Xlsx Reader and Print/Show Gridlines

Fix #912, opened in Feb. 2019, and closed as stale in Apr. 2019, and which I have re-opened to be closed properly by this PR. Another "better late than never". Original issue says that print options should not affect ShowGridlines, which seems true enough. Aside from that, the existing code isn't quite correct anyhow. Excel looks for 2 attributes, one of which must be explicitly set to true and the other of which must not be explicitly set to false, in order to determine whether PrintGridlines should be set. PhpSpreadsheet is changed to do the same. This could be treated as a BC break for the unusual situation described in the issue, but it seems more like a bug fix to me.

Author: oleibman

src/PhpSpreadsheet/Reader/Xlsx/SheetViewOptions.php

@@ -122,11 +122,12 @@ private function sheetFormat(SimpleXMLElement $sheetFormatPrx): void
     private function printOptions(SimpleXMLElement $printOptionsx): void
     {
         $printOptions = $printOptionsx->attributes() ?? [];
-        if (isset($printOptions['gridLinesSet']) && self::boolean((string) $printOptions['gridLinesSet'])) {
-            $this->worksheet->setShowGridlines(true);
-        }
+        // Spec is weird. gridLines (default false)
+        // and gridLinesSet (default true) must both be true.
         if (isset($printOptions['gridLines']) && self::boolean((string) $printOptions['gridLines'])) {
-            $this->worksheet->setPrintGridlines(true);
+            if (!isset($printOptions['gridLinesSet']) || self::boolean((string) $printOptions['gridLinesSet'])) {
+                $this->worksheet->setPrintGridlines(true);
+            }
         }
         if (isset($printOptions['horizontalCentered']) && self::boolean((string) $printOptions['horizontalCentered'])) {
             $this->worksheet->getPageSetup()->setHorizontalCentered(true);

tests/PhpSpreadsheetTests/Reader/Xlsx/GridlinesTest.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpOffice\PhpSpreadsheetTests\Reader\Xlsx;
+
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheetTests\Functional\AbstractFunctional;
+
+class GridlinesTest extends AbstractFunctional
+{
+    /**
+     * @dataProvider loadDataProvider
+     */
+    public function testGridlines(bool $display, bool $print): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet1 = $spreadsheet->getActiveSheet();
+        $sheet2 = $spreadsheet->createSheet();
+        $sheet1->setShowGridlines($display);
+        $sheet1->setPrintGridlines($print);
+        $sheet1->fromArray(
+            [
+                [1, 2, 3],
+                [4, 5, 6],
+                [7, 8, 9],
+            ]
+        );
+        $reloadedSpreadsheet = $this->writeAndReload($spreadsheet, 'Xlsx');
+        $spreadsheet->disconnectWorksheets();
+        $rsheet1 = $reloadedSpreadsheet->getSheet(0);
+        $rsheet2 = $reloadedSpreadsheet->getSheet(1);
+        self::assertSame($display, $rsheet1->getShowGridlines());
+        self::assertSame($print, $rsheet1->getPrintGridlines());
+        self::assertTrue($rsheet2->getShowGridlines());
+        self::assertFalse($rsheet2->getPrintGridlines());
+        $reloadedSpreadsheet->disconnectWorksheets();
+    }
+
+    public static function loadDataProvider(): array
+    {
+        return [
+            [true, true],
+            [true, false],
+            [false, true],
+            [false, false],
+        ];
+    }
+}