git.cworth.org Git - sup/blob - lib/sup/hook.rb

   1 module Redwood
   2
   3 class HookManager
   4   class HookContext
   5     def initialize name
   6       @__say_id = nil
   7       @__name = name
   8       @__locals = {}
   9     end
  10
  11     attr_writer :__locals
  12     def method_missing m, *a
  13       case @__locals[m]
  14       when Proc
  15         @__locals[m] = @__locals[m].call(*a) # only call the proc once
  16       when nil
  17         super
  18       else
  19         @__locals[m]
  20       end
  21     end
  22
  23     def say s
  24       if BufferManager.instantiated?
  25         @__say_id = BufferManager.say s, @__say_id
  26         BufferManager.draw_screen
  27       else
  28         log s
  29       end
  30     end
  31
  32     def log s
  33       Redwood::log "hook[#@__name]: #{s}"
  34     end
  35
  36     def ask_yes_or_no q
  37       if BufferManager.instantiated?
  38         BufferManager.ask_yes_or_no q
  39       else
  40         print q
  41         gets.chomp.downcase == 'y'
  42       end
  43     end
  44
  45     def get tag
  46       HookManager.tags[tag]
  47     end
  48
  49     def set tag, value
  50       HookManager.tags[tag] = value
  51     end
  52
  53     def __binding
  54       binding
  55     end
  56
  57     def __cleanup
  58       BufferManager.clear @__say_id if @__say_id
  59     end
  60   end
  61
  62   include Singleton
  63
  64   def initialize dir
  65     @dir = dir
  66     @hooks = {}
  67     @descs = {}
  68     @contexts = {}
  69     @tags = {}
  70
  71     Dir.mkdir dir unless File.exists? dir
  72
  73     self.class.i_am_the_instance self
  74   end
  75
  76   attr_reader :tags
  77
  78   def run name, locals={}
  79     hook = hook_for(name) or return
  80     context = @contexts[hook] ||= HookContext.new(name)
  81     context.__locals = locals
  82
  83     result = nil
  84     begin
  85       result = context.instance_eval @hooks[name], fn_for(name)
  86     rescue Exception => e
  87       log "error running hook: #{e.message}"
  88       log e.backtrace.join("\n")
  89       @hooks[name] = nil # disable it
  90       BufferManager.flash "Error running hook: #{e.message}" if BufferManager.instantiated?
  91     end
  92     context.__cleanup
  93     result
  94   end
  95
  96   def register name, desc
  97     @descs[name] = desc
  98   end
  99
 100   def print_hooks f=$stdout
 101 puts <<EOS
 102 Have #{@descs.size} registered hooks:
 103
 104 EOS
 105
 106     @descs.sort.each do |name, desc|
 107       f.puts <<EOS
 108 #{name}
 109 #{"-" * name.length}
 110 File: #{fn_for name}
 111 #{desc}
 112 EOS
 113     end
 114   end
 115
 116   def enabled? name; !hook_for(name).nil? end
 117
 118 private
 119
 120   def hook_for name
 121     unless @hooks.member? name
 122       @hooks[name] =
 123         begin
 124           returning IO.read(fn_for(name)) do
 125             log "read '#{name}' from #{fn_for(name)}"
 126           end
 127         rescue SystemCallError => e
 128           #log "disabled hook for '#{name}': #{e.message}"
 129           nil
 130         end
 131     end
 132
 133     @hooks[name]
 134   end
 135
 136   def fn_for name
 137     File.join @dir, "#{name}.rb"
 138   end
 139
 140   def log m
 141     Redwood::log("hook: " + m)
 142   end
 143 end
 144
 145 end