On the register_activation_hook() function of the new plugin use the function deactivate_plugins() (or deactivate_plugin_before_upgrade()) and deactivate the older plugin and also delete the data with delete_option. If you will also delete the files, then use the function uninstall_plugin($plugin); maybe delete_plugins( $plugins, $redirect=”” )
The problem is that you aren’t declaring $dg_options as global here: define(‘DG_OPTION_NAME’, ‘document_gallery’); $dg_options = get_option(DG_OPTION_NAME); During uninstall you aren’t in the global scope, your file is being included by uninstall_plugin(). So you need to add this at the top of the main plugin file: global $dg_options; Really, any time you want a variable to … Read more
WordPress v4.7 has added the REST API into core, so this might explain why your REST functionality is still available even after uninstalling the REST API plugin.
How do you add your rewrite rule? If you are adding it manually (opening the .htaccess and adding the lines by yourself in php) then you are also supposed to remove it manually. As you suggested the best way would then be to use regex. If the rewrite rule was added through the WordPress API … Read more
I’m not in my desktop, but I suspect it won’t be retrieved. But: have you tested it? Does the table gets droped? I’d say you need to declare global $wpdb;, isn’t it? if you don’t have any, a tool like FirePHP is really handy when developing anyway, this seems a case where is pretty harmless … Read more
You should be using the register_deactivation_hook and/or register_uninstall_hooks. That may be why some functions don’t work. I’d have to do some testing to be sure, but loading your method directly like WP_Plugin_Janitor::cleanup( $opt, $cpt, $tax ); seems like a pretty good way to skip over some of the WordPress load sequence or to run things … Read more
Custom message on plugin uninstall
Using the uninstall hook would be legitimate if it worked, but it dumps the same error as the uninstall file. It would have more chances of working as it loads the main plugin file to perform the uninstall function, but if the taxonomy is not registered anymore (and it is not, as we need to … Read more
Does your plugin use a version number? On plugin activation you can compare the version number and use the code you have above to remove the ‘old’ options if they exist. if ( $myplugin_version > 3.0 ) { // Remove all plugin options with the prefix “myplugin_” }
As the other answers seem to imply, there is no built-in way to do this. There is no theme uninstall API similar to that for plugins. There is actually a long-standing ticket to get this feature added to WordPress core, so that themes can uninstall themselves. The consensus from the lead developers there seems to … Read more