e2pdf / classes / helper / e2pdf-math.php

e2pdf-math.php in E2Pdf – Export Pdf Tool for WordPress 1.32.49, at classes/helper/e2pdf-math.php

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1	<?php
2
3	/**
4	* File: /helper/e2pdf-math.php
5	*
6	* @package E2Pdf
7	* @license GPLv3
8	* @link https://e2pdf.com
9	*/
10	if (!defined('ABSPATH')) {
11	die('Access denied.');
12	}
13
14	/** @license
15	* Based on https://gist.github.com/ircmaxell/1232629
16	*/
17	class Helper_E2pdf_Math {
18
19	private $helper;
20	protected $variables = [];
21	protected $stack = [];
22	protected $output = [];
23
24	public function __construct() {
25	$this->helper = Helper_E2pdf_Helper::instance();
26	}
27
28	public function pre_render($value = '', $extension = null) {
29	$replacements = [];
30	if ($value) {
31	preg_match_all('@\[([^<>&/\[\]\x00-\x20=]++)@', $value, $matches);
32	$tagnames = $matches[1];
33	if (!empty($tagnames)) {
34	preg_match_all('/' . $this->helper->load('shortcode')->get_shortcode_regex($tagnames) . '/', $value, $shortcodes);
35	foreach ($shortcodes[0] as $key => $shortcode_value) {
36	$index = count($replacements) + 1;
37	$replacements[] = $shortcode_value;
38	$value = str_replace($shortcode_value, '%' . $index . '$s', $value);
39	}
40	}
41
42	if (method_exists($extension, 'strip_math')) {
43	$value = $extension->strip_math($value, $replacements);
44	}
45
46	if (!empty($replacements)) {
47	$value = preg_replace('/%(?!\d+\$s)/', '%%', $value);
48	$value = vsprintf(
49	$value, array_map(
50	function ($v) {
51	return '(' . $v . ')';
52	}, $replacements
53	)
54	);
55	}
56	}
57	return $value;
58	}
59
60	public function after_render($value) {
61	return str_replace('()', '0', $value);
62	}
63
64	public function evaluate($string) {
65	try {
66	$this->stack = $this->parse($string);
67	return $this->run();
68	} catch (Exception $ex) {
69	return $ex->getMessage();
70	}
71	}
72
73	public function parse($string) {
74	$tokens = $this->tokenize(str_replace(' ', '', $string));
75	$this->output = [];
76	$this->operators = [];
77	foreach ($tokens as $token) {
78	$token = $this->extractVariables($token);
79	$expression = $this->factory($token);
80	if ($expression->operator) {
81	$this->parseOperator($expression);
82	} elseif (isset($expression->type) && $expression->type == 'parenthesis') {
83	$this->parseParenthesis($expression);
84	} else {
85	$this->output[] = $expression;
86	}
87	}
88	// phpcs:ignore WordPress.CodeAnalysis.AssignmentInCondition.FoundInWhileCondition
89	while (($op = array_pop($this->operators))) {
90	if (isset($op->type) && $op->type == 'parenthesis') {
91	throw new Exception(__('Mismatched Parenthesis in Math operation', 'e2pdf'));
92	}
93	$this->output[] = $op;
94	}
95	return $this->output;
96	}
97
98	public function registerVariable($name, $value) {
99	$this->variables[$name] = $value;
100	}
101
102	public function run() {
103	// phpcs:ignore WordPress.CodeAnalysis.AssignmentInCondition.FoundInWhileCondition
104	while (($operator = array_pop($this->stack)) && $operator->operator) {
105	$value = $this->operate($operator);
106	if (!is_null($value)) {
107	$this->stack[] = $this->factory($value);
108	}
109	}
110	return $operator ? $operator->value : $this->render();
111	}
112
113	protected function extractVariables($token) {
114	if ($token[0] == '$') {
115	$key = substr($token, 1);
116	return isset($this->variables[$key]) ? $this->variables[$key] : 0;
117	}
118	return $token;
119	}
120
121	protected function render() {
122	$output = '';
123	// phpcs:ignore WordPress.CodeAnalysis.AssignmentInCondition.FoundInWhileCondition
124	while (($el = array_pop($this->stack))) {
125	$output .= $el->value;
126	}
127	if ($output) {
128	return $output;
129	}
130	throw new Exception(__('Could not parse Math operation', 'e2pdf'));
131	}
132
133	protected function parseParenthesis($expression) {
134	if ($expression->open) {
135	$this->operators[] = $expression;
136	} else {
137	$clean = false;
138	// phpcs:ignore WordPress.CodeAnalysis.AssignmentInCondition.FoundInWhileCondition
139	while (($end = array_pop($this->operators))) {
140	if (isset($end->type) && $end->type == 'parenthesis') {
141	$clean = true;
142	break;
143	} else {
144	$this->output[] = $end;
145	}
146	}
147	if (!$clean) {
148	throw new Exception(__('Mismatched Parenthesis in Math operation', 'e2pdf'));
149	}
150	}
151	}
152
153	protected function parseOperator($expression) {
154	$end = end($this->operators);
155	if (!$end) {
156	$this->operators[] = $expression;
157	} elseif ($end->operator) {
158	do {
159	if ($expression->operator && $expression->precidence <= $end->precidence) {
160	$this->output[] = array_pop($this->operators);
161	} elseif (!$expression->operator && $expression->precidence < $end->precidence) {
162	$this->output[] = array_pop($this->operators);
163	} else {
164	break;
165	}
166	} while (($end = end($this->operators)) && $end->operator); // phpcs:ignore WordPress.CodeAnalysis.AssignmentInCondition.FoundInWhileCondition
167
168	$this->operators[] = $expression;
169	} else {
170	$this->operators[] = $expression;
171	}
172	}
173
174	protected function tokenize($string) {
175	$parts = preg_split('((\b\d[\d.]\b\|\+\|-\|$\|$\|\\|\^\|¦\|/)\|\s+)', $string, null, PREG_SPLIT_NO_EMPTY \| PREG_SPLIT_DELIM_CAPTURE);
176	$parts = array_map('trim', $parts);
177
178	$tokens = [];
179	$expectOperand = true;
180
181	$count = count($parts);
182	for ($i = 0; $i < $count; $i++) {
183	$token = $parts[$i];
184	if (($token === '+' \|\| $token === '-') && $expectOperand) {
185	$sign = 1;
186	while ($i < $count && ($parts[$i] === '+' \|\| $parts[$i] === '-')) {
187	if ($parts[$i] === '-') {
188	$sign *= -1;
189	}
190	$i++;
191	}
192	if ($i >= $count \|\| $parts[$i] === ')') {
193	if (!empty($tokens)) {
194	$last = end($tokens);
195	if (in_array($last, ['+', '-', '*', '/', '^', '¦'], true)) {
196	array_pop($tokens);
197	}
198	}
199	if ($i < $count) {
200	$i--;
201	}
202	$expectOperand = false;
203	continue;
204	}
205	$next = $parts[$i];
206	if (is_numeric($next)) {
207	$tokens[] = ($sign === -1) ? (string) (-1 * floatval($next)) : $next;
208	$expectOperand = false;
209	} elseif ($next === '(') {
210	if ($sign === -1) {
211	$tokens[] = '-1';
212	$tokens[] = '*';
213	}
214	$tokens[] = '(';
215	$expectOperand = true;
216	} else {
217	$tokens[] = $next;
218	$expectOperand = false;
219	}
220	} elseif ($token === '(') {
221	$tokens[] = $token;
222	$expectOperand = true;
223	} elseif ($token === ')') {
224	$tokens[] = $token;
225	$expectOperand = false;
226	} elseif (in_array($token, ['+', '-', '*', '/', '^', '¦'], true)) {
227	$tokens[] = $token;
228	$expectOperand = true;
229	} else {
230	$tokens[] = $token;
231	$expectOperand = false;
232	}
233	}
234	return $tokens;
235	}
236
237	protected function factory($value) {
238	$expression = new stdClass();
239	$expression->open = false;
240	$expression->operator = false;
241	$expression->precidence = 0;
242	$expression->type = 'expression';
243	if (is_object($value)) {
244	return $value;
245	} elseif (is_numeric($value)) {
246	$expression->type = 'number';
247	} elseif ($value == '+') {
248	$expression->operator = true;
249	$expression->type = 'addition';
250	$expression->precidence = 4;
251	} elseif ($value == '-') {
252	$expression->operator = true;
253	$expression->type = 'subtraction';
254	$expression->precidence = 4;
255	} elseif ($value == '*') {
256	$expression->operator = true;
257	$expression->type = 'multiplication';
258	$expression->precidence = 5;
259	} elseif ($value === '¦') {
260	$expression->operator = true;
261	$expression->type = 'modulus';
262	$expression->precidence = 5;
263	} elseif ($value == '/') {
264	$expression->operator = true;
265	$expression->type = 'division';
266	$expression->precidence = 5;
267	} elseif ($value == '^') {
268	$expression->operator = true;
269	$expression->type = 'power';
270	$expression->precidence = 6;
271	} elseif (in_array($value, ['(', ')'], true)) {
272	$expression->type = 'parenthesis';
273	$expression->precidence = 7;
274	$expression->open = $value == '(';
275	} else {
276	$value = 0;
277	$expression->type = 'number';
278	}
279	$expression->value = $value;
280	return $expression;
281	}
282
283	protected function operate($expression) {
284	$value = null;
285	if (isset($expression->type)) {
286	switch ($expression->type) {
287	case 'number':
288	$value = $expression->value;
289	break;
290	case 'addition':
291	$value = $this->operate(array_pop($this->stack)) + $this->operate(array_pop($this->stack));
292	break;
293	case 'subtraction':
294	$left = $this->operate(array_pop($this->stack));
295	$right = $this->operate(array_pop($this->stack));
296	$value = $right - $left;
297	break;
298	case 'multiplication':
299	$value = $this->operate(array_pop($this->stack)) * $this->operate(array_pop($this->stack));
300	break;
301	case 'division':
302	$left = $this->operate(array_pop($this->stack));
303	$right = $this->operate(array_pop($this->stack));
304	$value = ($left == 0) ? 0 : $right / $left;
305	break;
306	case 'power':
307	$left = $this->operate(array_pop($this->stack));
308	$right = $this->operate(array_pop($this->stack));
309	$value = pow($right, $left);
310	break;
311	case 'modulus':
312	$left = $this->operate(array_pop($this->stack));
313	$right = $this->operate(array_pop($this->stack));
314	$value = ($left == 0) ? 0 : ($right % $left);
315	break;
316	default:
317	break;
318	}
319	}
320	return $value;
321	}
322	}
323