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