Basic plugin system.

core/plugin.lua

@@ -0,0 +1,95 @@
+-- An isolated API for plugins
+-- These plugins are not yet made to be a secure sandbox, as hooking
+-- into signal might be destructive or reveal sensitive data.
+-- The goal is to be able to unload a plugin and remove all its' hooks
+-- and commands.
+
+local Plugins = {}
+
+plugin = {}
+local API = {}
+
+-- All these functions start with the 'plugin_id' argument, which
+-- will be auto-bound to the plugin name when called from a plugin.
+function API.HookAdd(plugin_id, event_name, hook_name, callback)
+    local HookName = plugin_id .. ':' .. hook_name
+    local PluginHooks = Plugins[plugin_id].Hooks
+    PluginHooks[#PluginHooks + 1] = HookName
+    hook.Add(event_name, HookName, function(...)
+        local Args = {...}
+        local Success, Message = pcall(callback(unpack(Args)))
+        if not Success then
+            hook.Call("plugin.HookCallFailed", HookName, Message)
+            return nil
+        else
+            return Message
+        end
+    end)
+end
+
+function API.CommandAdd(plugin_id, command_name, arity, callback, access, help)
+    bot:AddCommand(command_name, arity, callback, access, help)
+    local PluginCommands = Plugins[plugin_id].Commands
+    PluginCommands[#PluginCommands + 1] = command_name
+end
+
+function API.Register(plugin_id, plugin_name, version, url, author)
+    local Plugin = Plugins[plugin_id]
+    Plugin.Name = plugin_name
+    Plugin.Version = Version
+    Plugin.URL = url
+    Plugin.Author = author
+
+end
+
+function plugin.Create(plugin_id)
+    local Plugin = {}
+    Plugin.Hooks = {}
+    Plugin.Commands = {}
+
+    Plugin.ID = plugin_id
+    Plugin.Name = ""
+    Plugin.Version = 1.0
+    Plugin.URL = ""
+    Plugin.Author = "Nameless Wonder"
+
+    Plugins[plugin_id] = Plugin
+    Plugins[plugin_id].Env = plugin.PrepareEnvironment(plugin_id)
+end
+
+function plugin.PrepareEnvironment(plugin_id)
+    local function BindPluginID(f)
+        return function(...)
+            local Args = {...}
+            return f(plugin_id, unpack(Args))
+        end
+    end
+    
+    local Env = {}
+    Env.table = require('table')
+    Env.string = require('string')
+    Env.json = require('json')
+
+    Env.plugin = {}
+    for K, F in pairs(API) do
+        Env.plugin[K] = BindPluginID(F)
+    end
+
+    return Env
+end
+
+function plugin.RunCode(plugin_id, code)
+    if not Plugins[plugin_id] then
+        plugin.Create(plugin_id)
+    end
+
+    if code:byte(1) == 27 then
+        return nil, "Refused to load bytecode."
+    end
+    local Function, Message = loadstring(code)
+    if not Function then
+        return nil, Message
+    end
+    setfenv(Function, Plugins[plugin_id].Env)
+    return pcall(Function)
+end

start.lua

@@ -2,6 +2,7 @@ require('core.hook')
 require('core.reactor')
 require('core.irc')
 require('core.bot')
+require('core.plugin')
 
 require('socket')
 local https = require('ssl.https')
@@ -22,7 +23,7 @@ end)
 reactor:Initialize()
 bot:Initialize(irc, ',')
 
-bot:AddCommand('at', 0, function(Username, Channel)
+--[[bot:AddCommand('at', 0, function(Username, Channel)
     local Body, Code, Headers, Status = https.request('https://at.hackerspace.pl/api')
     if Code ~= 200 then
         error(string.format("Status code returned: %i", Code))
@@ -34,7 +35,11 @@ bot:AddCommand('at', 0, function(Username, Channel)
     end
     Channel:Say(table.concat(Users, ','))
 
-end, "Show who's at the Warsaw Hackerspace.")
+end, "Show who's at the Warsaw Hackerspace.")]]--
+
+plugin.RunCode('test', [[plugin.CommandAdd('test', 0, function(Username, Channel)
+    Channel:Say('hello!')
+end, "Test command.", 0)]])
 
 irc:Connect('irc.freenode.net', 6667, 'moonspeak', 'moonspeak', 'moonspeak')
 reactor:Run()