Easily create custom completion menus using any dictionary/json file, in the format:

{ "word(" : { "kind" : "f", "menu" : "menu", "info" : "info" } }

Or a tab-separated values file, like this:

word kind menu info

So, for instance, a WordPress function (a full example wordpress.json file is included in this repo):

{
  "get_bloginfo(" : {
    "kind" : "f",
    "menu" : "string $show, string $filter | string",
    "info" : "Retrieves information about the current site.",
  }
}

Or, as tab-separated values:

get_bloginfo( f string $show, string $filter | string Retrieves information about the current site.

See :help complete-items for more info:

word		the text that will be inserted, mandatory
kind		single letter indicating the type of completion
menu		extra text for the popup menu, displayed after "word"
            or "abbr"
info		more information about the item, can be displayed in a
            preview window

Your custom completion file will show up as a "full" complete menu similar to the omnicomplete menu, like so:

By itself, this plugin does nothing. Only by setting a couple dictionaries in your .vimrc will <C-X><C-U> use the completion function generated by your file.

g:customcpt_funcs (required): A Dictionary with a function name for a key and a List of files to use for completion with it

let g:customcpt_funcs = {
	\ "WPComplete" : [
		\ $HOME . "/.vim/wordpress.json",
	\ ]
\ }

g:customcpt_types (optional): A Dictionary with a comma-separated list of filetypes as keys and the name of a completion function to use with them

let g:customcpt_types =  {
	\ "php,php.html" : "WPComplete",
\ }

Alternatively, you could just do something like this in your .vimrc:

au FileType php,php.html setlocal completefunc=WPComplete

This plugin is heavily based on @aaronspring’s cdo_lazy_vim plugin. Thanks Aaron! 👋

Thanks also to Steve Losh’s Learn Vimscript the Hard Way and the Stack Exchange community.

Related: CompleteHelper