From 0ba561eb962f177793958c6c8478985d4bb5dde4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Erodis=20P=C3=A9rez=20Michel?=
 <EroPerez@users.noreply.github.com>
Date: Thu, 21 Oct 2021 14:46:34 -0400
Subject: [PATCH] Update Helper.php

Add support to get file content as base64 string to render in json object.
---
 src/phpSpreadsheet/Helper.php | 46 +++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/src/phpSpreadsheet/Helper.php b/src/phpSpreadsheet/Helper.php
index cf7163e..0ee1941 100644
--- a/src/phpSpreadsheet/Helper.php
+++ b/src/phpSpreadsheet/Helper.php
@@ -525,6 +525,41 @@ public static function save($filename='excel', $format='Xlsx')
         $objWriter->save($filepath);
         return $filepath;
     }
+    
+    /**
+     * Output file content to base64 uri string
+     * @param string $format
+     * @return string
+     *
+     * @throws \Exception
+     */
+    public static function getFileContent($format = 'Xlsx')
+    {
+        self::cleanOutput();
+
+        $objPhpSpreadsheet = self::validExcelObj();
+
+        // Create Writer first
+        $objWriter = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($objPhpSpreadsheet, $format);
+        $objWriter->setPreCalculateFormulas(true);
+
+        /**
+         * Type Mapping
+         */
+        $inTypeList = isset(self::$_writerTypeInfo[$format]);
+        $contentType = ($inTypeList) ? self::$_writerTypeInfo[$format]['contentType'] : '';
+
+        ob_start();
+        // Save file
+        $objWriter->save('php://output');
+        $content = ob_get_contents();
+        ob_clean();
+
+        $base64FileContent = base64_encode($content);
+
+        return "data:{$contentType};base64,{$base64FileContent}";
+    }
+
 
     /**
      * Get data of a row from the actived sheet of PhpSpreadsheet
@@ -863,4 +898,15 @@ private static function validSheetObj($sheetObj=NULL)
             throw new Exception("Invalid or empty PhpSpreadsheet Sheet Object", 400);
         }
     }
+    
+    /**
+     * This function discards the contents of the top most output buffer
+     * and turns off this output buffering.
+     */
+    private static function cleanOutput()
+    {
+        for ($level = ob_get_level(); $level > 0; --$level) {
+            @ob_end_clean();
+        }
+    }
 }