From 22eb55ddfe383318538b36d291c63a37d8b4d167 Mon Sep 17 00:00:00 2001
From: aVadim <vadim483@gmail.com>
Date: Fri, 12 Apr 2024 21:53:16 +0300
Subject: [PATCH] upd: save formulas with values

---
 docs/03-writing.md                    | 18 ++++++++++++++++++
 src/FastExcelWriter/Sheet.php         |  6 ++++--
 src/FastExcelWriter/Writer/Writer.php | 16 ++++++++++++----
 tests/FastExcelWriterTest.php         |  5 +++++
 4 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/docs/03-writing.md b/docs/03-writing.md
index 7442adc..54d9709 100644
--- a/docs/03-writing.md
+++ b/docs/03-writing.md
@@ -335,6 +335,24 @@ $sheet1->writeRow([120, 560]);
 $sheet1->writeRow([130, 117]);
 ```
 
+**Important!** The library cannot pre-calculate values of formulas. It save formulas as is, without pre-calculation.
+But when the saved file is opened in Excel, Excel recalculates all cells with formulas and show results.
+There's only one way to save pre-calculations: you do those calculations in your code and save them along with the formula
+```php
+$a1 = 10;
+$b1 = 30;
+$a2 = 50;
+$b2 = 70;
+$sheet->writeRow([$a1, $b1]);
+$sheet->writeRow([$a2, $b2]);
+
+// formula and pre-calculated result
+$a3 = ['=A1+A2', $a1 + $a2];
+$b3 = ['=B1+B2', $b1 + $b2];
+$sheet->writeRow([$a3, $b3]);
+```
+
+
 ### Hyperlinks
 You can insert URLs as active hyperlinks
 
diff --git a/src/FastExcelWriter/Sheet.php b/src/FastExcelWriter/Sheet.php
index fc67673..c12b7b3 100644
--- a/src/FastExcelWriter/Sheet.php
+++ b/src/FastExcelWriter/Sheet.php
@@ -2311,7 +2311,10 @@ protected function _setCellData($cellAddress, $value, $styles = null, ?bool $mer
         }
 
         if ($value !== null) {
-            if (!is_scalar($value)) {
+            if (is_array($value) && !empty($value[0]) && is_string($value[0]) && ($value[0][0] === '=') && count($value) === 2) {
+                // it's a formula & value ['=A1+B2', 123]
+            }
+            elseif (!is_scalar($value)) {
                 $addr = Excel::cellAddress($colIdx + 1, $rowIdx + 1);
                 Exception::throwNew('Value for cell %s must be scalar', $addr);
             }
@@ -2377,7 +2380,6 @@ public function setFormula($cellAddress, $value, array $styles = null): Sheet
             $value = '=' . $value;
         }
 
-        ///-- $styles = $styles ? Style::normalize($styles) : null;
         $this->_setCellData($cellAddress, $value, $styles, true);
 
         return $this;
diff --git a/src/FastExcelWriter/Writer/Writer.php b/src/FastExcelWriter/Writer/Writer.php
index c52a6e3..4689296 100644
--- a/src/FastExcelWriter/Writer/Writer.php
+++ b/src/FastExcelWriter/Writer/Writer.php
@@ -1200,14 +1200,22 @@ public function _writeCell(FileWriter $file, int $rowNumber, int $colNumber, $va
         if (is_array($value) && isset($value['shared_index'])) {
             $file->write('<c r="' . $cellName . '" s="' . $cellStyleIdx . '" t="s"><v>' . $value['shared_index'] . '</v></c>');
         }
-        elseif (!is_scalar($value) || $value === '') { //objects, array, empty; null is not scalar
-            $file->write('<c r="' . $cellName . '" s="' . $cellStyleIdx . '"/>');
-        }
-        elseif (is_string($value) && $value[0] === '=') {
+        elseif ($value && is_string($value) && $value[0] === '=') {
             // formula
             $value = $this->_convertFormula($value, [$rowNumber, $colNumber]);
             $file->write('<c r="' . $cellName . '" s="' . $cellStyleIdx . '"><f>' . self::xmlSpecialChars($value) . '</f></c>');
         }
+        elseif (is_array($value) && !empty($value[0]) && $value[0][0] === '=' && isset($value[1])) {
+            // formula & value
+            $formula = $this->_convertFormula($value[0], [$rowNumber, $colNumber]);
+            $file->write('<c r="' . $cellName . '" s="' . $cellStyleIdx . '">');
+            $file->write('<f>' . self::xmlSpecialChars($formula) . '</f>');
+            $file->write('<v>' . self::xmlSpecialChars($value[1]) . '</v>');
+            $file->write('</c>');
+        }
+        elseif (!is_scalar($value) || $value === '') { //objects, array, empty; null is not scalar
+            $file->write('<c r="' . $cellName . '" s="' . $cellStyleIdx . '"/>');
+        }
         elseif ($numFormatType === 'n_shared_string') {
             $file->write('<c r="' . $cellName . '" s="' . $cellStyleIdx . '" t="s"><v>' . $value . '</v></c>');
         }
diff --git a/tests/FastExcelWriterTest.php b/tests/FastExcelWriterTest.php
index 9210429..e335337 100644
--- a/tests/FastExcelWriterTest.php
+++ b/tests/FastExcelWriterTest.php
@@ -536,6 +536,7 @@ public function testExcelWriter4()
         $data = [
             [2, 2, '=RC[-1]+RC[-2]', 2],
             [3, 3, '=RC[-1]+RC[-2]', 3],
+            [4, 4, ['=RC[-1]+RC[-2]', 8], 4], // formula & value
         ];
         $area = $sheet->beginArea('b2');
         $area->moveTo('c3');
@@ -549,6 +550,10 @@ public function testExcelWriter4()
 
         $this->assertEquals([1, 1, '=D3+C3', '1'], $this->getValues(['c3', 'd3', 'e3', 'f3']));
 
+        // formula & value
+        $this->assertEquals(8, $this->cells[6]['E']['v']);
+        $this->assertEquals('=D6+C6', $this->cells[6]['E']['f']);
+
         $style = $this->getStyle('c3', true);
         $this->assertEquals('21', $style['font-size']);
         $this->assertEquals('Century', $style['font-name']);