package and depencies

vendor/phpoffice/phpspreadsheet/README.md

@@ -11,6 +11,80 @@
 PhpSpreadsheet is a library written in pure PHP and offers a set of classes that
 allow you to read and write various spreadsheet file formats such as Excel and LibreOffice Calc.
 
+## PHP Version Support
+
+LTS: Support for PHP versions will only be maintained for a period of six months beyond the
+[end of life](https://www.php.net/supported-versions) of that PHP version.
+
+Currently the required PHP minimum version is PHP __7.4__, and we [will support that version](https://www.php.net/eol.php) until 28th June 2023.
+
+See the `composer.json` for other requirements.
+
+## Installation
+
+Use [composer](https://getcomposer.org) to install PhpSpreadsheet into your project:
+
+```sh
+composer require phpoffice/phpspreadsheet
+```
+
+If you are building your installation on a development machine that is on a different PHP version to the server where it will be deployed, or if your PHP CLI version is not the same as your run-time such as `php-fpm` or Apache's `mod_php`, then you might want to add the following to your `composer.json` before installing:
+```json
+{
+    "require": {
+        "phpoffice/phpspreadsheet": "^1.23"
+    },
+    "config": {
+        "platform": {
+            "php": "7.4"
+        }
+    }
+}
+```
+and then run
+```sh
+composer install
+```
+to ensure that the correct dependencies are retrieved to match your deployment environment.
+
+See [CLI vs Application run-time](https://php.watch/articles/composer-platform-check) for more details.
+
+### Additional Installation Options
+
+If you want to write to PDF, or to include Charts when you write to HTML or PDF, then you will need to install additional libraries:
+
+#### PDF
+
+For PDF Generation, you can install any of the following, and then configure PhpSpreadsheet to indicate which library you are going to use:
+ - mpdf/mpdf
+ - dompdf/dompdf
+ - tecnickcom/tcpdf
+
+and configure PhpSpreadsheet using:
+
+```php
+// Dompdf, Mpdf or Tcpdf (as appropriate)
+$className = \PhpOffice\PhpSpreadsheet\Writer\Pdf\Dompdf::class;
+IOFactory::registerWriter('Pdf', $className);
+```
+or the appropriate PDF Writer wrapper for the library that you have chosen to install.
+
+#### Chart Export
+
+For Chart export, we support following packages, which you will also need to install yourself using `composer require`
+ - [jpgraph/jpgraph](https://packagist.org/packages/jpgraph/jpgraph) (this package was abandoned at version 4.0. 
+   You can manually download the latest version that supports PHP 8 and above from [jpgraph.net](https://jpgraph.net/))
+ - [mitoteam/jpgraph](https://packagist.org/packages/mitoteam/jpgraph) (fork with php 8.1 support)
+
+and then configure PhpSpreadsheet using:
+```php
+Settings::setChartRenderer(\PhpOffice\PhpSpreadsheet\Chart\Renderer\JpGraph::class); // to use jpgraph/jpgraph
+//or
+Settings::setChartRenderer(\PhpOffice\PhpSpreadsheet\Chart\Renderer\MtJpGraphRenderer::class); // to use mitoteam/jpgraph
+```
+
+One or the other of these libraries is necessary if you want to generate HTML or PDF files that include charts.
+
 ## Documentation
 
 Read more about it, including install instructions, in the [official documentation](https://phpspreadsheet.readthedocs.io). Or check out the [API documentation](https://phpoffice.github.io/PhpSpreadsheet).