Array2XML: convert PHP Array to XML (with attributes)

← Go back to blog post

Source code Version: 0.8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
<?php
/**
 * Array2XML: A class to convert array in PHP to XML
 * It also takes into account attributes names unlike SimpleXML in PHP
 * It returns the XML in form of DOMDocument class for further manipulation.
 * It throws exception if the tag name or attribute name has illegal chars.
 *
 * Author : Lalit Patel
 * Website: http://www.lalit.org/lab/convert-php-array-to-xml-with-attributes
 * License: Apache License 2.0
 *          http://www.apache.org/licenses/LICENSE-2.0
 * Version: 0.1 (10 July 2011)
 * Version: 0.2 (16 August 2011)
 *          - replaced htmlentities() with htmlspecialchars() (Thanks to Liel Dulev)
 *          - fixed a edge case where root node has a false/null/0 value. (Thanks to Liel Dulev)
 * Version: 0.3 (22 August 2011)
 *          - fixed tag sanitize regex which didn't allow tagnames with single character.
 * Version: 0.4 (18 September 2011)
 *          - Added support for CDATA section using @cdata instead of @value.
 * Version: 0.5 (07 December 2011)
 *          - Changed logic to check numeric array indices not starting from 0.
 * Version: 0.6 (04 March 2012)
 *          - Code now doesn't @cdata to be placed in an empty array
 * Version: 0.7 (24 March 2012)
 *          - Reverted to version 0.5
 * Version: 0.8 (02 May 2012)
 *          - Removed htmlspecialchars() before adding to text node or attributes.
 *
 * Usage:
 *       $xml = Array2XML::createXML('root_node_name', $php_array);
 *       echo $xml->saveXML();
 */
 
class Array2XML {
 
    private static $xml = null;
	private static $encoding = 'UTF-8';
 
    /**
     * Initialize the root XML node [optional]
     * @param $version
     * @param $encoding
     * @param $format_output
     */
    public static function init($version = '1.0', $encoding = 'UTF-8', $format_output = true) {
        self::$xml = new DomDocument($version, $encoding);
        self::$xml->formatOutput = $format_output;
		self::$encoding = $encoding;
    }
 
    /**
     * Convert an Array to XML
     * @param string $node_name - name of the root node to be converted
     * @param array $arr - aray to be converterd
     * @return DomDocument
     */
    public static function &createXML($node_name, $arr=array()) {
        $xml = self::getXMLRoot();
        $xml->appendChild(self::convert($node_name, $arr));
 
        self::$xml = null;    // clear the xml node in the class for 2nd time use.
        return $xml;
    }
 
    /**
     * Convert an Array to XML
     * @param string $node_name - name of the root node to be converted
     * @param array $arr - aray to be converterd
     * @return DOMNode
     */
    private static function &convert($node_name, $arr=array()) {
 
        //print_arr($node_name);
        $xml = self::getXMLRoot();
        $node = $xml->createElement($node_name);
 
        if(is_array($arr)){
            // get the attributes first.;
            if(isset($arr['@attributes'])) {
                foreach($arr['@attributes'] as $key => $value) {
                    if(!self::isValidTagName($key)) {
                        throw new Exception('[Array2XML] Illegal character in attribute name. attribute: '.$key.' in node: '.$node_name);
                    }
                    $node->setAttribute($key, self::bool2str($value));
                }
                unset($arr['@attributes']); //remove the key from the array once done.
            }
 
            // check if it has a value stored in @value, if yes store the value and return
            // else check if its directly stored as string
            if(isset($arr['@value'])) {
                $node->appendChild($xml->createTextNode(self::bool2str($arr['@value'])));
                unset($arr['@value']);    //remove the key from the array once done.
                //return from recursion, as a note with value cannot have child nodes.
                return $node;
            } else if(isset($arr['@cdata'])) {
                $node->appendChild($xml->createCDATASection(self::bool2str($arr['@cdata'])));
                unset($arr['@cdata']);    //remove the key from the array once done.
                //return from recursion, as a note with cdata cannot have child nodes.
                return $node;
            }
        }
 
        //create subnodes using recursion
        if(is_array($arr)){
            // recurse to get the node for that key
            foreach($arr as $key=>$value){
                if(!self::isValidTagName($key)) {
                    throw new Exception('[Array2XML] Illegal character in tag name. tag: '.$key.' in node: '.$node_name);
                }
                if(is_array($value) && is_numeric(key($value))) {
                    // MORE THAN ONE NODE OF ITS KIND;
                    // if the new array is numeric index, means it is array of nodes of the same kind
                    // it should follow the parent key name
                    foreach($value as $k=>$v){
                        $node->appendChild(self::convert($key, $v));
                    }
                } else {
                    // ONLY ONE NODE OF ITS KIND
                    $node->appendChild(self::convert($key, $value));
                }
                unset($arr[$key]); //remove the key from the array once done.
            }
        }
 
        // after we are done with all the keys in the array (if it is one)
        // we check if it has any text value, if yes, append it.
        if(!is_array($arr)) {
            $node->appendChild($xml->createTextNode(self::bool2str($arr)));
        }
 
        return $node;
    }
 
    /*
     * Get the root XML node, if there isn't one, create it.
     */
    private static function getXMLRoot(){
        if(empty(self::$xml)) {
            self::init();
        }
        return self::$xml;
    }
 
    /*
     * Get string representation of boolean value
     */
    private static function bool2str($v){
        //convert boolean to text value.
        $v = $v === true ? 'true' : $v;
        $v = $v === false ? 'false' : $v;
        return $v;
    }
 
    /*
     * Check if the tag name or attribute name contains illegal characters
     * Ref: http://www.w3.org/TR/xml/#sec-common-syn
     */
    private static function isValidTagName($tag){
        $pattern = '/^[a-z_]+[a-z0-9\:\-\.\_]*[^:]*$/i';
        return preg_match($pattern, $tag, $matches) && $matches[0] == $tag;
    }
}
?>