access html 5 data attribute in php

Question

I have a form which includes

<input id="user-id" type="text" data-user-id="" name="message" placeholder="type and send..." class="form-control">

data-user-id HTML5 data attribute. When I submit the form, I want to use the value of data attribute in a php class. How to access this data attribute in php?

Answer 1

Your user ID should be in a separate hidden field, such as:

<input type="hidden" name="user_id" value="123">
<input type="text" name="message" placeholder="type and send..." class="form-control">

Your message input shouldn't have an id of user-id and shouldn't need data-user-id at all.

Data attributes are used by JavaScript. Hidden inputs pass values to PHP that the user doesn't need to see. Neither are truly hidden to the user.