PHP XML操作类 xml2array -- 含节点属性

1. 单向xml2array函数

function xml2array($contents, $get_attributes=1, $priority = 'tag')
{
    if(!$contents) return array();

    if(!function_exists('xml_parser_create')) {
        //print "'xml_parser_create()' function not found!";
        return array();
    }

    //Get the XML parser of PHP - PHP must have this module for the parser to work
    $parser = xml_parser_create('');
    xml_parser_set_option($parser, XML_OPTION_TARGET_ENCODING, "UTF-8"); # http://minutillo.com/steve/weblog/2004/6/17/php-xml-and-character-encodings-a-tale-of-sadness-rage-and-data-loss
    xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);
    xml_parser_set_option($parser, XML_OPTION_SKIP_WHITE, 1);
    xml_parse_into_struct($parser, trim($contents), $xml_values);
    xml_parser_free($parser);

    if(!$xml_values) return;//Hmm...

    //Initializations
    $xml_array = array();
    $parents = array();
    $opened_tags = array();
    $arr = array();

    $current = &$xml_array; //Refference

    //Go through the tags.
    $repeated_tag_index = array();//Multiple tags with same name will be turned into an array
    foreach($xml_values as $data) {
        unset($attributes,$value);//Remove existing values, or there will be trouble

        //This command will extract these variables into the foreach scope
        // tag(string), type(string), level(int), attributes(array).
        extract($data);//We could use the array by itself, but this cooler.

        $result = array();
        $attributes_data = array();

        if(isset($value)) {
            if($priority == 'tag') $result = $value;
            else $result['value'] = $value; //Put the value in a assoc array if we are in the 'Attribute' mode
        }

        //Set the attributes too.
        if(isset($attributes) and $get_attributes) {
            foreach($attributes as $attr => $val) {
                if($priority == 'tag') $attributes_data[$attr] = $val;
                else $result['attr'][$attr] = $val; //Set all the attributes in a array called 'attr'
            }
        }

        //See tag status and do the needed.
        if($type == "open") {//The starting of the tag '<tag>'
            $parent[$level-1] = &$current;
            if(!is_array($current) or (!in_array($tag, array_keys($current)))) { //Insert New tag
                $current[$tag] = $result;
                if($attributes_data) $current[$tag. '_attr'] = $attributes_data;
                $repeated_tag_index[$tag.'_'.$level] = 1;

                $current = &$current[$tag];

            } else { //There was another element with the same tag name

                if(isset($current[$tag][0])) {//If there is a 0th element it is already an array
                    $current[$tag][$repeated_tag_index[$tag.'_'.$level]] = $result;
                    $repeated_tag_index[$tag.'_'.$level]++;
                } else {//This section will make the value an array if multiple tags with the same name appear together
                    $current[$tag] = array($current[$tag],$result);//This will combine the existing item and the new item together to make an array
                    $repeated_tag_index[$tag.'_'.$level] = 2;

                    if(isset($current[$tag.'_attr'])) { //The attribute of the last(0th) tag must be moved as well
                        $current[$tag]['0_attr'] = $current[$tag.'_attr'];
                        unset($current[$tag.'_attr']);
                    }

                }
                $last_item_index = $repeated_tag_index[$tag.'_'.$level]-1;
                $current = &$current[$tag][$last_item_index];
            }

        } elseif($type == "complete") { //Tags that ends in 1 line '<tag />'
            //See if the key is already taken.
            if(!isset($current[$tag])) { //New Key
                $current[$tag] = $result;
                $repeated_tag_index[$tag.'_'.$level] = 1;
                if($priority == 'tag' and $attributes_data) $current[$tag. '_attr'] = $attributes_data;

            } else { //If taken, put all things inside a list(array)
                if(isset($current[$tag][0]) and is_array($current[$tag])) {//If it is already an array...

                    // ...push the new element into that array.
                    $current[$tag][$repeated_tag_index[$tag.'_'.$level]] = $result;

                    if($priority == 'tag' and $get_attributes and $attributes_data) {
                        $current[$tag][$repeated_tag_index[$tag.'_'.$level] . '_attr'] = $attributes_data;
                    }
                    $repeated_tag_index[$tag.'_'.$level]++;

                } else { //If it is not an array...
                    $current[$tag] = array($current[$tag],$result); //...Make it an array using using the existing value and the new value
                    $repeated_tag_index[$tag.'_'.$level] = 1;
                    if($priority == 'tag' and $get_attributes) {
                        if(isset($current[$tag.'_attr'])) { //The attribute of the last(0th) tag must be moved as well

                            $current[$tag]['0_attr'] = $current[$tag.'_attr'];
                            unset($current[$tag.'_attr']);
                        }

                        if($attributes_data) {
                            $current[$tag][$repeated_tag_index[$tag.'_'.$level] . '_attr'] = $attributes_data;
                        }
                    }
                    $repeated_tag_index[$tag.'_'.$level]++; //0 and 1 index is already taken
                }
            }

        } elseif($type == 'close') { //End of tag '</tag>'
            $current = &$parent[$level-1];
        }
    }

    return($xml_array);
}

2. 双向xml2array和array2xml函数

<?php

###################################################################################
# xml2array: takes raw XML as a parameter (a string)
# and returns an equivalent PHP data structure
###################################################################################
function & xml2array(&$xml,$attr=true){
    $xml_parser = &new XML();
    $xml_parser->attr = $attr;
    $data = &$xml_parser->parse($xml);
    $xml_parser->destruct();
    return $data;
}
###################################################################################
# array2xml: serializes any PHP data structure into XML
# Takes one parameter: the data to serialize. Must be an array.
###################################################################################
function & array2xml(&$data, $level = 0, $prior_key = NULL){
    if($level == 0){ ob_start(); echo '<?xml version="1.0" ?>',"\n"; }
    while(list($key, $value) = each($data))
        if(!strpos($key, '_attr')) #if it's not an attribute
            #we don't treat attributes by themselves, so for an empty element
            # that has attributes you still need to set the element to NULL

            if(is_array($value) and array_key_exists(0, $value)){
                array2xml($value, $level, $key);
            }else{
                $tag = $prior_key ? $prior_key : $key;
                echo str_repeat("\t", $level),'<',$tag;
                if(array_key_exists($key.'_attr', $data)){ #if there's an attribute for this element
                    while(list($attr_name, $attr_value) = each($data[$key.'_attr']))
                        echo ' ',$attr_name,'="',htmlspecialchars($attr_value),'"';
                    reset($data[$key.'_attr']);
                }

                if(is_null($value)) echo " />\n";
                elseif(!is_array($value)) echo '>',htmlspecialchars($value),"</$tag>\n";
                else echo ">\n",array2xml($value, $level+1),str_repeat("\t", $level),"</$tag>\n";
            }
    reset($data);
    if($level == 0){ $str = &ob_get_contents(); ob_end_clean(); return $str; }
}
###################################################################################
# XML class: utility class to be used with PHP's XML handling functions
###################################################################################
class XML
{
    var $parser;   #a reference to the XML parser
    var $document; #the entire XML structure built up so far
    var $parent;   #a pointer to the current parent - the parent will be an array
    var $stack;    #a stack of the most recent parent at each nesting level
    var $last_opened_tag; #keeps track of the last tag opened.
    var $attr = true;

    function XML()
    {
        $this->parser = &xml_parser_create();
        xml_parser_set_option(&$this->parser, XML_OPTION_CASE_FOLDING, false);
        xml_set_object(&$this->parser, &$this);
        xml_set_element_handler(&$this->parser, 'open','close');
        xml_set_character_data_handler(&$this->parser, 'data');
    }
    function destruct(){ xml_parser_free(&$this->parser); }
    function & parse(&$data)
    {
        $this->document = array();
        $this->stack    = array();
        $this->parent   = &$this->document;
        return xml_parse(&$this->parser, &$data, true) ? $this->document : NULL;
    }
    function open(&$parser, $tag, $attributes)
    {
        $this->data = '';  
        #stores temporary cdata
        $this->last_opened_tag = $tag;
        #if you've seen this tag before
        if(is_array($this->parent) and array_key_exists($tag,$this->parent))
        {  
            #if the keys are numeric
            #this is the third or later instance of $tag we've come across
            if(is_array($this->parent[$tag]) and array_key_exists(0,$this->parent[$tag])) $key = $this->count_numeric_items($this->parent[$tag]);
            else
            {
                #this is the second instance of $tag that we've seen. shift around
                if(array_key_exists($tag.'_attr',$this->parent))
                {
                    $arr = array('0_attr'=>&$this->parent[$tag.'_attr'], &$this->parent[$tag]);
                    unset($this->parent[$tag.'_attr']);
                }
                else $arr = array(&$this->parent[$tag]);
                
                $this->parent[$tag] = &$arr;
                $key = 1;
            }
            $this->parent = &$this->parent[$tag];
        }
        else $key = $tag;

        if($attributes AND $this->attr) $this->parent[$key.'_attr'] = $attributes;
        $this->parent  = &$this->parent[$key];
        $this->stack[] = &$this->parent;
    }
    function data(&$parser, $data)
    {
        #you don't need to store whitespace in between tags
        if($this->last_opened_tag != NULL) $this->data .= $data;
    }
    function close(&$parser, $tag)
    {
        if($this->last_opened_tag == $tag)
        {
            $this->parent = $this->data;
            $this->last_opened_tag = NULL;
        }
        array_pop($this->stack);
        if($this->stack) $this->parent = &$this->stack[count($this->stack)-1];
    }
    function count_numeric_items(&$array)
    {
        return is_array($array) ? count(array_filter(array_keys($array), 'is_numeric')) : 0;
    }
}

1. <?php  
2. include('xml.php');  
3. $data = xml2array($xml);  
4. ?>