Add hooks before output for each action in wp-login.php

[jfarthing84]

7 years ago, in #9682, wp-login.php was made more pluggable. The thing is, if you just want to change the look (as my plugin "Theme My Login" does), you also have to replicate the logic.

Having an action that fires just before the login_header() call in each case of the action handler switch should be sufficient. One such hook is already present for one action: lost_password.

However, the hook register is already in use for the register link as is the format {$action}_form. So, I propose using pre_{$action}_form.

Patch incoming.

[voldemortensen]

38079.patch​ looks good to me, the @since docs will need to be updated though.

[dingo_bastard]

While I agree that this is cool thing to have, ​login_header function already has a lot of filters and action hooks that you can use to modify how the login form looks. So you can easily use login_header action for instance to place something before logo in the login form.
There is also login_messages filter that you can use to modify the login messages.

It would be better to place actions inside the login_header function, you could also filter them based on the error message.

[dingo_bastard]

Added action hooks inside login_header function

[jbpaul17]

Punting to 4.8.1 per today's bug scrub.

[jbpaul17]

Per today's bug scrub, we'll punt this as the focus for 4.8.1 is regressions only.

[voldemortensen]

38079.patch​ still applies cleanly, @since docs just need to be updated.

[SergeyBiryukov]

I agree with @dingo_bastard that existing hooks in login_header() can be used to customize the login page, so I don't see how 38079.patch​ would make it more customizable.

38079.2.patch​ makes more sense to me, but I'd like know a use case for these new actions that cannot be achieved with existing hooks.

[SergeyBiryukov]

On second thought, hooks before any output might indeed be helpful for redirects or more extensive customizations.

Perhaps they need better names though. pre_lostpassword_form sounds like it fires after the header and right before the form, not before any output on the page.

If the goal is to short-circuit login_header(), maybe pre_login_header should be added instead.

[SergeyBiryukov]

There's a ​login_form_{$action} dynamic hook, so maybe pre_login_form_{$action}_header would be a better name for these new hooks from 38079.patch​, which would expand to:

• pre_login_form_lostpassword_header
• pre_login_form_resetpass_header
• pre_login_form_register_header
• pre_login_form_login_header

[dingo_bastard]

The do_action hooks I added could be proven useful to add some additional messages (I think I was working for a client 6 months ago, and I could have benefitted from such hooks).

[hellofromTonya]

The request is to add a hook _before_ each action's output (i.e. the HTML sent out to the browser).

Having an action that fires just before the login_header() call in each case of the action handler switch should be sufficient.

Why doesn't 38079.patch​ cover all of the actions? It's adding 5 pre hooks. But there are 9 output points for the actions and each of those invokes login_header(). Looking at the switch ( $action ) cases:

• 1x in 'confirm_admin_email' action.
• 1x in the 'lostpassword' and 'retrievepassword' actions.
• 2x in the 'resetpass' and 'rp' actions.
• 1x in the 'register' action.
• 1x in the 'checkmail' action.
• 1x in the 'confirmaction' action.
• 2x in the 'login' and default actions.

These actions do not output HTML:

• 'postpass'
• 'logout'

Notice: login_header() is invoked 9 times and there 9 paths for the actions that output HTML.

So I'm wondering ... instead of adding individual do_action() just before each login_header() instance, why not add just one do_action() at the start of function itself?

There are a fews of ways to do this:

Option 1: The new hook follows "login_form_{$action}" convention:

function login_header( $title = 'Log In', $message = '', $wp_error = null ) {
	global $error, $interim_login, $action;

	do_action( "pre_login_form_{$action}", $title, $message, $wp_error );

Option 2: The new hook uses the function's name and also passes the $action.

function login_header( $title = 'Log In', $message = '', $wp_error = null ) {
	global $error, $interim_login, $action;

	do_action( "pre_login_header", $title, $message, $wp_error, $action );

Both of the above options accomplish the ticket's request and @SergeyBiryukov's observation:

On second thought, hooks before any output might indeed be helpful for redirects or more extensive customizations.

[hellofromTonya]

Is it still needed today?

My first impressions lean towards "no" for these reasons:

• The ticket being stale this long can indicate not enough interest or use cases.
• As previously noted, there are plenty of filter and action hooks available for customization including style, messaging, redirects, etc.

In considering adding additional hooks, benefits vs impacts need to also be considered.

• Impacts:
  • Performance: each new hook adds processing time and memory usage.
  • Maintenance: initial changes, long term backwards-compatibility, documentation, etc.
• Benefits:
  • Are there enough use cases?
  • is there enough interests and value to users and extenders?

If benefits outweigh the impacts, then adding the hooks makes sense.

For the reasonings I shared, I'll mark the ticket as a close candidate. If there's no follow-up or continued discussion within 2 months, this ticket can be closed. Please note, if it gets closed, it could be reopened when there's enough interest and benefits to move it forward.