Make Class Extendable

Document some cases where solution might not work well. Making class extendable and offering some over-rideable methods may allow for solutions to some of these problems.

Author: oleibman

docs/topics/reading-and-writing-to-file.md

@@ -1200,7 +1200,12 @@ You can then echo `$result` to a terminal, or write it to a file with `file_put_
     | A   | B                | C | D        |
 +---+-----+------------------+---+----------+
 | 1 | 6   | 1900-01-06 00:00 |   | 0.572917 |
-| 2 | 6   | 1900-01-06 00:00 |   | 1<>2     |
+| 2 | 6   | TRUE             |   | 1<>2     |
 | 3 | xyz | xyz              |   |          |
 +---+-----+------------------+---+----------+
 ```
+Please note that this may produce sub-optimal results for situations such as:
+- use of accents as combining characters rather than using pre-composed characters (may be handled by extending the class to override the `getString` or `strlen` methods)
+- Fullwidth characters
+- right-to-left characters (better display in a browser than a terminal on a non-RTL system)
+- multi-line strings

src/PhpSpreadsheet/Helper/TextGrid.php

@@ -48,7 +48,7 @@ public function render(): string
 
         if (!empty($this->rows)) {
             $maxRow = max($this->rows);
-            $maxRowLength = mb_strlen((string) $maxRow) + 1;
+            $maxRowLength = strlen((string) $maxRow) + 1;
             $columnWidths = $this->getColumnWidths();
 
             $this->renderColumnHeader($maxRowLength, $columnWidths);
@@ -80,10 +80,10 @@ private function renderRows(int $maxRowLength, array $columnWidths): void
     private function renderCells(array $rowData, array $columnWidths): void
     {
         foreach ($rowData as $column => $cell) {
-            $valueForLength = StringHelper::convertToString($cell, convertBool: true);
+            $valueForLength = $this->getString($cell);
             $displayCell = $this->isCli ? $valueForLength : htmlentities($valueForLength);
             $this->gridDisplay .= '| ';
-            $this->gridDisplay .= $displayCell . str_repeat(' ', $columnWidths[$column] - mb_strlen($valueForLength) + 1);
+            $this->gridDisplay .= $displayCell . str_repeat(' ', $columnWidths[$column] - $this->strlen($valueForLength) + 1);
         }
     }
 
@@ -95,7 +95,7 @@ private function renderColumnHeader(int $maxRowLength, array &$columnWidths): vo
             return;
         }
         foreach ($this->columns as $column => $reference) {
-            $columnWidths[$column] = max($columnWidths[$column], mb_strlen($reference));
+            $columnWidths[$column] = max($columnWidths[$column], $this->strlen($reference));
         }
         if ($this->rowHeaders) {
             $this->gridDisplay .= str_repeat(' ', $maxRowLength + 2);
@@ -145,9 +145,19 @@ private function getColumnWidth(array $columnData): int
         $columnData = array_values($columnData);
 
         foreach ($columnData as $columnValue) {
-            $columnWidth = max($columnWidth, mb_strlen(StringHelper::convertToString($columnValue, convertBool: true)));
+            $columnWidth = max($columnWidth, $this->strlen($this->getString($columnValue)));
         }
 
         return $columnWidth;
     }
+
+    protected function getString(mixed $value): string
+    {
+        return StringHelper::convertToString($value, convertBool: true);
+    }
+
+    protected function strlen(string $value): int
+    {
+        return mb_strlen($value);
+    }
 }