Is action really required on forms?

Question

Here it says it's required

http://www.w3schools.com/tags/att_form_action.asp

but I see that forms get submitted even if I don't specify an action attribute, and the form gets submitted to the current page which is exactly what I want.

Answer 1

The requirement is only by standards. It is perfectly possible to do whatever you want on a page and not follow standards. Things may not display or work correctly if you do that, but likely they will. The goal is to follow them, and the idea is that if you follow them, your page will always work; you don't have to worry about anything.

Yes, the form is required to have an action attribute in HTML4. If it's not set, the browser will likely use the same method as providing an empty string to it. You really should set action="" which is perfectly valid HTML4, follows standards, and achieves the same exact result.

In HTML5, you can actually specify an action on the submit button itself. If there isn't one, it uses the form's action and if that is not set, it defaults to the empty string (note you cannot explicitly set the action to an empty string in HTML5).

Answer 2

It looks like the HTML4 spec requires it. I suspect some browsers do what you want to "make things easier". I don't recommend relying it on though. Since you're in undefined behavior, a browser could reasonably decide to just do nothing when the form is submitted with no action.

You can get the behavior you want while following the spec by leaving the action blank (since it's relative, blank means the current page):

<form action="" ...>

As mentioned by bazmegakapa, the HTML5 spec doesn't seem to require the action attribute:

The action and formaction content attributes, if specified, must have a value that is a valid non-empty URL potentially surrounded by spaces.[emphasis added]

Interestingly, this means in HTML5, <form action=""> is not valid, but it's not clear if a form without an action is required to work (submit to the current page).

Answer 3

Technically it's a violation of the HTML 4 spec, but all browsers will post back to the originator of the response if no action is specified. I would agree it's not a smart idea to rely on it but it does work.

EDIT: As it has been pointed out to me that this question is tagged as HTML 5: In HTML 5 they list the action attribute as no longer required: http://www.w3schools.com/html5/att_form_action.asp which is in accordance with the HTML 5 specs.

Answer 4

// thread resurrection alert

To extend upon animuson's answer...

If after all button formaction and form action attributes have been assessed, if "action" still evaluates as "empty string", then from HTML5.2 spec section 4.10.21.3 point 8 states:

If action is the empty string, let action be the document’s URL of the form document.

when it comes to submission of the form, which is what you wanted.