From 49153dfa2be280da249bd7e76334716bb23ec61e Mon Sep 17 00:00:00 2001
From: John Mair <jrmair@gmail.com>
Date: Mon, 17 Oct 2011 14:09:12 +1300
Subject: [PATCH] hooks refactor

---
 lib/pry.rb              | 18 ++++++++---------
 lib/pry/hooks.rb        | 45 +++++++++++++++++++++++++++++++++++++++++
 lib/pry/pry_instance.rb | 11 +++++++---
 3 files changed, 62 insertions(+), 12 deletions(-)
 create mode 100644 lib/pry/hooks.rb

diff --git a/lib/pry.rb b/lib/pry.rb
index 4d2a8606..ae6aec8a 100644
--- a/lib/pry.rb
+++ b/lib/pry.rb
@@ -4,19 +4,19 @@
 
 require 'pp'
 require 'pry/helpers/base_helpers'
+require 'pry/hooks'
+
 class Pry
   # The default hooks - display messages when beginning and ending Pry sessions.
-  DEFAULT_HOOKS = {
-    :before_session => proc do |out, target, _pry_|
-      # ensure we're actually in a method
-      file = target.eval('__FILE__')
+  DEFAULT_HOOKS = Pry::Hooks.new.add_hook(:before_session) do |out, target, _pry_|
+    # ensure we're actually in a method
+    file = target.eval('__FILE__')
 
-      # /unknown/ for rbx
-      if file !~ /(\(.*\))|<.*>/ && file !~ /__unknown__/ && file != "" && file != "-e"
-        _pry_.process_line("whereami 5", "", target)
-      end
+    # /unknown/ for rbx
+    if file !~ /(\(.*\))|<.*>/ && file !~ /__unknown__/ && file != "" && file != "-e"
+      _pry_.process_line("whereami 5", "", target)
     end
-  }
+  end
 
   # The default print
   DEFAULT_PRINT = proc do |output, value|
diff --git a/lib/pry/hooks.rb b/lib/pry/hooks.rb
new file mode 100644
index 00000000..55984a69
--- /dev/null
+++ b/lib/pry/hooks.rb
@@ -0,0 +1,45 @@
+class Pry
+  class Hooks
+
+    def initialize
+      @hooks = {}
+    end
+
+    # Add a new callable to be executed for the `name` hook.
+    # @param [Symbol] name The name of the hook.
+    # @param [#call] callable The callable.
+    # @yield The block to use as the callable (if `callable` parameter not provided)
+    def add_hook(name, callable=nil, &block)
+      @hooks[name] ||= []
+
+      if block
+        @hooks[name] << block
+      elsif callable
+        @hooks[name] << callable
+      else
+        raise ArgumentError, "Must provide a block or callable."
+      end
+
+      self
+    end
+
+    # Execute the list of callables for the `name` hook.
+    # @param [Symbol] name The name of the hook to execute.
+    # @param [Array] args The arguments to pass to each callable.
+    def exec_hook(name, *args, &block)
+      Array(@hooks[name]).each { |v| v.call(*args, &block) }
+    end
+
+    # Clear the list of callables for the `name` hook.
+    # @param [Symbol] The name of the hook to delete.
+    def delete_hook(name)
+      @hooks[name] = []
+    end
+
+    # Clear all hooks.
+    def reset
+      @hooks = {}
+    end
+
+  end
+end
diff --git a/lib/pry/pry_instance.rb b/lib/pry/pry_instance.rb
index 0ca25043..9552e20d 100644
--- a/lib/pry/pry_instance.rb
+++ b/lib/pry/pry_instance.rb
@@ -149,7 +149,8 @@ class Pry
   # Initialize the repl session.
   # @param [Binding] target The target binding for the session.
   def repl_prologue(target)
-    exec_hook :before_session, output, target, self
+    hooks.exec_hook :before_session, output, target, self
+#    exec_hook :before_session, output, target, self
     initialize_special_locals(target)
 
     @input_array << nil # add empty input so _in_ and _out_ match
@@ -161,7 +162,7 @@ class Pry
   # Clean-up after the repl session.
   # @param [Binding] target The target binding for the session.
   def repl_epilogue(target)
-    exec_hook :after_session, output, target, self
+    hooks.exec_hook :after_session, output, target, self
 
     Pry.active_sessions -= 1
     binding_stack.pop
@@ -230,11 +231,13 @@ class Pry
     result
   rescue CommandError => e
     output.puts "Error: #{e.message}"
+    result = e.message
     @suppress_output = true
   rescue RescuableException => e
-    set_last_exception(e, target)
+    result = set_last_exception(e, target)
   ensure
     update_input_history(code)
+    hooks.exec_hook :after_eval, result, self
   end
 
   # Perform a read.
@@ -254,6 +257,7 @@ class Pry
     val = ""
     loop do
       val = retrieve_line(eval_string, target)
+      hooks.exec_hook :after_retrieve_line, val, self
       process_line(val, eval_string, target)
 
       break if valid_expression?(eval_string)
@@ -261,6 +265,7 @@ class Pry
 
     @suppress_output = true if eval_string =~ /;\Z/ || eval_string.empty?
 
+    hooks.exec_hook :after_read, eval_string, self
     eval_string
   end