File Uploads Using HTML Forms

In Chapter 6, Forms, we learned about HTML forms. We discussed how to use the method attribute of <form> for GET or POST requests. Though we have only submitted text data using a form so far, it is also possible to submit one or more files using a form.

When submitting files, we must ensure that there are at least two attributes on the form: method and enctype. You may still also need other attributes, such as action. A form that supports file uploads might look like this:

<form method="post" enctype="multipart/form-data">

File uploads are only available for POST requests. They are not possible with GET requests as it would be impossible to send all the data for a file through a URL. The enctype attribute must be set to let the browser know it should send the form data as multiple parts, one part for the text data of the form, and separate parts for each of the files that have been attached to the form. This encoding...