2 -- SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 -- Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
5 -- All rights reserved.
7 -- Redistribution and use in source and binary forms, with or without
8 -- modification, are permitted provided that the following conditions
10 -- 1. Redistributions of source code must retain the above copyright
11 -- notice, this list of conditions and the following disclaimer.
12 -- 2. Redistributions in binary form must reproduce the above copyright
13 -- notice, this list of conditions and the following disclaimer in the
14 -- documentation and/or other materials provided with the distribution.
16 -- THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 -- ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 -- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 -- ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 -- FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 -- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 -- OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 -- HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 -- LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 -- OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 local registered_hooks = {}
36 -- Register a hook type; these are the names that hooks may be registered for.
37 -- It is expected that modules will register all of their hook types upon
38 -- initial load. Other modules may then, at any time, register a hook for these
41 -- Naming convention: hook types should be sensible named, preferably prefixed
42 -- with the name of the module that registered them. They would also ideally
43 -- describe an action that may or may not match a function name.
44 -- e.g. config.reloaded which takes place after config has been reloaded,
45 -- possibly from a different source.
46 function hook.registerType(hooktype)
47 registered_hooks[hooktype] = {}
50 function hook.register(hooktype, hookfunc)
51 local selected_hooks = registered_hooks[hooktype]
52 if selected_hooks == nil then
53 print("Tried registering a hook for an unknown hook type: " ..
57 selected_hooks[#selected_hooks + 1] = hookfunc
58 registered_hooks[hooktype] = selected_hooks
61 -- Takes a hooktype and runs all functions associated with that specific hook
62 -- type in the order that they were registered in. This ordering should likely
63 -- not be relied upon.
64 function hook.runAll(hooktype)
65 local selected_hooks = registered_hooks[hooktype]
66 if selected_hooks == nil then
67 -- This message, and the print() above, should only be seen by
68 -- developers. Hook type registration should have happened at
69 -- module load, so if this hasn't happened then we have messed
70 -- up the order in which we've loaded modules and we need to
71 -- catch that as soon as possible.
72 print("Tried to run hooks for an unknown hook type: " ..
76 if #selected_hooks > 0 then
77 for _, func in ipairs(selected_hooks) do
81 return #selected_hooks