Add ability to filter back to blog link on login page

[ebinnion]

There is currently not a way to filter the "Back to {site_name_here}" link at the bottom of the /wp-login.php page.

Depending on context, a user may want to change the text that is displayed in that link as well as the link itself. One example would be that on WordPress.com, we use this wording: "Return to {site_name_here}".

I propose that we add a filter that will allow developers to customize that link depending on context.

[ebinnion]

Adds back_to_blog_link filter to login footer.

[adamsilverstein]

@ebinnion Thanks for the patch! This seems like a useful enhancement.

In 35449.2.diff​ I did a tiny bit of cleanup:

• removed title attribute from link, we are trying not to use those and are even actively removing their existing use from core, see #24766
• removed escaping from translations, these are considered trusted in core
• added a translator comment so the context of %s in clear
• slight update to the filter description to mach how other filters are described

[DrewAPicture]

@adamsilverstein: 35449.2.diff​ introduces an inconsistency in changing the default "Back to %s" string to "Return to %s" while naming the filter "back_to_blog_link". We should probably pick one :-)

[audrasjb]

Refreshes the patch against trunk and recent string changes

[audrasjb]

35449.3.diff refreshes the patch against trunk and against some string changes that happened in WP 5.6.

I tested it using the following snippet:

<?php
function my_login_site_html_link( $link ) {
        return '<a href="' . esc_url( home_url( '/' ) ) . '">' . __( 'Back to the website', 'my-theme' ) . '</a>';
}
add_filter( 'login_site_html_link', 'my_login_site_html_link', 10, 1 );

Works fine (see before/after screenshots below).

My only concern is about the name of the filter. Any thought?

[audrasjb]

Before 35449.3.diff

[audrasjb]

After 35449.3.diff using the new filter

[hellofromTonya]

Replying to audrasjb:

My only concern is about the name of the filter. Any thought?

The filter is filtering the HTML link <a> element for going back to the root of the website. And it's on the login page.

I think 'login_site_html_link' concisely captures what is being filtered.

[hellofromTonya]

After applying '← Back to home' to the filter

[hellofromTonya]

Tested. Works for me ✅

Used this testing code:

<?php
add_filter(
        'login_site_html_link',
        function () {
                return sprintf(
                        '<a href="%s">%s</a>',
                        esc_url( home_url( '/' ) ),
                        /* translators: %s: Site title. */
                        esc_html_x( '&larr; Back to home', 'site' )
                );
        }
);

@audrasjb the patch escapes the URL, but not the translated string.

<?php
_x( '&larr; Go to %s', 'site' )

Shouldn't this be changed to?

<?php
esc_html_x( '&larr; Go to %s', 'site' )

[audrasjb]

Hey @hellofromTonya thanks for testing the patch!
There is no need to escape Core translation strings, as Core translations are validated by trusted editors (General Translation Editors of each Locale) :)

Given the patch has been tested, let's mark this for commit

[sabernhardt]

Small change: get_bloginfo() needs the display context (see #26811).

get_bloginfo( 'title', 'display' )

[audrasjb]

Add display param to get_bloginfo( 'title' )

[audrasjb]

Thanks @sabernhardt, this is a good enhancement too. Patch updated accordingly.

[adamsilverstein]

35449.1.diff​ looks good! I'll give this a final test suite run and get it committed.

Trac ticket: https://core.trac.wordpress.org/ticket/35449

[adamsilverstein]

In 50117:

Login: Enable filtering the back to blog link.

Add a new login_site_html_link filter that developers can use to adjust the "Go to site" link displayed in the login page footer.

Props ebinnion, DrewAPicture, audrasjb, hellofromTonya, sabernhardt. 
Fixes #35449.

[adamsilverstein]

Marking this "needs dev note" to make sure we document this filter in the release notes.

Merged with changeset https://core.trac.wordpress.org/changeset/50117.

[audrasjb]

Dev note published: ​https://make.wordpress.org/core/2021/02/16/login-registration-screens-changes-in-wordpress-5-7/