Is there an api equivalent to vim.lsp.get_active_clients()?

[boltlessengineer]

I see null-ls has get_all() and get_available(filetype, method) in null-ls.sources, which returns list of installed sources.

What I want is getting all attached clients, not configured/installed ones. Native LSP supports this feature with vim.lsp.get_active_clients() Does null-ls has api like this?

[jose-elias-alvarez]

Not really, because null-ls does not have the concept of an attached source. When null-ls receives an LSP request / notification, it uses the parameters of the request to determine which sources are available and run the ones that are. A source's availability is determined by:

1. Whether it has been registered at all, which can be controlled with the condition option / manual registration
2. Whether it can run in response to the given parameters, which can be controlled with runtime_condition

We can't accurately check runtime_condition because it depends on the parameters of the underlying request, so the closest you can get is a list of sources that match the current filetype:

local get_active_sources = function()
    local filetype = vim.bo.filetype
    return vim.tbl_filter(function(source)
        return source.filetypes[filetype] or source.filetypes["_all"] and source.filetypes[filetype] == nil
    end, require("null-ls").get_sources())
end

If you think this is useful, I'd be open to a PR that adds a filetype filter option to get_sources().

[boltlessengineer]

I think this would be a really useful feature to have. I was trying to make global statusline showing all active clients, but I couldn't because most of them were inside the null-ls LSP, not independent.

I didn't know there is no attached source concept, but your solution seems enough for me. Thanks!