Refactor wp-login.php

[westi]

wp-login.php has a lot of code in it's case statement and it would be good to refactor it so that the different actions are handled by functions.

[santosj]

Dude. You've totally read my mind.

There have been a couple of times where I'm all like, "Damn it, I'm doing this, I'm refactoring this mess!"

Then looking through everything, I realize it isn't that bad and while there are somethings that would better be in a function, a lot of the code is presentation and can't easily be placed in a function or I can't think of a reason.

However, where I was coming from was refactoring the current stuff, the viewpoint might be to add in additional features or something.

[ryan]

Patch moves the POST handling code into functions, making the template-y bits easier to read. retrieve_password(), reset_password(), and register_new_user() are defined at the top of the file. All of them return WP_Error objects in the event of an error. wp_signon() is defined in user.php and is meant to be reusable. The logout code moved into a wp_logout() pluggable function. wp_login() is deprecated in favor of the new wp_authenticate() function which returns a WP_Error object rather than setting an $error global.

[ryan]

(In [6643]) Refactor login. see #5405

[darkdragon]

Yeah. Hmm.

I probably should have suggested a couple of things earlier, but I'll just make a patch instead.

[darkdragon]

I will say that it is awesomely sweet and the suggestions are minor.

[ryan]

(In [6644]) Pass remember arg. see #5405

[ryan]

Urg, stuff for #5439 slipped in. Only the user.php change is pertinent.

[afercia]

In 44918:

Accessibility: Login: Display error messages when both the username and password fields are empty.

For accessibility and usability, if an input error is detected, the item that is in error needs to be identified and the error needs to be described to the user in text (WCAG Success Criterion 3.3.1). The login form displays an error when the username field is empty or when the password field is empty. It omits to do so when both fields are empty.

This change restores the login form behavior to the one that used to work in WordPress 2.3 (!) and displays the related error messages also when both fields are empty.

Props birgire, audrasjb.
See #8938, #5405, #3708.
Fixes #42985.