使用Vim或类似工具查找Wordpress钩子和过滤器

Question

Wordpress allows you to extend its core using "hooks" and "filters." For example, to execute something quite early in the execution process I may write

add_action( 'init', function() { // Do something } );

Filters work similarly. The function that defines a hook is do_action , so to create the init hook a core developer wrote

do_action( 'init' );

do_action accepts several optional arguments that this hook doesn't demonstrate. The function names for filters are add_filter and apply_filter.

Say I'm browsing the source code of some plugin and it's using a hook from one of the source files and I don't know which one. What is the easiest way to locate it?

In Vim I use ctags a lot and I was hoping that it was possible to do something similar, only instead of giving the function name I could give the filter or hook name. Any ideas?

(If it can't be done from within Vim, like ctags, second best would be to run a command that will locate the script for me. This could also be acceptable if it is the best solution)

Answer 1

Say I'm browsing the source code of some plugin and it's using a hook from one of the source files and I don't know which one. What is the easiest way to locate it?

I use grep. Couldn't work without it. grep gets me just about anything I want. grep -Rni "do_action( 'init'" * should find the 'init' hook. You can use regex in the search string if you need to as well as tell it to ignore particular files and/or directories. I've tried other options but just haven't ever been sold on anything else. grep is quick and clean.

This isn't a 'Vim' answer but you did say 'or similar' :)

There is a very good hook database at http://adambrown.info/p/wp_hooks/version/3.4 too.

Answer 2

I've had to do this quite a lot lately so I wrote a little Vim plugin to ease the process.

Simply place the caret on name of the hook or filter, press Leader + f to find the hooked functions, or Leader + F to find the hook/filter definition.

To install:

cd ~/.vim/bundle && git clone https://github.com/borzhemsky/wp-hook-finder.git

Add the keybindings to ~/.vimrc:

nnoremap <Leader>f :FindWPHook<CR>
nnoremap <Leader>F :FindWPHookDef<CR>

Site note: Writing this taught me that, yes, people do things like using add_filter hook their functions to hooks defined with do_action , so searching for occurrences manually can be error-prone.

Answer 3

From the basic to the rather involved:

GREP

Already explained.

GREP FROM VIM OR VIMGREP

If you are already in Vim, you can use the :vimgrep command or its sister :grep :

:vim "do_action( 'init' )" **/*.php | copen

See :help starstar for the ** wildcard that let's you do recursive search. :vimgrep uses an internal method while :grep uses, well… grep . The latter may be faster.

CTAGS

Assuming you have ctags installed, the indexing can be done in the shell or in Vim:

$ ctags -R . <-- in the shell
:!ctags -R . <-- in Vim

and the querying is just a matter of :tag do_action . Read :help tags for an indepth explanation.

CSCOPE

Assuming you have cscope installed, you can use it right from the shell:

$ cscope -R *.php

Once the index is created you can search in cscope 's interface and open the chosen files in your editor.

Assuming your Vim comes with cscope support, you have to:

1. create the index, :!cscope -bR *.php

2. locate the index, :cs add cscope.out

3. *f*ind the *d*efinition, :cs fd do_action

There are other specialized tools like Codesearch or GNU Global but I think that you don't really need to go further than plain grep or, at most, ctags .