html methods
	foreach (get_class_methods(get_class($this)) as $func)
	{
		if (!preg_match('/^_/', $func) && !is_a($this, $func) && $func && !function_exists($func) && !$notexported[$func])
			$code[$func] = "function $func() { \$args = func_get_args(); return \$GLOBALS['{$this->p['name']}']->$func(\$args); }";
	}

	# Create global functions for methods that are statically callable (have same arguments as global stubs)
	foreach (explode(',', $this->p['staticallycallable']) as $func)
	{
		if ($func && !function_exists($func))
			$code[$func] = "function $func() { \$args = func_get_args(); return call_user_func_array(array(&\$GLOBALS['{$this->p['name']}'], '$func'), \$args); }";
	}

	eval(join('', (array)$code));

	# Since name is given as param, it is our duty to store it, not our caller's.
	$GLOBALS[$this->p['name']] =& $this;
}


/**
 * Modify configuration of it_html, e.g. htmltype after it was instantiated.
 * @param $p Configuration settings. Can be set/overridden in constructor, configure(), html() or head().
 *           See constructor for a list of supported values
 */
function configure($p)
{
	$p += array('name' => "it_html");	# XXX Copy and paste from constructor to keep PHP4 compatibility
	$GLOBALS[$p['name']]->p = $p + (array)$GLOBALS[$p['name']]->p;
	$GLOBALS[$p['name']]->hasnonewline = array_flip(explode(',', $GLOBALS[$p['name']]->p['nonewlinetags']));
}

/**
 * Return doctype and entire HTML page.
 * Example application code to render page:
 *     echo html(head(...), body(...));
 *
 * @param any number of text args or array of key => value pairs
 * Defaults for key => value parameters are inherited from the it_html constructor and should be set there.
 * The parameters are $p['lang'], $p['htmltype'] and $p['doctype']
 */
function html($args)
{
	$result = new it_tag('html');

	list($data, $p) = $this->_parse_args($args);
	$p += $this->p;

	$result->prefix = EDC('upd') ? "" : (($p['doctype'] ? $p['doctype'] : $this->doctypes[$p['htmltype']]) . "\n");

	if ($p['htmltype'] == "xhtml")
		$result['xmlns'] = "http://www.w3.org/1999/xhtml";

	$result[$p['htmltype'] == "xhtml-mobile" ? "xml:lang" : "lang"] = $p['lang'];
	$result[] = $data;

	return $result;
}


/**
 * Return HTML header on first call or empty string on subsequent calls
 *
 * @param args... any number of assoc arrays and strings. strings will be content of <head>
 * @param $p['content-type']  content type (default: "text/html; charset=iso-8859-1")
 * @param $p['cssinline']     stylesheet to be put in header
 * @param $p['description']   data for <meta name="description"> tag
 * @param $p['keywords']      data for <meta name="keywords"> tag
 * @param $p['stylesheets']   array mediatype => url of styleshests
 * @param $p['title']         content of <title>, will be html encoded
 */
function head($args = array())
{
	$result = array();

	if (!$this->head_sent++)
	{
		$result = new it_tag('head');

		list($data, $p) = $this->_parse_args($args);

		$p += $this->p;
		$this->p = ($p += array('content-type' => "text/html; charset={$p['charset']}"));

		if ($p['show_content_type'])
			$result[] = new it_tag('meta', array('http-equiv' => "Content-Type", 'content' => $p['content-type']));

		foreach(array('description', 'keywords') as $name)
			if (!empty($p[$name]))
				$result[] = new it_tag('meta', array('name' => $name, 'content' => $p[$name]));


		# Add favicon if file exists
		if ($p['show_favicon'] && @file_exists($_SERVER['DOCUMENT_ROOT'] . '/favicon.ico'))
			$result[] = new it_tag('link', array('rel' => "shortcut", 'href' => "/favicon.ico"));

		foreach((array)$p['stylesheets'] as $type => $url)
			$result[] = new it_tag('link', array('rel' => "stylesheet", 'type' => "text/css", 'href' => $url) + (is_int($type) ? array() : array('media' => $type)));

		if (!empty($p['cssinline']))
			$result[] = new it_tag('style', array('type' => "text/css", "\n" . preg_replace(array('/\s*\/\*[^\*]+\*\//Um', '/\s*\{\s*/', '/;\s+/'), array('', '{', ';'), $p['cssinline'])));


		if ($p['head'])
			$result[] = $p['head'];

		$result[] = new it_tag('title', new it_q($p['title']));

		if($this->p['htmltype'] == "xhtml-mobile" && strpos($_SERVER['HTTP_USER_AGENT'], 'W3C_Validator'))
			header("Content-Type: application/xhtml+xml; charset={$this->p['charset']}"); # for validation
		else if (!headers_sent()) # prevent warnings when ED() in use
			header("Content-Type: " . $p['content-type']);

		$js = $p['jsenv'] ? "var env = " . itjs::serialize($p['jsenv']) . ";\n" : '';

		if ($p['js'])
		{
			$checksum = itjs::checksum(itjs::filenames($p['js']));
			$js .= $this->_itjs("boot.js", "inline");
			$js .= "function it_boot_start(){ " . trim($p['jsboot']) . " }\n";
			$js .= "it_boot('/itjs/" . U($p['js'], array('s' => $checksum)) . "');\n";
		}

		$js .= $this->_itjs($p['jsinline'], 'inline');

		if ($js)
			$result[] = $this->js(array($js));

		foreach ($data as $value)
			$result[] = $value;
	}

	return $result;
}


/**
 * Return HTML head (if not already sent) and body with it_state and it_boot magic code
 */
function body($args)
{
	$result = $this->head();

	if ($this->p['use_it_state'])
		array_unshift($args, new it_tag('iframe', array('id' => "it_state", 'src' => "/itjs/state.html", 'width' => 1, 'height' => 1, 'frameborder' => 0)));

	if ($this->p['show_boot_dom'])
		$args[] = new it_tag('div', array('id' => "it_boot_dom", 'style' => "visibility:hidden"));

	$result[] = new it_tag('body', $args);

	return $result;
}


/**
 * INTERNAL: Parse an arg array (mixed key=>value pairs and strings) and return it
 * as array(0 => all numerical args concatenated, 1 => array(key=>value pairs)
 */
function _parse_args($args)
{
	$p = array();
	$data = array();

	foreach ($args as $arg)
	{
		if (is_array($arg))
		{
			foreach ($arg as $key => $value)
			{
				if (is_int($key))
					$data[] = $value;
				else
					$p[$key] = $value;
			}
		}
		else
			$data[] = $arg;
	}

	return array($data, $p);
}


/**
 * function div($args...)
 * Return a <div>...</div> element
 * Any strings in the argument list will be content of the <div>
 * Any associative arrays among the arguments will create attributes for <div>.
 * Attributes with values false or null will be omitted completely.
 * Attributes with value true can be used for boolean attributes like 'checked'
 * Attribute values will be html encoded, content values won't so you may need to use Q(). 
 * @see _tag()
 */ #:}


/**
 * Return a <tag> containing optional data.
 * @param $name tag name ('style', etc.)
 * @param ... any number optional data or array of key => value arguments
 * @return string containing XML/HTML tag
 */
function tag($args)
{
	$name = array_shift($args);
	return new it_tag($name, $args);
}

/**
 * Special img() function patches png transparency for IE 5.5-6 if ie_png_fix is set
 * @param ... any number optional data or array of key => value arguments
 * @return <img ... />
 */
function img($args)
{
	if ($this->p['ie_png_fix'] && preg_match('/MSIE [56]/', $_SERVER['HTTP_USER_AGENT']))
	{
		foreach($args as $id => $arg)
		{
			if (preg_match('/\.png(\?.*)?$/', $arg['src']))
			{
				$args[$id]['style'] = "filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='{$arg['src']}',sizingMethod='scale');" . $arg['style'];
				$args[$id]['src'] = $this->p['ie_png_fix'];
			}
		}
	}

	return new it_tag("img", $args);
}


/**
 * Create a dropdown menu object. Warning: encodes html code within options!
 * @param $tags key => value pairs of <select> tag
 * @param $options array (value => text) of available options or
 *        string key:val{,key:val} where key will be rawurldecoded so it may contain %2C as comma
 *        supports optgroups as array (value => optgroup => array(value => text))
 * @param $selected optional currently selected value, or comma-separated list or array for multi-select
 * Note: use tag('select') and tag('option') if you want do roll your own
 */
function select($tags, $options, $selected = null)
{
	$result = array();

	# Transmogrify key:val{,key:val} to array(key => val)
	if (!is_array($options))
	{
		$opts = explode(',', $options);
		$options = array();

		foreach($opts as $opt)
		{
			list($key, $value) = explode(':', $opt);
			$options[rawurldecode($key)] = $value;
		}
	}

	$selected = ($tags['multiple'] && is_string($selected)) ? explode(',', $selected) : (array)$selected;

	$html = "";
	foreach($options as $value => $option)
	{
		if (is_array($option))
		{
			$group = new it_tag('optgroup', array('label' => $value));
			foreach($option as $optval => $opt)
				$group[] = new it_tag("option", array(array('value' => $optval, 'selected' => in_array((string)$optval, $selected)), new it_q($opt)));
			$result[] = $group;
		}
		else
			$result[] = new it_tag("option", array(array('value' => $value, 'selected' => in_array((string)$value, $selected), 'disabled' => $option === ""), (trim($option) === "") ? "&nbsp;" : new it_q($option)));
	}

	return new it_tag("select", array($tags, $result));
}


/**
 * Return HTML with all evil things stripped. Allowed are a coupld of simple
 * tags like div, p, i, b, br without attributes, a with absolute href,
 * img with absolute src url. Also ensures that tags are balanced.
 * @param $html HTML string to be sanitized
 * @return Sanitized HTML
 */
function sanitize($html)
{
	$result = "";
	$html = it::replace(array('[\0\s]+' => " "), $html);	# \s also matches \r and \n
	$urlpattern = 'https?://[^">]+';

	if ($tag = it::match("(.*)<(div|p|i|b)[^>]*>(.*?)</\\2>(.*)", $html))
	{
		# Simple tags with content, no attributes kept
		list($head, $tagname, $content, $tail) = $tag;
		$tagname = strtolower($tagname);
		$result .= it_html::sanitize($head) . "<$tagname>" . it_html::sanitize($content) . "</$tagname>" . it_html::sanitize($tail);
	}
	else if ($tag = it::match('(.*)<a[^>]+?href="(' . $urlpattern . ')"[^>]*?>(.*?)</a>(.*)', $html))
	{
		# Link tags, keeps only href attribute
		list($head, $href, $content, $tail) = $tag;
		$result .= it_html::sanitize($head) . '<a href="' . new it_q(html_entity_decode($href)) . '">' . it_html::sanitize($content) . "</a>" . it_html::sanitize($tail);
	}
	else if ($tag = it::match('(.*)<img[^>]+?src="(' . $urlpattern . ')"[^>]*?>(.*)', $html))
	{
		# Image tags, keeps only src attribute
		list($head, $src, $tail) = $tag;
		$result .= it_html::sanitize($head) . '<img src="' . new it_q(html_entity_decode($src)) . '" alt="" />' . it_html::sanitize($tail);
	}
	else if ($tag = it::match("(.*)<(br)[^>]*>(.*)", $html))
	{
		# Simple tags without content, no attributes kept
		list($head, $tagname, $tail) = $tag;
		$tagname = strtolower($tagname);
		$result .= it_html::sanitize($head) . "<$tagname />" . it_html::sanitize($tail);
	}
	else
		$result = new it_q(it::replace(array('&#\d+;' => ""), html_entity_decode(strip_tags($html))));

	return $result;
}


/**
 * Shortcut: return htmlspecialchars($string) and encode forbidden characters 80-9f if latin1 is output
 * @param $args Data to encode with htmlspecialchars()
 * @return htmlspecialchars($args)
 */
function q($args)
{
	$args = (array)$args;
	return new it_q($args[0]);
}

/**
 * Mark text as not to be encoded (e.g. html from db)
 * @param $args Data not to be encoded
 * @return Data marked as not to be encoded
 */
function nq($args)
{
	$args = (array)$args;
	return new it_q($args[0], false);
}


/**
 * Build a complete url from base-url and params
 * @param ... scalar args and numeric indices build base-url, rest as params
 */
function u(/* ... */)
{
	$args = func_get_args();
	list($base, $params) = it_html::_parse_args($args);

	$base = count($base) == 0 ? $_SERVER['PHP_SELF'] : join("", $base);
	$base = preg_replace('|\0|', '', $base);
	$base = preg_replace('|[^\w.+!*(),:?@&=/~$-]|e', 'urlencode("$0")', $base);
	$base = preg_replace('|^(\w+:)?//[^/]*$|', '$0/', $base);	# Add slash if absolute url without a path, e.g. http://gna.ch
	$queryparams = it_url::params($params);
	$separator = strpos($base, "?") === false ? "?" : "&";

	return $base . ($queryparams ? "$separator$queryparams" : "");
}


/**
 * Insert a javascript script
 * @param ... any number optional data or array of key => value arguments
 * @return <script type="text/javascript"...>...</script>
 */
function js($args)
{
	if (($this->p['htmltype'] != 'html') && $args[0] && ((array)$args[0] === array_values((array)$args[0])))
	{
		array_unshift($args, "<!--//--><![CDATA[//><!--\n");
		$args[] = "\n//--><!]]>";
	}

	array_unshift($args, array('type' => 'text/javascript'));
	return new it_tag('script', $args);
}


/**
 * Include javascript code or generate HTML to include it
 */
function _itjs($files, $mode)
{
	$result = "";

	if ($files)
	{
		$filenames = itjs::filenames($files);

		if ($mode == "files")
		{
			foreach ($filenames as $file)
				$result .= new it_tag('script', array('type' => "text/javascript", 'src' => "/itjs/" . basename($file) . "?v=" . itjs::checksum($file)));
		}
		else if ($mode == "inline")
		{
			$jsfile = "";

			foreach ($filenames as $file)
				$jsfile .= @file_get_contents($file);

			$result .= itjs::strip($jsfile);
		}
		else
			$result .= new it_tag('script', array('type' => "text/javascript", 'src' => "/itjs/$files?v=" . itjs::checksum($filenames)));
	}

	return $result;
}

}
?>