From c6fd2eda3dec3890c5d79322c0e399b4c87df11a Mon Sep 17 00:00:00 2001
From: Achilleas Buisman <accounts@abuisman.nl>
Date: Thu, 1 Dec 2016 14:20:10 +0100
Subject: [PATCH] Make it possible to initialize meta_request in an initializer

---
 README.md                                | 24 ++++++++++
 meta_request/lib/meta_request/railtie.rb | 57 +++++++++++++++++++-----
 2 files changed, 69 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 07e2fab..36fb0a1 100644
--- a/README.md
+++ b/README.md
@@ -52,6 +52,30 @@ You can clear the panel with the usual shortcuts of ⌘+k or ctrl+l.
 
 [![CircleCI](https://circleci.com/gh/dejan/rails_panel.svg?style=svg&circle-token=56cf52dd2729102bb9b6e23d5e2fcc8eff0875b3)](https://circleci.com/gh/dejan/rails_panel)
 
+## Conditional alternative initialization
+
+If you do not want to enable meta_request every time you start the server you can put it like this in your app's Gemfile:
+
+```ruby
+group :development do
+  gem 'meta_request', require: false
+end
+```
+
+Then create an initializer that determines the condition to initialize meta_request:
+
+```ruby
+  # In `config/initializers/benchmarking.rb` (for example)
+  if ENV['USE_RAILS_PANEL']
+    require 'meta_request'
+
+    # Initialize manually since we skipped it in the Gemfile
+    MetaRequest::initialize!(Rails.application)
+  end
+```
+
+This way you can turn meta_request on and off through environment variables. This is useful for projects with different people or when you don't need it every time you work on your app.
+
 ## Licence
 
 Copyright (c) 2012 Dejan Simic
diff --git a/meta_request/lib/meta_request/railtie.rb b/meta_request/lib/meta_request/railtie.rb
index 36e11c8..1102d98 100644
--- a/meta_request/lib/meta_request/railtie.rb
+++ b/meta_request/lib/meta_request/railtie.rb
@@ -1,27 +1,60 @@
 require 'rails/railtie'
 
 module MetaRequest
-  class Railtie < ::Rails::Railtie
+  def self.initialize!(app)
+    raise "MetaRequest initialized twice. Set `require: false' for meta_request in your Gemfile" if @already_initialized
 
-    initializer 'meta_request.inject_middlewares' do |app|
-      app.middleware.use Middlewares::RequestId unless defined?(ActionDispatch::RequestId)
-      app.middleware.use Middlewares::MetaRequestHandler
+    MetaRequest::inject_middlewares!(app)
+    MetaRequest::initialize_log_interceptor!
+    MetaRequest::subscribe_to_notifications!
+
+    @already_initialized = true
+  end
+
+  def self.inject_middlewares!(app)
+    raise "MetaRequest middlewares injected twice. Set `require: false' for meta_request in your Gemfile" if @injected_middlewares
+
+    app.middleware.use Middlewares::RequestId unless defined?(ActionDispatch::RequestId)
+    app.middleware.use Middlewares::MetaRequestHandler
+
+    if defined? ActionDispatch::DebugExceptions
+      app.middleware.insert_before ActionDispatch::DebugExceptions, Middlewares::Headers, app.config
+    else
+      app.middleware.use Middlewares::Headers, app.config
+    end
+
+    app.middleware.use Middlewares::AppRequestHandler
+
+    @injected_middlewares = true
+  end
+
+  def self.initialize_log_interceptor!
+    raise "MetaRequest log interceptor initialized twice. Set `require: false' for meta_request in your Gemfile" if @initialized_log_interceptor
+
+    Rails.logger.extend(LogInterceptor) if Rails.logger
+
+    @initialized_log_interceptor = true
+  end
 
-      if defined? ActionDispatch::DebugExceptions
-        app.middleware.insert_before ActionDispatch::DebugExceptions, Middlewares::Headers, app.config
-      else
-        app.middleware.use Middlewares::Headers, app.config
-      end
+  def self.subscribe_to_notifications!
+    raise "MetaRequest notifications subscribed twice. Set `require: false' for meta_request in your Gemfile" if @subscribed_to_notifications
 
-      app.middleware.use Middlewares::AppRequestHandler
+    AppNotifications.subscribe
+
+    @subscribed_to_notifications = true
+  end
+
+  class Railtie < ::Rails::Railtie
+    initializer 'meta_request.inject_middlewares' do |app|
+      MetaRequest::inject_middlewares!(app)
     end
 
     initializer 'meta_request.log_interceptor' do
-      Rails.logger.extend(LogInterceptor) if Rails.logger
+      MetaRequest::initialize_log_interceptor!
     end
 
     initializer 'meta_request.subscribe_to_notifications' do
-      AppNotifications.subscribe
+      MetaRequest::subscribe_to_notifications!
     end
 
   end