From b9d8c71cecdca157bbc98c0eb7900d4084ced0f7 Mon Sep 17 00:00:00 2001
From: Manuel Familia <manuelgfx@gmail.com>
Date: Tue, 16 Feb 2016 19:58:30 -0500
Subject: [PATCH] Allow configuration of alphabet for hashids

---
 README.md                 |  3 +++
 lib/hashid/rails.rb       | 10 ++++++++--
 spec/hashid/rails_spec.rb | 29 +++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 872111d..f9b078a 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,9 @@ easily reverse engineer your ids, create an initializer and:
 Hashid::Rails.configure do |config|
   config.secret = 'my secret'
   config.length = 6
+  # config.alphabet is optional, hashids provides a default
+  # alphabet that consists of all characters [a-zA-Z0-9]
+  config.alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
 end
 ```
 
diff --git a/lib/hashid/rails.rb b/lib/hashid/rails.rb
index 4a478c6..b438b75 100644
--- a/lib/hashid/rails.rb
+++ b/lib/hashid/rails.rb
@@ -38,7 +38,12 @@ module ClassMethods
       def hashids
         secret = Hashid::Rails.configuration.secret
         length = Hashid::Rails.configuration.length
-        Hashids.new("#{table_name}#{secret}", length)
+        alphabet = Hashid::Rails.configuration.alphabet
+
+        arguments = ["#{table_name}#{secret}", length]
+        arguments << alphabet if alphabet.present?
+
+        Hashids.new(*arguments)
       end
 
       def encode_id(id)
@@ -61,11 +66,12 @@ def model_reload?
     end
 
     class Configuration
-      attr_accessor :secret, :length
+      attr_accessor :secret, :length, :alphabet
 
       def initialize
         @secret = ''
         @length = 6
+        @alphabet = nil
       end
     end
 
diff --git a/spec/hashid/rails_spec.rb b/spec/hashid/rails_spec.rb
index ecee359..c82c089 100644
--- a/spec/hashid/rails_spec.rb
+++ b/spec/hashid/rails_spec.rb
@@ -56,6 +56,35 @@
       end
     end
 
+    describe 'alphabet' do
+      let(:expected_alphabet) { 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' }
+      let(:config) { Hashid::Rails.configuration }
+
+      context 'with custom alphabet' do
+        before :each do
+          Hashid::Rails.configure do |config|
+            config.alphabet = expected_alphabet
+          end
+        end
+
+        it 'initializes hashid correctly'  do
+          expect(Hashids).to receive(:new)
+                         .with('models', config.length, expected_alphabet)
+
+          Model.hashids
+        end
+      end
+
+      context 'with no custom alphabet' do
+        it 'initializes hashid correctly' do
+          expect(Hashids).to receive(:new)
+                         .with('models', config.length)
+
+          Model.hashids
+        end
+      end
+    end
+
   end
 
   describe '#reload' do