TIL: button elements offer attributes to change form behavior

Today, I was reading A Complete Guide to Links and Buttons written by Chris Coyier. button and a elements are often misused. To help out, Chris' article gives a good overview of their functionalities and best practices.

One section about button attributes caught my eye. In it, Chris lists the attributes one could use with a button element.

The following attributes were new to me:

• formaction
• formenctype
• formmethod
• formnovalidate

It turns out, that you can use these to overwrite the behavior of an associated form.

Let's have a look at an example.

<form action="/some-endpoint" method="post">
  <label>
    Your name
    <input name="full-name" type="text" required>
  </label>
  <button 
    formaction="/some-other-endpoint"
    formmethod="get"
    formnovalidate>Submit</button>
</form>

The initial configuration of this form leads to a POST request made to /some-endpoint. Also, the form should only be submitable when the full-name input holds a value.

This configuration is overwritten by the submit button though. 😲

If you hit the submit button (or press ENTER inside of the input field), there is no input value validation anymore (formnovalidate). The made request is a GET request (formmethod) going to /some-other-endpoint (formaction).

You might not need these "overwrite-attributes" very often, but when you do, I bet they're life-savers!

You can read more about these attributes on MDN, or you can have a look at the above form example on CodePen.