Switch_to_blog() no longer works in Customize using Multisite.

[csschris]

A change in /wp-includes/class-wp-customize-setting.php seems to have broken something.

Code that uses switch_to_blog() no longer gets run in customize view.

Had no problem in 4.1

[ocean90]

Can you please provide the code which is broken now?

[csschris]

Replying to ocean90:

Can you please provide the code which is broken now?

I'm in the process of narrowing it down.

seems like the

_preview_filter() function on line 167 /wp-includes/class-wp-customize-setting.php

[westonruter]

Code that uses switch_to_blog() no longer gets run in customize view.

Please share this code.

[csschris]

Replying to westonruter:

Code that uses switch_to_blog() no longer gets run in customize view.

Please share this code.

eg code could be

switch_to_blog(1);
echo bloginfo('name');
restore_current_blog();

shows current blog name not the blogname for site with id of 1

[westonruter]

OK, then it is probably due to #30988 and this logic added to WP_Customize_Setting::preview():

if ( ! isset( $this->_original_value ) ) {
	$this->_original_value = $this->value();
}

Since the preview() method gets evaluated before the switch_to_blog() call, it would the later prevent the switch_to_blog() call from overriding this initial value.

However… is the plugin code intending to allow the Customizer to change the blogname for another site? Or are you just wanting to display the blogname for another site? If the latter case, then we probably need to update the _preview_filter method from modifying the value if the current blog is not the same as the initial blog when the preview method is called.

[csschris]

Replying to westonruter:

OK, then it is probably due to #30988 and this logic added to WP_Customize_Setting::preview():

if ( ! isset( $this->_original_value ) ) {
	$this->_original_value = $this->value();
}

Since the preview() method gets evaluated before the switch_to_blog() call, it would the later prevent the switch_to_blog() call from overriding this initial value.

However… is the plugin code intending to allow the Customizer to change the blogname for another site? Or are you just wanting to display the blogname for another site? If the latter case, then we probably need to update the _preview_filter method from modifying the value if the current blog is not the same as the initial blog when the preview method is called.

In that example I just want to show the name of the other blog. My actual use case is I show a menu from the main site (blog id 1) on all sub sites.

[westonruter]

But to confirm, you aren't intending to be able to modify that other blog's menu (or any other setting) from the current blog, right? I can understand wanting to use switch_to_blog to grab content for display within the Customizer preview, but using the Customizer to actually modify settings associated with other blogs would be a whole different animal.

[westonruter]

​https://github.com/xwp/wordpress-develop/pull/71

[csschris]

Replying to westonruter:

But to confirm, you aren't intending to be able to modify that other blog's menu (or any other setting) from the current blog, right? I can understand wanting to use switch_to_blog to grab content for display within the Customizer preview, but using the Customizer to actually modify settings associated with other blogs would be a whole different animal.

Definitely not modifying other sites menu through Customizer. Just displaying a menu from another site which worked fine in 4.1 and below.

[westonruter]

Cool. @csschris would you please take a look at 31428.diff​ and see if it resolves your issue?

[csschris]

Replying to westonruter:

Cool. @csschris would you please take a look at 31428.diff​ and see if it resolves your issue?

Thx @westonruter it does in fact resolve the issue.

[westonruter]

Additional changes: ​https://github.com/xwp/wordpress-develop/compare/e3a095558049f334d3a3b701dfca916bd7bebab8...e43e91e26f1460641e7fb3a69635c69c4e96a5c8

[westonruter]

In 31428.2.diff​"

• Have WP_Customize_Setting::is_current_blog_previewed() return null if not previewed yet
• Add unit test for WP_Customize_Setting::is_current_blog_previewed()
• Clean up php coding standards in code around patch.

[csschris]

A note for recreating this bug.

Before @westonruter's fix this bug was specifically showing itself when using switch_to_blog then pulling menus by location and/or using has_nav_menu() to conditionally display content from other blogs.

I was confused because in another section I call switch_to_blog and then call a menu directly by ID without checking has_nav_menu and it did not break in customizer view in 4.1.1

[ocean90]

31428.2.diff​:

• For 4.1.2 we need a patch without a PHP coding standards clean up.
• test_previewing_with_switch_to_blog() should either be split into two tests (one for single, one for multisite) or $this->markTestSkipped() should be on top.

[westonruter]

Additional changes: ​https://github.com/xwp/wordpress-develop/compare/e43e91e26f1460641e7fb3a69635c69c4e96a5c8...47a7f266127c332bca8b1ec7c51de039ee3b9d2e

[westonruter]

Replying to ocean90:

31428.2.diff​:

• For 4.1.2 we need a patch without a PHP coding standards clean up.
• test_previewing_with_switch_to_blog() should either be split into two tests (one for single, one for multisite) or $this->markTestSkipped() should be on top.

OK, 31428.3.diff​ now addresses these.

[westonruter]

Additional change (Add markTestSkipped to test_previewing_with_switch_to_blog if not is_multisite): ​https://github.com/xwp/wordpress-develop/commit/097e1f88e8a5b12ec3947d8b83e8680214f64ce0

[ocean90]

In 31707:

Customizer: Return the original value when filtering theme mods/options and the current blog has changed.

props westonruter.
fixes #31428.

[ocean90]

Reopening for 4.1.2.

[ocean90]

It's late…

[nicholas_io]

I have a multisite installation that performs a lot of switch_to_blog() on the main site to pull posts for another site and it`s working well in customizer preview with 4.1.1.

[pento]

With 4.2 being just around the corner, we're going to skip this for 4.1.2.

[boonebgorges]

In 32840:

Use assertFalse() rather than assertNull() in Tests_WP_Customize_Setting::test_is_current_blog_previewed().

is_current_blog_previewed() returns a boolean.

See #31428.