Prompt message when removing a plugin is sometimes misleading

[bradt]

When you attempt to delete a plugin in 4.6, a JS prompt asks "Are you sure you want to delete <plugin name> and its data?" regardless whether or not there's an uninstall.php in the plugin that will actually delete plugin data.

This is misleading users as many plugins do not include uninstall.php files and do leave behind data.

Plugin authors also intentionally leave an uninstall.php out of their plugin and don't remove data to ensure users don't accidentally delete their data when upgrading a plugin via a "delete - upload new zip" process. This message will be confusing to those users who are trying to upgrade using this process without losing data.

​The plugin delete prompt prior to 4.6 would detect whether an uninstall.php file exists in the plugin and only change the messaging to say that data would be deleted if the uninstall.php existed.

[swissspidy]

Hey there,

Thanks for reporting this! The confirmation dialog has been added as part of Shiny Updates, where plugin deletion was now made shiny.

It's not that difficult to make the text context-aware, but with #20578 in mind it would make sense to not use a simple JS confirm() dialog but a custom modal with three options (uninstall completely, delete only, cancel) Tempted to close this one as a duplicate.

[OriginalEXE]

Not even the existence of uninstall.php can guarantee that the plugin will remove its data (it could be used for something else), I think that's worth thinking about.

[swissspidy]

Replying to OriginalEXE:

Not even the existence of uninstall.php can guarantee that the plugin will remove its data (it could be used for something else), I think that's worth thinking about.

Uhm yes, that's what this file is for. It should definitely not be used for something else.

See ​https://developer.wordpress.org/plugins/the-basics/uninstall-methods/

[mordauk]

I'd love to see ​https://developer.wordpress.org/reference/functions/is_uninstallable_plugin/ get a filter so that plugins can override it.

Right now the determination of whether a plugin should uninstall its data is far too binary. It's either "yes" or "no", there is no "maybe". A plugin is deemed as uninstallable by the presence of uninstall.php, but what a plugin that should be capable of uninstalling its data but the choice needs to be left up to the site administrator?

It's very common for site admins to delete plugins and then immediately re-install the same plugin (perhaps a different version). In order to be good citizens, plugin authors are encouraged to cleanup after themselves and delete their data with uninstall.php, but what about scenarios where you want to give the site admin the choice of cleaning up the data?

I don't believe determining whether data should be deleted on the simple presence of a file is enough. I typically offer site admins the choice of deleting data through a setting like this:

And then in the uninstall.php only deleting the data if that option is checked.

This works very well except it leaves the site admin with the misleading message that Brad initially mentioned. Even with the Remove Data on Uninstall option unchecked, site admins still see:

If we could filter the uninstallable status for plugins, we could give an accurate message to site admins instead of the current, mis-leading message.

[bradt]

@mordauk I think for a plugin to be deleted it has to be deactivated first, and if it's deactivated its filters won't work.

I think the suggestion here is probably the way to go: https://core.trac.wordpress.org/ticket/20578#comment:42. I think you're right @swissspidy, we should close this as a dupe of #20578.

[mordauk]

Ah yes, doh.

[swissspidy]

Alright, let's join efforts over at #20578.