Admin bar 'Purge Cache' button disappears after updating to 2.3.4

[mrrobot47]

As an administrator, the "Purge Cache" button in the WordPress admin bar is no longer visible after updating the Nginx Helper plugin to the latest version (2.3.4).

This issue appears to have been introduced in Pull Request #420, where the permission check for displaying the button was changed from the general manage_options capability to a more specific Nginx Helper | Purge cache capability.

While this new capability is correctly added to the 'administrator' role upon a fresh activation of the plugin, it seems this logic is not triggered during the update process. As a result, administrators who update the plugin lose access to the button because their role doesn't have the newly required permission.

Workaround:
Deactivating and then reactivating the plugin successfully restores the "Purge Cache" button, as this process re-runs the activation hook that grants the necessary capability.

Suggested Solution:
An update routine should be added to ensure that the Nginx Helper | Purge cache capability is granted to the administrator role during the plugin update process, not just on activation.

[joelabreo227]

Thanks for reporting this @mrrobot47. We're working on a hotfix.

[nitun]

https://wordpress.org/support/topic/purge-not-working-7/.

[Vedant-Gandhi]

The issue in version 2.3.4 has been fixed in version 2.3.5. In 2.3.4, the plugin's permission logic changed from checking the manage_options capability to the Nginx Helper | Purge cache capability, which could cause administrators to lose the ability to purge the cache after an update. A temporary solution was to deactivate and reactivate the plugin, which would restore the necessary permissions.

In 2.3.5, the plugin now detects when the plugin version has changed and automatically assigns the necessary capabilities to administrators. This ensures the purge functionality works correctly without any manual intervention.

cc - @joelabreo227 @mrrobot47

[granaalex]

I noticed the same problem still, under plugin version 2.3.5, and this was over a clean install. Thank you!

[Vedant-Gandhi]

Hi @granaalex, Thanks for reporting this. I wasn't able to replicate the issue on my end with version 2.3.5. Could you please share a few more details about your setup so we can investigate further? For example:

• WordPress version
• PHP version
• Multisite or single-site install
• Whether any role/capability manager plugins are active
• The exact steps you followed that led to the missing "Purge Cache" button.
• The plugin configuration.

cc - @joelabreo227

[granaalex]

Of course, @Vedant-Gandhi

WP version: 6.8.2
PHP version: 8.3.19
Single-site install
No role capability manager plugin installed
The plugin is installed as part of the default one-click installer we provide, it's downloaded straight from the codex, as far as I'm aware
Here's the plugin configuration:

• Enable purge

• Nginx Fastcgi cache

• Using a GET request to PURGE/url

• Purging conditions
  Homepage: both options enabled
  Post/Page/Custom Post type: all three options enabled
  Purge Archives: Only when a post/page/custom post is modified or added, and when a published post/page/custom post is trashed

• Purge Feeds long with posts & pages is on

• Purge AMP URLs along with posts & pages is enabled

• No custom purge URL set up.

Let me know if you need anything else!

[Vedant-Gandhi]

Hi @granaalex , we’ve tried to reproduce it with a fresh install that matches your setup, but haven’t been able to see the same behavior.

purge-cache.mp4

If you or anyone else is able to provide steps that reliably reproduce the problem, we are open to investigating further, but other than that, there isn’t much more we can do directly at this point.

cc - @joelabreo227

[granaalex]

Sorry for the delay! We run the following script through a plugin to update the default settings, meaning the plugin is enabled directly via code:

// Define the `dh_nginx_helper_default_settings` function with the following array.
function dh_nginx_helper_default_settings() {
    return array(
        'enable_purge' => 1,
        'cache_method' => 'enable_fastcgi',
        'purge_method' => 'get_request',
        'enable_map' => 0,
        'enable_log' => 0,
        'log_level' => 'INFO',
        'log_filesize' => '5',
        'enable_stamp' => 0,
        'purge_homepage_on_edit' => 1,
        'purge_homepage_on_del' => 1,
        'purge_archive_on_edit' => 1,
        'purge_archive_on_del' => 1,
        'purge_archive_on_new_comment' => 0,
        'purge_archive_on_deleted_comment' => 0,
        'purge_page_on_mod' => 1,
        'purge_page_on_new_comment' => 1,
        'purge_page_on_deleted_comment' => 1,
        'redis_hostname' => '',
        'redis_port' => '',
        'redis_prefix' => '',
        'purge_url' => '',
        'redis_enabled_by_constant' => 0,
    );
}

// Call the `dh_nginx_helper_default_settings` function and store the settings in a variable.
$default_settings = dh_nginx_helper_default_settings();

// Check if the settings already exist in the database.
$existing_settings = get_option('rt_wp_nginx_helper_options');

// If the settings don't exist, write the defaults to the database using the `update_option` function.
if (false === $existing_settings) {
    update_option('rt_wp_nginx_helper_options', $default_settings);
}

Going through some of the pull requests, it seems that when caching is enabled through the plugin's interface, it sets up the Nginx Helper and Purge cache capabilities and saves them to the database, using this script probably doesn't properly set them up, causing the issue, but I'm not 100% sure.

[szrejder]

I'm having the same problem on multiple WordOps sites (but it's not consistent). It works on some sites, but not on others.

This has happened after a fresh install, but also on servers with multiple sites – it works on some, but not on others. These sites are practically identical, and I haven't been able to find the cause.