xmd.lib.php

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        if (!is_string($name) || $name == '') return -1;
        
        if (($p = strrpos($name, ':')) !== FALSE)  // URI + ':' + name
            if ($p == 0 || $p == strlen($name) - 1) return -1;
        
        $child = ($this->_last += 1); $uris = array(); $uri = '';
        
        if ($p)
        {
            $uri = substr($name, 0, $p); $name = substr($name, $p + 1);
            $uris[] = $uri;  // check uris after defining all attributes
        }
        
        $this->parent[$child] = $parent; $this->name[$child] = $name;
        $this->ns[$child] = $uri ? $this->_lookup($uri) : 0;
        $this->children[$child] = array();
        
        $this->attributes[$child] = array(); $this->atns[$child] = array();
        
        foreach ($attribs as $name => $value)
            if (($uri = $this->xmd_set_attribute($child, $name, $value, FALSE)))
                $uris[] = $uri;  // check at end, not immediately
        
        if ($parent >= 0 && $parent <= $this->_last) 
            $this->children[$parent][] = $child;  // link to parent
        
        foreach ($uris as $uri) $this->_nsPfx($child, $uri);
        // find prefix (child and upwards) or create new prefix at root
        
        return $child;
    }
    
    
    function xmd_set_attribute($parent, $name, $value, $checkurihaspfx = TRUE)
    {
        if (!is_string($name) || $name == '') return '';
        
        if (($p = strrpos($name, ':')) !== FALSE)  // URI + ':' + name
            if ($p == 0 || $p == strlen($name) - 1) return '';
        
        $uri = '';  // beware of 'xmlns...', which is a namespace def!
        
        if ($p) if (substr($name, 0, 6) != 'xmlns:')
        {
            $uri = substr($name, 0, $p); $name = substr($name, $p + 1);
        }
        $this->attributes[$parent][$name] = $value;
        $this->atns[$parent][$name] = $uri ? $this->_lookup($uri) : 0;
        if ($checkurihaspfx) if ($uri) $this->_nsPfx($parent, $uri);
        
        if (substr($name, 0, 6) == 'xmlns:')  // namespace def with prefix
            $this->_nsp[substr($name, 6)] = $value;  // prefix is in use
        
        return $uri;
    }
    
    
    function xmd_add_text($text, $parent = 0)  // success = TRUE
    {
        if ($parent < 0 || $parent > $this->_last || !is_string($text))
            return FALSE;
    
        if ($text) $this->children[$parent][] = $text; return TRUE;
    }
    
    
    function xmd_add_text_element($name, $text, $parent = 0, $attribs = array())
    {
        $this->xmd_add_text($text, 
            $child = $this->xmd_add_element($name, $parent, $attribs));
    
        return $child;
    }
    
    
    function xmd_text($parent = 0)
    {
        if ($parent < 0 || $parent > $this->_last) return '';
        
        $text = '';  // assemble text subnodes and text in child elements
    
        foreach ($this->children[$parent] as $child)
            $text .= is_string($child) ? $child : $this->xmd_text($child);
        
        return $text;
    }
    
    
    function xmd_xml($increase = '  ', $indent = '', $lbr = "\n", $parent = 0)
    {
        if ($parent < 0 || $parent > $this->_last) return '';
        
        $uri = $this->names[$this->ns[$parent]];
        $pfxc = ($uri == '') ? '' : $this->_nsPfx($parent, $uri);
        
        $dbg = '';  // ($uri == '') ? '' : (' <!-- ' . $uri . ' -->');
        
        $result = $indent . '<' . ($element = $pfxc . $this->name[$parent]);
        
        $atnsp = $this->atns[$parent];
        
        foreach ($this->attributes[$parent] as $name => $value)
        {
            if (isset($atnsp[$name]))
            	$atnsn = $atnsp[$name];
            elseif (isset($atnsn))
            	unset($atnsn);
            $uri = isset($atnsn) && isset($this->names[$atnsn]) ? 
                $this->names[$atnsn] : '';
            $pfxc = ($uri == '') ? '' : $this->_nsPfx($parent, $uri);
            $result .= ' ' . $pfxc . $name 
                . '="' . htmlspecialchars($value) . '"';
        }
        
        if (count($this->children[$parent]) == 0)
            return $result . ' />' . $dbg;
        
        $result .= '>';
        
        foreach ($this->children[$parent] as $child)
            $result .= is_string($child) ? htmlspecialchars($child) : ($lbr . 
                $this->xmd_xml($increase, $indent.$increase, $lbr, $child));
        
        if (!is_string($child)) $result .= $lbr . $indent;  // last $child
        
        return $result . '</' . $element . '>' . $dbg; 
    }
    
    
    function xmd_value($xmPath, $parent = 0, $fix = array(), $fun = '')
    {
        // extensions:  @*[name] for element position (starts at 1)
        //              @. for element (tag)name
        
        if ($parent < 0 || $parent > $this->_last || !is_string($xmPath)) 
            return '';
        
        if (($p = strrpos($xmPath, '@')) !== FALSE)
        {
            $attName = substr($xmPath, $p+1); $xmPath = substr($xmPath, 0, $p);
        }
        
        if (!($elems = $this->xmd_select_elements($xmPath, $parent))) return '';
        
        $result = ''; $fixin = isset($fix['in']) ? $fix['in'] : '';
        
        foreach ($elems as $elem)
        {
            $value = isset($attName) && strlen($attName) >= 1 ?
                ($attName == '.' ? $this->name[$elem] : 
                    ($attName{0} == '*' ? 
                        $this->_sibnum($elem, substr($attName, 1)) :
                        $this->attributes[$elem][$attName])) : 
                $this->xmd_text($elem);
            $result .= $fixin . ($fun ? $fun($value) : $value);
        }
        
        return  (isset($fix['pre']) ? $fix['pre'] : '') . 
                substr($result, strlen($fixin)) . 
                (isset($fix['post']) ? $fix['post'] : '');
    }
    
    
    function xmd_html_value($xmPath, $parent = 0, $fun = 'htmlspecialchars')
    {
        if (!is_string($xmPath)) return '';
        
        $fix = array();
        
        if (($p = strpos($xmPath, ' -% ')) !== FALSE)
        {
            $fix['pre'] = substr($xmPath, 0, $p);
            $xmPath = substr($xmPath, $p+4);
        }
        if (($p = strpos($xmPath, ' %- ')) !== FALSE)
        {
            $fix['post'] = substr($xmPath, $p+4);
            $xmPath = substr($xmPath, 0, $p);
        }
        if (($p = strpos($xmPath, ' ')) !== FALSE)
        {
            $fix['in'] = substr($xmPath, $p+1);
            $xmPath = substr($xmPath, 0, $p);
        }
        
        return $this->xmd_value($xmPath, $parent, $fix, $fun);
    }
    
    
    function xmd_select_single_element($xmPath, $parent = 0)  // for convenience
    {
        $elements = $this->xmd_select_elements($xmPath, $parent);
        if (count($elements) == 0) return -1;
        return $elements[0];
    }
    
    
    function xmd_select_elements_where($xmPath, 
            $subPath = '.', $value = '', $parent = 0)
    {
        if (!is_string($subPath)) return array();
        
        $elems = array(); if ($subPath == '.') $subPath = '';
        
        foreach ($this->xmd_select_elements($xmPath, $parent) as $elem)
            if ($this->xmd_value($subPath, $elem) == $value) $elems[] = $elem;
        
        return $elems;
    }
    
    
    function xmd_select_elements_where_notempty($xmPath, 
            $subPath = '.', $parent = 0)
    {
        if (!is_string($subPath)) return array();
        
        $elems = array(); if ($subPath == '.') $subPath = '';
        
        foreach ($this->xmd_select_elements($xmPath, $parent) as $elem)
            if ($this->xmd_value($subPath, $elem)) $elems[] = $elem;
        
        return $elems;
    }
    
    
    function xmd_select_elements($xmPath, $parent = 0)
    {
        // XPath subset:    e1/e2/.../en, also * and e[n] and *[n] (at 1 or -1)
        //                  /*/... starts from root, regardless of $parent
        // extensions:      e= - or + (previous & next sibling)
        //                  e= -name or +name (sibling of specific name)
        //                  e= .. (stops at root, so too many doesn't matter)
        
        if (substr($xmPath, 0, 3) == '/*/')
        {
            $xmPath = substr($xmPath, 3); $parent = 0;
        }
        
        if ($parent < 0 || $parent > $this->_last) return array();
        
        while (substr($xmPath, 0, 1) == '/') $xmPath = substr($xmPath, 1);
        while (substr($xmPath, -1) == '/')   $xmPath = substr($xmPath, 0, -1);
        
        if ($xmPath == '' || $xmPath == '.') return array($parent);
        
        if ($xmPath == '..')
        {
            if ($parent > 0) return array($this->parent[$parent]);
            return array($parent);
        }
        
        if ($xmPath{0} == '-' || $xmPath{0} == '+')
        {
            $sib = $this->_sibnum($parent, substr($xmPath, 1), $xmPath{0});
            if ($sib == -1) return array(); return array($sib);
        }
        
        $m = array();
        if (ereg('^(.+)/([^/]+)$', $xmPath, $m))  // split on last /
        {
            if (!($set = $this->xmd_select_elements($m[1], $parent))) 
                return $set;  // which is empty array
            if (count($set) == 1) 
                return $this->xmd_select_elements($m[2], $set[0]);
            
            $bigset = array(); $m2 = $m[2];
            foreach ($set as $e)
                $bigset = array_merge($bigset, 
                    $this->xmd_select_elements($m2, $e));
            return $bigset;
        }
        
        $xmName = $xmPath; $xmNum = 0; $elems = array();
        
        if (ereg('^(.+)\[(-?[0-9]+)\]$', $xmPath, $m))
        {
            $xmName = $m[1]; $xmNum = (int) $m[2];
        }
        
        foreach ($this->children[$parent] as $child) if (!is_string($child))
            if ($xmName == '*' || ($this->name[$child]) == $xmName)
                $elems[] = $child;
        
        if ($xmNum == 0) return $elems;
        
        $xmNum = ($xmNum > 0) ? $xmNum - 1 : count($elems) + $xmNum;
        
        return ($xmNum < count($elems)) ? array($elems[$xmNum]) : array();
    }

    // Notes on parsing and caching: