The best NeoVim/Vim PHP autocomplete plugin by far
Ever since I started using VIM/NeoVim as my primary IDE for PHP developing I felt the need for better autocomplete, with methods, namespaces, go to definitions and all the good stuff that big IDE's autocomplete system like PHPStorm already have. Many times I've tried and searched for good php autocomplete plugin, but I've never managed to find one.
Basically 2-3 times per year I'm doing research for Vim PHP autocomplete plugins and every time I manage to find new ones that I haven't seen before and I get really exicted to try them. Shortly after, however, I find that they are not what I expect, they break the editor, doesn't work right, or I generally dislike them. Then I go back to my old way of working, depending only on basic autocomplete offered by YouCompleteMe Vim plugin.
Luckly today when searching for 'phpstorm autocomplete vim' this post came up How did I Replace PhpStorm by Vim in my Heart. This post is written by a PHP developer who previously used PHPStorm but successfully switched to Vim / NeoVim. He mentions all the plugins he uses and from there I found the ncm2/ncm2 plugin and phpactor/phpactor.
ncm2 is auto-completion engine, in additional you'll need phpactor/phpactor which feeds data to the auto-completion engine and phpactor/ncm2-phpactor is the link between these two.
Today I'm starting to use this setup, let's see how this goes.. I'll write update post in a few months to tell you if this plugin did the trick for me :)
Update 3 jan 2023 (precisely 3 years of usage)
The plugin so far does excellen job for me. The author of phpactor frequently releases new versions and the package overall has good support. I would definetly say go ahead with my approach and install ncm2, phpactor and ncm2-phpactor for php autocomplete in vim/neovim.