Changing plugin slug with update

Question

My plugin uses camelCase in file and folder like

myPlugin/myPlugin.php

I've encountered several issues with this on plugin updates. Most of them work just fine and it's more a cosmetic thing but on some places I just like to go with all lowercase.

What's the best way (or is there any) to update the plugin to

myplugin/myplugin.php

without hazzle the users?

Please note this is a custom plugin and not available on the repo and yes I had to do it lowercase in the first place.

Answer 1

If you just wanted to just change the filename you would have both myPlugin.php and myplugin.php in the plugin and then update the option active_plugins in the database to the new name. Once all of the users have updated you can remove myPlugin.php.

But you want to rename both the folder and filename.

I would get myPlugin/myPlugin.php to install and activate myplugin/myplugin.php. Once myplugin/myplugin.php is installed myplugin/myplugin.php can delete myPlugin/myPlugin.php

You can use TGM Plugin Activation for installing and activating the new plugin. Make to include a check so that the new and old version are not running at the same time.

You can use deactivate_plugins() and delete_plugins() to deactivate and uninstall the plugin.

Answer 2

Ok, I did some research/testing on it an in short terms:

Don't use uppercase in the first place!

I've currently noticed only one problem where the ajax based update from the plugins overview (introduced in WP 4.2) throws a JS error but it may be a problem in the future.

This is because the ajax response uses sanitize_key in the wp_ajax_update_plugin method (browse in trac).

The sanitize_key method does next to sanitization a strtolower which causes the "myPlugin" gets a "myplugin".

The updateSuccess method tries now to update the row where the slug is "myplugin" instead of "myPlugin".

This could be prevented by changing line 694 in wp-admin/includes/class-wp-plugins-list-table.php from

    printf( "<tr id='%s' class='%s' data-slug='%s'>",
        $id,
        $class,
        $plugin_slug
    );

to

    printf( "<tr id='%s' class='%s' data-slug='%s'>",
        $id,
        $class,
        sanitize_key($plugin_slug)
    );

todo: open ticket Ticket #35032

To answer the initial question

You can change the slug on a plugin update but you have to take care of following:

• the following code must be included in the old version (eg. `myPlugin/myPlugin.php)
• the updated version must have a slug of `myplugin/myplugin.php
• don't use delete_plugin() which may trigger an uninstall.php and removes plugins data

Here's the code you can start with:

//hook into when new plugin has been successfully updated
add_filter( 'upgrader_post_install', 'my_move_plugin_slug', 10 ,3 );

function my_move_plugin_slug($should_be_true, $hook_extra, $result){

    global $wpdb, $wp_filesystem;

    $from = 'myPlugin/myPlugin.php';
    $to = 'myplugin/myplugin.php';

    //some general checks
    if(!$should_be_true || !isset($hook_extra['plugin']) || $hook_extra['plugin'] != $to) return $should_be_true;

    $old_destination = $result['local_destination'].'/'.dirname($from).'/';

    //old location doesn't exist (anymore)
    if(!is_dir($old_destination)) return $should_be_true;
    //new location is the same as the old one
    if($old_destination == $result['destination']) return $should_be_true;

    //do the magic

    //rewrite location in the database
    echo '<p>Moving the plugin to new location… ';
    if(false !== $wpdb->query($wpdb->prepare("UPDATE {$wpdb->options} SET `option_value` = replace(option_value, %s, %s)", $from, $to))){
        echo '<strong>done</strong>';
    }
    echo '</p>';

    //delete folder
    echo '<p>Removing the old directory of the plugin… ';
    if($wp_filesystem->delete( $old_destination , true )){
        echo '<strong>done</strong>';
    }
    echo '</p>';

}

Second method

If you have a dedicate batch update progress in you plugin like I have you can use this code which is in my opinion a bit safer as it's triggered by explicit user interaction and doesn't require wp_filesystem:

function do_change_plugin_slug(){

    global $wpdb;

    $from = 'myMail/myMail.php';
    $to = 'mymail/mymail.php';

    $old_destination = WP_PLUGIN_DIR.'/'.$from;
    $new_destination = WP_PLUGIN_DIR.'/'.$to;

    //old location doesn't exist (anymore)
    if(!file_exists($old_destination)) return true;
    //new location is the same as the old one
    if($old_destination == $new_destination) return true;

    //do the magic

    echo 'Removing the old file of the plugin… ';
    if(rename( $old_destination , dirname($old_destination).'/'.basename($new_destination) )){
        echo 'done';
    }else{
        echo 'failed';
    }
    echo "\n";

    echo 'Removing the old directory of the plugin… ';
    if(rename( dirname($old_destination) , dirname($new_destination) )){
        echo 'done';
    }else{
        echo 'failed';
    }
    echo "\n";

    //rewrite location in the database
    echo 'Moving the plugin to new location… ';
    if(false !== $wpdb->query($wpdb->prepare("UPDATE {$wpdb->options} SET `option_value` = replace(option_value, %s, %s)", $from, $to))){
        echo 'done';
    }else{
        echo 'failed';
    }
    echo "\n";

    return true;

}

In the end you should always make sure the user understands what's going on and/or why this is a necessary step.