I'm a beginner web developer, and I'm coding a small project, mostly in order to learn the practice.
I am now writing an HTML page (with JavaScript) that collects data from users. The HTML page is pretty complicated and by the time a user had finished filling all the fields, not all the data is in the form - some of it was calculated by JavaScript and stored, either in localstorage or in attributes of certain HTML elements.
How can I submit the data into a MySQL database? (using methods with POST in PHP, like this one, only allows to send data that is in <input> tags)
 
     
     
    