Both installation php and phpspreadsheet is outside of this video scope. While the purpose is to import data from spreadsheet, which sould be uploaded to the server, We skip the upload process. It simplify the process and we can only focus on extracting the datum from the speadsheet file. We want to aply DRY principle, hence we will create CodeIgniter helper (a php file which contain reusable function).
It's good if we can also focus on WIP See range cell doc