1<?php
2/**
3 * Atom Syndication Format PHP Library
4 *
5 * @package AtomLib
6 * @link http://code.google.com/p/phpatomlib/
7 *
8 * @author Elias Torres <elias@torrez.us>
9 * @version 0.4
10 * @since 2.3.0
11 */
12
13/**
14 * Structure that store common Atom Feed Properties
15 *
16 * @package AtomLib
17 */
18class AtomFeed {
19	/**
20	 * Stores Links
21	 * @var array
22	 * @access public
23	 */
24    var $links = array();
25    /**
26     * Stores Categories
27     * @var array
28     * @access public
29     */
30    var $categories = array();
31	/**
32	 * Stores Entries
33	 *
34	 * @var array
35	 * @access public
36	 */
37    var $entries = array();
38}
39
40/**
41 * Structure that store Atom Entry Properties
42 *
43 * @package AtomLib
44 */
45class AtomEntry {
46	/**
47	 * Stores Links
48	 * @var array
49	 * @access public
50	 */
51    var $links = array();
52    /**
53     * Stores Categories
54     * @var array
55	 * @access public
56     */
57    var $categories = array();
58}
59
60/**
61 * AtomLib Atom Parser API
62 *
63 * @package AtomLib
64 */
65class AtomParser {
66
67    var $NS = 'http://www.w3.org/2005/Atom';
68    var $ATOM_CONTENT_ELEMENTS = array('content','summary','title','subtitle','rights');
69    var $ATOM_SIMPLE_ELEMENTS = array('id','updated','published','draft');
70
71    var $debug = false;
72
73    var $depth = 0;
74    var $indent = 2;
75    var $in_content;
76    var $ns_contexts = array();
77    var $ns_decls = array();
78    var $content_ns_decls = array();
79    var $content_ns_contexts = array();
80    var $is_xhtml = false;
81    var $is_html = false;
82    var $is_text = true;
83    var $skipped_div = false;
84
85    var $FILE = "php://input";
86
87    var $feed;
88    var $current;
89
90	/**
91	 * PHP5 constructor.
92	 */
93    function __construct() {
94
95        $this->feed = new AtomFeed();
96        $this->current = null;
97        $this->map_attrs_func = array( __CLASS__, 'map_attrs' );
98        $this->map_xmlns_func = array( __CLASS__, 'map_xmlns' );
99    }
100
101	/**
102	 * PHP4 constructor.
103	 */
104	public function AtomParser() {
105		self::__construct();
106	}
107
108	/**
109	 * Map attributes to key="val"
110	 *
111	 * @param string $k Key
112	 * @param string $v Value
113	 * @return string
114	 */
115	public static function map_attrs($k, $v) {
116		return "$k=\"$v\"";
117	}
118
119	/**
120	 * Map XML namespace to string.
121	 *
122	 * @param indexish $p XML Namespace element index
123	 * @param array $n Two-element array pair. [ 0 => {namespace}, 1 => {url} ]
124	 * @return string 'xmlns="{url}"' or 'xmlns:{namespace}="{url}"'
125	 */
126	public static function map_xmlns($p, $n) {
127		$xd = "xmlns";
128		if( 0 < strlen($n[0]) ) {
129			$xd .= ":{$n[0]}";
130		}
131		return "{$xd}=\"{$n[1]}\"";
132	}
133
134    function _p($msg) {
135        if($this->debug) {
136            print str_repeat(" ", $this->depth * $this->indent) . $msg ."\n";
137        }
138    }
139
140    function error_handler($log_level, $log_text, $error_file, $error_line) {
141        $this->error = $log_text;
142    }
143
144    function parse() {
145
146        set_error_handler(array(&$this, 'error_handler'));
147
148        array_unshift($this->ns_contexts, array());
149
150        if ( ! function_exists( 'xml_parser_create_ns' ) ) {
151        	trigger_error( __( "PHP's XML extension is not available. Please contact your hosting provider to enable PHP's XML extension." ) );
152        	return false;
153        }
154
155        $parser = xml_parser_create_ns();
156        xml_set_object($parser, $this);
157        xml_set_element_handler($parser, "start_element", "end_element");
158        xml_parser_set_option($parser,XML_OPTION_CASE_FOLDING,0);
159        xml_parser_set_option($parser,XML_OPTION_SKIP_WHITE,0);
160        xml_set_character_data_handler($parser, "cdata");
161        xml_set_default_handler($parser, "_default");
162        xml_set_start_namespace_decl_handler($parser, "start_ns");
163        xml_set_end_namespace_decl_handler($parser, "end_ns");
164
165        $this->content = '';
166
167        $ret = true;
168
169        $fp = fopen($this->FILE, "r");
170        while ($data = fread($fp, 4096)) {
171            if($this->debug) $this->content .= $data;
172
173            if(!xml_parse($parser, $data, feof($fp))) {
174                /* translators: 1: Error message, 2: Line number. */
175                trigger_error(sprintf(__('XML Error: %1$s at line %2$s')."\n",
176                    xml_error_string(xml_get_error_code($parser)),
177                    xml_get_current_line_number($parser)));
178                $ret = false;
179                break;
180            }
181        }
182        fclose($fp);
183
184        xml_parser_free($parser);
185        unset($parser);
186
187        restore_error_handler();
188
189        return $ret;
190    }
191
192    function start_element($parser, $name, $attrs) {
193
194        $name_parts = explode(":", $name);
195        $tag        = array_pop($name_parts);
196
197        switch($name) {
198            case $this->NS . ':feed':
199                $this->current = $this->feed;
200                break;
201            case $this->NS . ':entry':
202                $this->current = new AtomEntry();
203                break;
204        };
205
206        $this->_p("start_element('$name')");
207        #$this->_p(print_r($this->ns_contexts,true));
208        #$this->_p('current(' . $this->current . ')');
209
210        array_unshift($this->ns_contexts, $this->ns_decls);
211
212        $this->depth++;
213
214        if(!empty($this->in_content)) {
215
216            $this->content_ns_decls = array();
217
218            if($this->is_html || $this->is_text)
219                trigger_error("Invalid content in element found. Content must not be of type text or html if it contains markup.");
220
221            $attrs_prefix = array();
222
223            // resolve prefixes for attributes
224            foreach($attrs as $key => $value) {
225                $with_prefix = $this->ns_to_prefix($key, true);
226                $attrs_prefix[$with_prefix[1]] = $this->xml_escape($value);
227            }
228
229            $attrs_str = join(' ', array_map($this->map_attrs_func, array_keys($attrs_prefix), array_values($attrs_prefix)));
230            if(strlen($attrs_str) > 0) {
231                $attrs_str = " " . $attrs_str;
232            }
233
234            $with_prefix = $this->ns_to_prefix($name);
235
236            if(!$this->is_declared_content_ns($with_prefix[0])) {
237                array_push($this->content_ns_decls, $with_prefix[0]);
238            }
239
240            $xmlns_str = '';
241            if(count($this->content_ns_decls) > 0) {
242                array_unshift($this->content_ns_contexts, $this->content_ns_decls);
243                $xmlns_str .= join(' ', array_map($this->map_xmlns_func, array_keys($this->content_ns_contexts[0]), array_values($this->content_ns_contexts[0])));
244                if(strlen($xmlns_str) > 0) {
245                    $xmlns_str = " " . $xmlns_str;
246                }
247            }
248
249            array_push($this->in_content, array($tag, $this->depth, "<". $with_prefix[1] ."{$xmlns_str}{$attrs_str}" . ">"));
250
251        } else if(in_array($tag, $this->ATOM_CONTENT_ELEMENTS) || in_array($tag, $this->ATOM_SIMPLE_ELEMENTS)) {
252            $this->in_content = array();
253            $this->is_xhtml = $attrs['type'] == 'xhtml';
254            $this->is_html = $attrs['type'] == 'html' || $attrs['type'] == 'text/html';
255            $this->is_text = !in_array('type',array_keys($attrs)) || $attrs['type'] == 'text';
256            $type = $this->is_xhtml ? 'XHTML' : ($this->is_html ? 'HTML' : ($this->is_text ? 'TEXT' : $attrs['type']));
257
258            if(in_array('src',array_keys($attrs))) {
259                $this->current->$tag = $attrs;
260            } else {
261                array_push($this->in_content, array($tag,$this->depth, $type));
262            }
263        } else if($tag == 'link') {
264            array_push($this->current->links, $attrs);
265        } else if($tag == 'category') {
266            array_push($this->current->categories, $attrs);
267        }
268
269        $this->ns_decls = array();
270    }
271
272    function end_element($parser, $name) {
273
274        $name_parts = explode(":", $name);
275        $tag        = array_pop($name_parts);
276
277        $ccount = count($this->in_content);
278
279        # if we are *in* content, then let's proceed to serialize it
280        if(!empty($this->in_content)) {
281            # if we are ending the original content element
282            # then let's finalize the content
283            if($this->in_content[0][0] == $tag &&
284                $this->in_content[0][1] == $this->depth) {
285                $origtype = $this->in_content[0][2];
286                array_shift($this->in_content);
287                $newcontent = array();
288                foreach($this->in_content as $c) {
289                    if(count($c) == 3) {
290                        array_push($newcontent, $c[2]);
291                    } else {
292                        if($this->is_xhtml || $this->is_text) {
293                            array_push($newcontent, $this->xml_escape($c));
294                        } else {
295                            array_push($newcontent, $c);
296                        }
297                    }
298                }
299                if(in_array($tag, $this->ATOM_CONTENT_ELEMENTS)) {
300                    $this->current->$tag = array($origtype, join('',$newcontent));
301                } else {
302                    $this->current->$tag = join('',$newcontent);
303                }
304                $this->in_content = array();
305            } else if($this->in_content[$ccount-1][0] == $tag &&
306                $this->in_content[$ccount-1][1] == $this->depth) {
307                $this->in_content[$ccount-1][2] = substr($this->in_content[$ccount-1][2],0,-1) . "/>";
308            } else {
309                # else, just finalize the current element's content
310                $endtag = $this->ns_to_prefix($name);
311                array_push($this->in_content, array($tag, $this->depth, "</$endtag[1]>"));
312            }
313        }
314
315        array_shift($this->ns_contexts);
316
317        $this->depth--;
318
319        if($name == ($this->NS . ':entry')) {
320            array_push($this->feed->entries, $this->current);
321            $this->current = null;
322        }
323
324        $this->_p("end_element('$name')");
325    }
326
327    function start_ns($parser, $prefix, $uri) {
328        $this->_p("starting: " . $prefix . ":" . $uri);
329        array_push($this->ns_decls, array($prefix,$uri));
330    }
331
332    function end_ns($parser, $prefix) {
333        $this->_p("ending: #" . $prefix . "#");
334    }
335
336    function cdata($parser, $data) {
337        $this->_p("data: #" . str_replace(array("\n"), array("\\n"), trim($data)) . "#");
338        if(!empty($this->in_content)) {
339            array_push($this->in_content, $data);
340        }
341    }
342
343    function _default($parser, $data) {
344        # when does this gets called?
345    }
346
347
348    function ns_to_prefix($qname, $attr=false) {
349        # split 'http://www.w3.org/1999/xhtml:div' into ('http','//www.w3.org/1999/xhtml','div')
350        $components = explode(":", $qname);
351
352        # grab the last one (e.g 'div')
353        $name = array_pop($components);
354
355        if(!empty($components)) {
356            # re-join back the namespace component
357            $ns = join(":",$components);
358            foreach($this->ns_contexts as $context) {
359                foreach($context as $mapping) {
360                    if($mapping[1] == $ns && strlen($mapping[0]) > 0) {
361                        return array($mapping, "$mapping[0]:$name");
362                    }
363                }
364            }
365        }
366
367        if($attr) {
368            return array(null, $name);
369        } else {
370            foreach($this->ns_contexts as $context) {
371                foreach($context as $mapping) {
372                    if(strlen($mapping[0]) == 0) {
373                        return array($mapping, $name);
374                    }
375                }
376            }
377        }
378    }
379
380    function is_declared_content_ns($new_mapping) {
381        foreach($this->content_ns_contexts as $context) {
382            foreach($context as $mapping) {
383                if($new_mapping == $mapping) {
384                    return true;
385                }
386            }
387        }
388        return false;
389    }
390
391    function xml_escape($string)
392    {
393             return str_replace(array('&','"',"'",'<','>'),
394                array('&amp;','&quot;','&apos;','&lt;','&gt;'),
395                $string );
396    }
397}
398