Initial commit

2023-11-25 14:54:50 +01:00 · 2023-11-25 14:54:50 +01:00 · b9078dcf5b
commit b9078dcf5b
parent 9abe18f886
1 changed files with 126 additions and 0 deletions
--- a/TextformatterLatexMathML.module
+++ b/TextformatterLatexMathML.module
@ -0,0 +1,126 @@
+<?php 
+/*
+  Copyright (C) 2023 by 7u83 7u83@mail.ru
+
+  Permission to use, copy, modify, and/or distribute this software 
+  for any purpose with or without fee is hereby granted.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL 
+  WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED 
+  WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE 
+  AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 
+  DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, 
+  DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR 
+  OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE 
+*/
+
+namespace ProcessWire;
+
+class TextFormatterLatexMathML extends Textformatter {
+
+	public static function getModuleInfo() {
+
+	        return array(
+			'title' => 'LatexMathML Text Formatter',
+			'version' => '1.0.0',
+			'summary' => 'Replaces $latexformula$ with inline MathML',
+			'author' = '7u83',
+			'autoload' => true,
+			'singular' => true,
+			'href' => 'https://git.planix.org/7u83/processwire-TextformatterLatexMathML',
+			'requires' => array('ProcessWire>=3.0.0'),
+		);
+    	}
+
+	public function format(&$str) {
+
+		// Regular expression to match LaTeX formulas within $ symbols
+		$latexPattern = '/(?<!\\\\)\$([^$\\\\]*(\\\\.[^$\\\\]*)*)\$/';
+
+		$inputString = $str;
+
+		// Create a DOMDocument object
+		$dom = new \DOMDocument('1.0', 'UTF-8');
+
+		// Load the HTML string into the DOMDocument
+		$dom->loadHTML('<?xml encoding="utf-8" ?><html>'.$inputString.'</html>', LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);
+
+		// Create a DOMXPath object to navigate the DOMDocument
+		$xpath = new \DOMXPath($dom);
+
+		// Find all <p>, <div>, <span> ... elements
+		$elements = $xpath->query('//p | //div | //span | //strong | //b | //i | //em');
+
+
+		$nodesForReplacement = array();
+
+		// Iterate through the elements and create and arraz of nodes to modify
+		foreach ($elements as $element) {
+			foreach ($element->childNodes as $node) {
+				if ($node->nodeType === XML_TEXT_NODE) {
+
+					// convert $formula$ to mathml
+					$modifiedValue = preg_replace_callback($latexPattern, array($this,'convertToMathML'), $node->nodeValue);
+
+					// unescape esaped $-signs
+					$modifiedValue = str_replace('\$', '$',$modifiedValue);
+
+					// Save the node and its modified content for later replacement
+           				 $nodesForReplacement[] = array(
+				                'node' => $node,
+				                'modifiedValue' => $modifiedValue
+					);
+				}
+			}
+
+		}
+
+		// Replace the nodes 
+		foreach ($nodesForReplacement as $replacement) {
+			$fragment = $dom->createDocumentFragment();
+			$fragment->appendXML($replacement['modifiedValue']);
+			$replacement['node']->parentNode->replaceChild($fragment, $replacement['node']);
+		}
+
+
+		// Output the modified HTML
+		$str = str_replace(array('<html>','</html>') , '' , $dom->saveHTML($dom->documentElement));
+	}
+
+	// Define a callback function to convert the matched formula to MathML
+	function convertToMathML($matches) {
+		$cache = wire('cache');
+
+		// $matches[1] contains the matched substring within '$'
+		$formula = $matches[1];
+
+		$cn = "TFLatexMathML$formula";
+		$mathml = base64_decode($cache->get($cn));
+		if ($mathml)
+			return $mathml;
+
+		$mathml = $this->convertFormulaToMathML($formula);
+		$cache->save($cn,base64_encode($mathml));
+
+		// Return the processed result as the replacement
+		return $mathml;
+	}
+
+	// Function to convert a formula to MathML
+	function convertFormulaToMathML($formula) {
+
+		$command = 'latexmlmath --quiet -';
+		$inputString = '$'.$formula.'$';
+
+
+		// Construct the full command with the input string
+		$fullCommand = sprintf('echo %s | %s', escapeshellarg($inputString), $command);
+
+
+		// Execute the command and capture the output
+		$output = shell_exec($fullCommand);
+
+		return $output;
+	}
+}
+