Configuring include-search for PHP

Question

I just learned of the existence of include-search, but even after reading :help include-searchand :help includeexpr I'm not sure what I need to do to have [I find included and required files.

How do I configure include-search for both included and required PHP files?

I think I need to set includeexpr such that it allow searching files whether they were included using require, require_once, include, or include_once; but I'm not sure. And I don't quite get what the variable is supposed to have.

Answer 1

The default php ftplugin already does that for you:

setlocal include=\\\(require\\\|include\\\)\\\(_once\\\)\\\?

Add filetype plugin indent on to your ~/.vimrc if it's not already there to benefit from Vim's filetype detection.