ILIAS  release_5-2 Revision v5.2.25-18-g3f80b828510
class.ilMathJax.php
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1<?php
2/* Copyright (c) 1998-2016 ILIAS open source, Extended GPL, see docs/LICENSE */
3
4// fau: mathJaxServer - new class for mathjax rendering.
5
10{
11 const PURPOSE_BROWSER = 'browser'; // direct display of page in the browser
12 const PURPOSE_EXPORT = 'export'; // html export of contents
13 const PURPOSE_PDF = 'pdf'; // server-side PDF generation
14 const PURPOSE_DEFERRED_PDF = 'deferred_pdf'; // defer rendering for server-side pdf generation (XSL-FO)
15 // this needs a second call with PURPOSE_PDF at the end
16
17 const ENGINE_SERVER = 'server'; // code is treated by one of the rendering modes below
18 const ENGINE_CLIENT = 'client'; // code delimiters are
19 const ENGINE_MIMETEX = 'mimetex'; // fallback to old mimetex cgi (if configured in ilias.ini.php)
20 const ENGINE_DEFERRED = 'deferred'; // protect code for a deferred rendering
21 const ENGINE_NONE = 'none'; // don't render the code, just show it
22
23 const RENDER_SVG_AS_XML_EMBED = 'svg_as_xml_embed'; // embed svg code directly in html (default for browser view)
24 const RENDER_SVG_AS_IMG_EMBED = 'svg_as_img_embed'; // embed svg base64 encoded in an img tag (default for HTML export)
25 const RENDER_SVG_AS_IMG_FILE = 'svg_as_img_file'; // refer to an svg file from an img tag (if called with output dir)
26
27 const RENDER_PNG_AS_IMG_EMBED = 'png_as_img_embed'; // embed png base64 encoded in an img tag (default for PDF generation)
28 const RENDER_PNG_AS_IMG_FILE = 'png_as_img_file'; // refer to a png file from an img tag (if called with output dir)
29 const RENDER_PNG_AS_FO_FILE = 'png_as_fo_file'; // refer to a png file from an fo tag (for PDF generation with XSL-FO)
30
34 protected static $_instance = null;
35
39 protected $settings = null;
40
44 protected $engine = null;
45
49 protected $mathjax_url = '';
50
54 protected $start_limiter = '';
55
59 protected $end_limiter = '';
60
64 protected $server_address = '';
65
69 protected $server_timeout = 5;
70
75
79 protected $output = 'svg';
80
84 protected $dpi = 150;
85
89 protected $zoom_factor = 1.0;
90
91
97 protected $mimetex_url = URL_TO_LATEX;
98
102 protected $mimetex_count = 0;
103
109 protected $use_curl = true;
110
114 protected $cache_dir = '';
115
119 protected $default_options = array(
120 "format" => "TeX",
121 "math" => '', // TeX code
122 "svg" => true,
123 "mml" => false,
124 "png" => false,
125 "speakText" => false,
126 "speakRuleset" => "mathspeak",
127 "speakStyle"=> "default",
128 "ex"=> 6,
129 "width"=> 1000000,
130 "linebreaks"=> false,
131 );
132
133
137 protected function __construct()
138 {
139 // initiate the settings for browser as default
140 include_once "./Services/Administration/classes/class.ilSetting.php";
141 $this->settings = new ilSetting("MathJax");
142 $this->init(self::PURPOSE_BROWSER);
143
144 // set the connection method
145 $this->use_curl = extension_loaded('cURL');
146
147 // set the cache directory
148 $this->cache_dir = ilUtil::getWebspaceDir() . '/temp/tex';
149 }
150
155 public static function getInstance()
156 {
157 if (self::$_instance === NULL) {
158 self::$_instance = new self;
159 }
160 return self::$_instance;
161 }
162
169 public function init($a_purpose = self::PURPOSE_BROWSER)
170 {
171 // reset the choice of a former initialisation
172 unset($this->engine);
173
174 // try server-side rendering first, set this engine, if possible
175 if ($this->settings->get('enable_server'))
176 {
177 $this->server_address = $this->settings->get('server_address');
178 $this->server_timeout = $this->settings->get('server_timeout');
179
180 if($a_purpose == self::PURPOSE_BROWSER && $this->settings->get('server_for_browser'))
181 {
182 $this->engine = self::ENGINE_SERVER;
183 // delivering svg directly in page may be faster than loading image files
184 $this->setRendering(self::RENDER_SVG_AS_XML_EMBED);
185 }
186 elseif($a_purpose == self::PURPOSE_EXPORT && $this->settings->get('server_for_export'))
187 {
188 $this->engine = self::ENGINE_SERVER;
189 // offline pages must always embed the svg as image tags
190 // otherwise the html base tag may conflict with references in svg
191 $this->setRendering(self::RENDER_SVG_AS_IMG_EMBED);
192 }
193 elseif($a_purpose == self::PURPOSE_PDF && $this->settings->get('server_for_pdf'))
194 {
195 $this->engine = self::ENGINE_SERVER;
196 // embedded png works in TCPDF and should work in most engines
197 $this->setRendering(self::RENDER_PNG_AS_IMG_EMBED);
198 $this->setDpi(600);
199 $this->setZoomFactor(0.17);
200
201 }
202 elseif ($a_purpose == self::PURPOSE_DEFERRED_PDF && $this->settings->get('server_for_pdf'))
203 {
204 $this->engine = self::ENGINE_DEFERRED;
205 }
206 }
207
208 // if server is not generally enabled or not activated for the intended purpose
209 // then set engine for client-side rendering, if possible
210 if (!isset($this->engine) && $this->settings->get('enable'))
211 {
212 $this->engine = self::ENGINE_CLIENT;
213 $this->mathjax_url = $this->settings->get('path_to_mathjax');
214 $this->includeMathJax();
215
216 switch ((int) $this->settings->get("limiter"))
217 {
218 case 1:
219 $this->start_limiter = "[tex]";
220 $this->end_limiter = "[/tex]";
221 break;
222
223 case 2:
224 $this->start_limiter = '<span class="math">';
225 $this->end_limiter = '</span>';
226 break;
227
228 default:
229 $this->start_limiter = "\‍(";
230 $this->end_limiter = "\‍)";
231 break;
232 }
233 }
234
235 // neither server nor client side rendering is enabled
236 // the use the older mimetex as fallback, if configured in ilias.ini.php
237 if (!isset($this->engine) && !empty($this->mimetex_url))
238 {
239 $this->engine = self::ENGINE_MIMETEX;
240 }
241
242 // no engine available or configured
243 if (!isset($this->engine))
244 {
245 $this->engine = self::ENGINE_NONE;
246 }
247
248 return $this;
249 }
250
251
257 public function setRendering($a_rendering)
258 {
259 switch($a_rendering)
260 {
264 $this->rendering = $a_rendering;
265 $this->output = 'svg';
266 break;
267
271 $this->rendering = $a_rendering;
272 $this->output = 'png';
273 break;
274 }
275 return $this;
276 }
277
283 public function setDpi($a_dpi)
284 {
285 $this->dpi = (float) $a_dpi;
286 return $this;
287 }
288
294 public function setZoomFactor($a_factor)
295 {
296 $this->zoom_factor = (float) $a_factor;
297 return $this;
298 }
299
305 public function includeMathJax($a_tpl = null)
306 {
307 global $tpl;
308
309 if ($a_tpl == null)
310 {
311 $a_tpl = $tpl;
312 }
313
314 if ($this->engine == self::ENGINE_CLIENT)
315 {
316 $a_tpl->addJavaScript($this->mathjax_url);
317 }
318 }
319
320
333 public function insertLatexImages($a_text, $a_start = '[tex]', $a_end = '[/tex]', $a_dir = null, $a_path = null)
334 {
335 // is this replacement still needed?
336 // it was defined in the old ilUtil::insertLatexImages function
337 // perhaps it was related to jsmath
338 if ($this->engine != self::ENGINE_MIMETEX)
339 {
340 $a_text = preg_replace("/\\\\([RZN])([^a-zA-Z]|<\/span>)/", "\\mathbb{"."$1"."}"."$2", $a_text);
341 }
342
343 // this is a fix for bug5362
344 $a_start = str_replace("\\", "", $a_start);
345 $a_end = str_replace("\\", "", $a_end);
346
347 $cpos = 0;
348 while (is_int($spos = stripos($a_text, $a_start, $cpos))) // find next start
349 {
350 if (is_int($epos = stripos($a_text, $a_end, $spos + strlen($a_start))))
351 {
352 // extract the tex code inside the delimiters
353 $tex = substr($a_text, $spos + strlen($a_start), $epos - $spos - strlen($a_start));
354
355 // undo a code protection done by the deferred engine before
356 if (substr($tex, 0, 7) == 'base64:')
357 {
358 $tex = base64_decode(substr($tex, 7));
359 }
360
361 // omit the html newlines added by the ILIAS page editor
362 // handle custom newlines in JSMath (still needed?)
363 $tex = str_replace('<br>', '', $tex);
364 $tex = str_replace('<br/>', '', $tex);
365 $tex = str_replace('<br />', '', $tex);
366 $tex = str_replace('\\\\' , '\\cr', $tex);
367
368 // replace, if tags do not go across div borders
369 if (!is_int(strpos($tex, '</div>')))
370 {
371 switch ($this->engine)
372 {
374 // prepare code for processing in the browser
375 // add necessary html encodings
376 // use the configured mathjax delimiters
377 $tex = str_replace('<', '&lt;', $tex);
378 $replacement = $this->start_limiter . $tex . $this->end_limiter;
379 break;
380
382 // apply server-side processing
383 // mathjax-node expects pure tex code
384 // so revert any applied html encoding
385 $tex = html_entity_decode($tex, ENT_QUOTES, 'UTF-8');
386 $replacement = $this->renderMathJax($tex, $a_dir, $a_path);
387 break;
388
390 // use mimetex
391 $replacement = $this->renderMimetex($tex, $a_dir, $a_path);
392 break;
393
395 // protect code to save it for post production
396 $replacement = '[tex]' . 'base64:' . base64_encode($tex) .'[/tex]';
397 break;
398
400 // show only the pure tex code
401 $replacement = htmlspecialchars($tex);
402 break;
403 }
404
405 // replace tex code with prepared code or generated image
406 $a_text = substr($a_text, 0, $spos) . $replacement . substr($a_text, $epos + strlen($a_end));
407 }
408 }
409 $cpos = $spos + 1;
410 }
411 return $a_text;
412 }
413
414
423 protected function renderMathJax($a_tex, $a_output_dir = null, $a_image_path = null)
424 {
426 $options['math'] = $a_tex;
427 $options['dpi'] = $this->dpi;
428
429 switch ($this->output)
430 {
431 case 'png':
432 $options['svg'] = false;
433 $options['png'] = true;
434 $suffix = ".png";
435 break;
436
437 case 'svg':
438 default:
439 $options['svg'] = true;
440 $options['png'] = false;
441 $suffix = ".svg";
442 break;
443 }
444
445 // store cached rendered image in cascading sub directories
446 $hash = md5($a_tex . '#' . $this->dpi);
447 $file = $this->cache_dir . '/' . substr($hash, 0, 4) . '/' . substr($hash, 4, 4) . '/' . $hash . $suffix;
448
449 try
450 {
451 if (!is_file($file))
452 {
453 // file has to be rendered
454 if ($this->use_curl)
455 {
456 $curl = curl_init($this->server_address);
457 curl_setopt($curl, CURLOPT_HEADER, false);
458 curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
459 curl_setopt($curl, CURLOPT_HTTPHEADER, array("Content-type: application/json"));
460 curl_setopt($curl, CURLOPT_POST, true);
461 curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($options));
462 curl_setopt($curl, CURLOPT_TIMEOUT, $this->server_timeout);
463
464 $response = curl_exec($curl);
465 $status = curl_getinfo($curl, CURLINFO_HTTP_CODE);
466 curl_close($curl);
467
468 if ($status != 200)
469 {
470 $lines = explode("\n", $response);
471 return "[TeX rendering failed: " . $lines[1] . " " . htmlspecialchars($a_tex) . "]";
472 }
473 }
474 else
475 {
476 $context = stream_context_create(
477 array(
478 'http' => array(
479 'method' => 'POST',
480 'content' => json_encode($options),
481 'header' => "Content-Type: application/json\r\n",
482 'timeout' => $this->server_timeout,
483 'ignore_errors' => true
484 )
485 ));
486 $response = @file_get_contents($this->server_address, false, $context);
487 if (empty($response))
488 {
489 return "[TeX rendering failed: " . htmlspecialchars($a_tex) . "]";
490 }
491 }
492
493 // create the parent directories recursively
494 @mkdir(dirname($file), 0777, true);
495
496 // save a rendered image to the temp folder
497 file_put_contents($file, $response);
498 }
499
500 // handle output of images for offline usage without embedding
501 if (isset($a_output_dir) && is_dir($a_output_dir))
502 {
503 @copy($file, $a_output_dir . '/' . $hash . $suffix);
504 $src = $a_image_path . '/' . $hash . $suffix;
505 }
506 else
507 {
508 $src = ILIAS_HTTP_PATH . '/' . $file;
509 }
510
511 // generate the image tag
512 switch ($this->output)
513 {
514 case 'png':
515 list($width, $height) = getimagesize($file);
516 $width = round($width * $this->zoom_factor);
517 $height = round($height * $this->zoom_factor);
518 $mime = 'image/png';
519 break;
520
521 case 'svg':
522 default:
523 $svg = simplexml_load_file($file);
524 $width = round($svg['width'] * $this->zoom_factor);
525 $height = round($svg['height'] * $this->zoom_factor);
526 $mime = 'image/svg+xml';
527 break;
528 }
529
530
531 // generate the image tag
532 switch ($this->rendering)
533 {
535 $html = empty($response) ? file_get_contents($file) : $response;
536 break;
537
540 $html = '<img src="data:' . $mime . ';base64,'
541 . base64_encode(empty($response) ? file_get_contents($file) : $response)
542 . '" style="width:' . $width . '; height:' . $height . ';" />';
543 break;
544
547 $html = '<img src="' . $src . '" style="width:' . $width . '; height:' . $height . ';" />';
548 break;
549
551 $html = '<fo:external-graphic src="url(' . realpath($file) . ')"'
552 . ' content-height="' . $height . 'px" content-width="' . $width . 'px"></fo:external-graphic>';
553 break;
554
555 default:
556 $html = htmlspecialchars($a_tex);
557 break;
558 }
559
560 return $html;
561 }
562 catch (Exception $e)
563 {
564 return "[TeX rendering failed: " . $e->getMessage() . "]";
565 }
566 }
567
568
577 protected function renderMimetex($a_tex, $a_output_dir = null, $a_image_path = null)
578 {
579 $call = $this->mimetex_url.'?'
580 .rawurlencode(str_replace('&amp;', '&', str_replace('&gt;', '>', str_replace('&lt;', '<', $a_tex))));
581
582 if (empty($a_output_dir))
583 {
584 $html = '<img alt="'.htmlentities($a_tex).'" src="'.$call.'" />';
585 }
586 else
587 {
588 $cnt = $this->mimetex_count++;
589
590 // get image from cgi and write it to file
591 $fpr = @fopen($call, "r");
592 $lcnt = 0;
593 if ($fpr)
594 {
595 while(!feof($fpr))
596 {
597 $buf = fread($fpr, 1024);
598 if ($lcnt == 0)
599 {
600 if (is_int(strpos(strtoupper(substr($buf, 0, 5)), "GIF")))
601 {
602 $suffix = "gif";
603 }
604 else
605 {
606 $suffix = "png";
607 }
608 $fpw = fopen($a_output_dir."/img".$cnt.".".$suffix, "w");
609 }
610 $lcnt++;
611 fwrite($fpw, $buf);
612 }
613 fclose($fpw);
614 fclose($fpr);
615 }
616
617 $html = '<img alt="'.htmlentities($a_tex).'" src='.$a_image_path.'/img"'.$cnt.'.'.$suffix.'/'.'" />';
618 }
619
620 return $html;
621 }
622
627 public function getCacheSize()
628 {
629 $cache_dir = realpath($this->cache_dir);
630
631 if (!is_dir($cache_dir))
632 {
633 $size = 0;
634 }
635 else
636 {
638 }
639
640 $type = array("k", "M", "G", "T");
641 $size = $size / 1024;
642 $counter = 0;
643 while($size >= 1024)
644 {
645 $size = $size / 1024;
646 $counter++;
647 }
648
649 return(round($size,1)." ".$type[$counter]."B");
650 }
651
655 function clearCache()
656 {
657 ilUtil::delDir($this->cache_dir);
658 }
659}
$size
Definition: RandomTest.php:79
global $tpl
Definition: ilias.php:8
An exception for terminatinating execution or to throw for unit testing.
Class for Server-side generation of latex formulas.
const RENDER_SVG_AS_IMG_FILE
static $_instance
renderMathJax($a_tex, $a_output_dir=null, $a_image_path=null)
Render image from tex code using the MathJax server.
renderMimetex($a_tex, $a_output_dir=null, $a_image_path=null)
Render image from tex code using mimetex.
includeMathJax($a_tpl=null)
Include Mathjax javascript in a template.
const ENGINE_NONE
setZoomFactor($a_factor)
Set the zoom factor for images.
const RENDER_SVG_AS_IMG_EMBED
init($a_purpose=self::PURPOSE_BROWSER)
Initialize the usage This must be done before any rendering call.
clearCache()
Clear the cache of rendered graphics.
setRendering($a_rendering)
Set the image type rendered by the server.
const ENGINE_SERVER
const ENGINE_CLIENT
static getInstance()
Singleton: get instance.
const RENDER_PNG_AS_IMG_FILE
const ENGINE_MIMETEX
const PURPOSE_PDF
const PURPOSE_DEFERRED_PDF
const RENDER_PNG_AS_IMG_EMBED
const RENDER_PNG_AS_FO_FILE
getCacheSize()
Get the size of the image cache.
const PURPOSE_BROWSER
const RENDER_SVG_AS_XML_EMBED
setDpi($a_dpi)
Set the dpi of the rendered images.
__construct()
Singleton: protected constructor.
const PURPOSE_EXPORT
insertLatexImages($a_text, $a_start='[tex]', $a_end='[/tex]', $a_dir=null, $a_path=null)
Replace tex tags with formula image code New version of ilUtil::insertLatexImages.
const ENGINE_DEFERRED
ILIAS Setting Class.
static delDir($a_dir, $a_clean_only=false)
removes a dir and all its content (subdirs and files) recursively
static getWebspaceDir($mode="filesystem")
get webspace directory
static dirsize($directory)
get size of a directory or a file.
$counter
$html
Definition: example_001.php:87
if(!file_exists("$old.txt")) if( $old===$new) if(file_exists("$new.txt")) $file
settings()
Definition: settings.php:2
if(!is_array($argv)) $options