From 4a94909cc5ed57264d7279049facc25936521f03 Mon Sep 17 00:00:00 2001
From: Xinyu Jiang <125269853+xjiang-at-wiris@users.noreply.github.com>
Date: Thu, 31 Oct 2024 10:43:12 +0100
Subject: [PATCH] fix: Render latex on php mode (#162)

* feature: render latex on php mode

* chore: lint

* chore: check with linter

* chore: pass linter again

* chore: update comment

Co-authored-by: Ubaldo Santos <164866893+usantos-at-wiris@users.noreply.github.com>

* chore: update comment

Co-authored-by: Ubaldo Santos <164866893+usantos-at-wiris@users.noreply.github.com>

* chore: update comment

---------

Co-authored-by: Ubaldo Santos <164866893+usantos-at-wiris@users.noreply.github.com>
---
 classes/pluginwrapper.php                     | 12 +++++++++
 .../plugin/impl/TextServiceImpl.class.php     |  4 +--
 subfilters/php.php                            | 27 ++++++++++++++-----
 3 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/classes/pluginwrapper.php b/classes/pluginwrapper.php
index 13c0a73a..661dcb2c 100644
--- a/classes/pluginwrapper.php
+++ b/classes/pluginwrapper.php
@@ -208,6 +208,18 @@ public function was_chem_editor_enabled() {
         return $this->moodleconfig->waschemeditorenabled;
     }
 
+    /**
+     * Checks whether the LaTeX parsing feature is enabled.
+     *
+     * This method retrieves the configuration setting for LaTeX.
+     *
+     * @return bool True if LaTeX parsing is enabled, false otherwise.
+     */
+    public function wiris_editor_parse_latex() {
+        $value = $this->get_instance()->getConfiguration()->getProperty('wiriseditorparselatex', null);
+        return ($value == "true") ? true : false;
+    }
+
     /**
      * Returns MathType plugin data from the plugin installed in the default Moodle
      * HTML editor (or the first available), or false if none found.
diff --git a/integration/lib/com/wiris/plugin/impl/TextServiceImpl.class.php b/integration/lib/com/wiris/plugin/impl/TextServiceImpl.class.php
index f99cebfc..42be3b19 100644
--- a/integration/lib/com/wiris/plugin/impl/TextServiceImpl.class.php
+++ b/integration/lib/com/wiris/plugin/impl/TextServiceImpl.class.php
@@ -49,14 +49,14 @@ public function getMathML($digest, $latex) {
 		}
 	}
 	public function latex2mathml($latex) {
-		$param = array();;
+		$param = array();
 		$param["latex"] = $latex;
 		$provider = $this->plugin->newGenericParamsProvider($param);
 		$mathml = $this->service("latex2mathml", $provider);
 		return ((_hx_index_of($mathml, "Http Error #500", null) === -1) ? $mathml : "Error converting from latex to mathml");
 	}
 	public function mathml2latex($mml) {
-		$param = array();;
+		$param = array();
 		$param["mml"] = $mml;
 		$provider = $this->plugin->newGenericParamsProvider($param);
 		return $this->service("mathml2latex", $provider);
diff --git a/subfilters/php.php b/subfilters/php.php
index e123d8f3..cbce0abe 100644
--- a/subfilters/php.php
+++ b/subfilters/php.php
@@ -56,7 +56,12 @@ public function filter($text, array $options = []) {
         $n1 = stripos($text, '<math');
         $n2 = mb_stripos($text, '«applet');
 
-        if ($n0 === false && $n1 === false && $n2 === false) {
+        // Find LateX.
+        $matches = [];
+        $latexpattern = '/\$\$(.*?)\$\$/';
+        preg_match_all($latexpattern, $text, $matches);
+
+        if ($n0 === false && $n1 === false && $n2 === false && count($matches[0]) == 0) {
             // Nothing to do.
             return $text;
         }
@@ -66,12 +71,6 @@ public function filter($text, array $options = []) {
         // Automatic class loading not avaliable for Moodle 2.4 and 2.5.
         wrs_loadclasses();
 
-        // MathJax and MathML
-        // Not filter if MathJax filter order < MathType filter order.
-        if ($n1 !== false && $this->mathjax_have_preference()) {
-            return $text;
-        }
-
         $wirispluginwrapper = new filter_wiris_pluginwrapper();
 
         $wirispluginwrapper->begin();
@@ -89,6 +88,20 @@ public function filter($text, array $options = []) {
             $query .= 'category=' . $COURSE->category;
         }
 
+        // If MathJax doesn't have preference and wiriseditorparselatex = true, parse LateX into MathML.
+        if (!$this->mathjax_have_preference() && $wirispluginwrapper->wiris_editor_parse_latex()) {
+            foreach ($matches[0] as $latex) {
+                $response = $textservice->getMathML(null, $latex);
+
+                $decodedresponse = json_decode($response, true);
+                if (isset($decodedresponse['status']) && $decodedresponse['status'] === "ok") {
+                    $mathml = $decodedresponse['result']['text'];
+
+                    $text = str_replace($latex, $mathml, $text);
+                }
+            }
+        }
+
         $prop['refererquery'] = $query;
         $prop['lang'] = current_language();
         $prop['savemode'] = 'safeXml'; // ...safeXml filtering.