Merge pull request #20 from cbeer/classify-resolvers

Convert resolvers into proper classes

.travis.yml

@@ -0,0 +1,8 @@
+notifications:
+  email: false
+
+rvm:
+  - 2.2
+
+sudo: false
+language: ruby

README.md

@@ -36,7 +36,7 @@ Or install it yourself as:
 By default Riiif is set to load images from the filesystem using the Riiif::FileSystemFileResolver. 
 You can configure how this resolver finds the files by setting this property:
 ```
-    Riiif::FileSystemFileResolver.base_path = '/opt/repository/images/'
+    Riiif::Image.file_resolver.base_path = '/opt/repository/images/'
 ```
 When the Id passed in is "foo_image", then it will look for an image file using this glob: 
 ```
@@ -46,18 +46,18 @@ When the Id passed in is "foo_image", then it will look for an image file using
 ### Images retrieved over HTTP
 It's preferable to use files on the filesystem, because this avoids the overhead of downloading the file.  If this is unavoidable, Riiif can be configured to fetch files from the network.  To enable this behavior, configure Riiif to use an alternative resolver:
 ```
-      Riiif::Image.file_resolver = Riiif::HTTPFileResolver
+      Riiif::Image.file_resolver = Riiif::HTTPFileResolver.new
 ```
 Then we configure the resolver with a mechanism for mapping the provided id to a url:
 ```
-      Riiif::HTTPFileResolver.id_to_uri = lambda do |id| 
+      Riiif::Image.file_resolver.id_to_uri = lambda do |id| 
         "http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/#{id}.jpg/600px-#{id}.jpg"
       end
 ```
 
 This file resolver caches the network files, so you will want to clear out the old files or the cache will expand until you run out of disk space.
 Using a script like this would be a good idea: https://github.com/pulibrary/loris/blob/607567b921404a15a2111fbd7123604f4fdec087/bin/loris-cache_clean.sh
-By default the cache is located in `tmp/network_files`. You can set the cache path like this: `Riiif::HTTPFileResolver.cache_path = '/var/cache'`
+By default the cache is located in `tmp/network_files`. You can set the cache path like this: `Riiif::Image.file_resolver.cache_path = '/var/cache'`
 
 ## Usage
 
@@ -103,11 +103,11 @@ Create an initializer like this in `config/initializers/riiif_initializer.rb`
 
 ```ruby
 # Tell RIIIF to get files via HTTP (not from the local disk)
-Riiif::Image.file_resolver = Riiif::HTTPFileResolver
+Riiif::Image.file_resolver = Riiif::HTTPFileResolver.new
 
 # This tells RIIIF how to resolve the identifier to a URI in Fedora
 DATASTREAM = 'imageContent'
-Riiif::HTTPFileResolver.id_to_uri = lambda do |id| 
+Riiif::Image.file_resolver.id_to_uri = lambda do |id| 
   connection = ActiveFedora::Base.connection_for_pid(id)
   host = connection.config[:url]
   path = connection.api.datastream_content_url(id, DATASTREAM, {})

Rakefile

@@ -4,6 +4,8 @@ require 'rspec/core/rake_task'
 RSpec::Core::RakeTask.new(:spec)
 
 require 'engine_cart/rake_task'
-task :ci => ['engine_cart:generate'] do
-  # run the tests
+task ci: ['engine_cart:generate'] do
+  Rake::Task["spec"].invoke
 end
+
+task default: :ci

app/models/riiif/image.rb

@@ -3,7 +3,7 @@ module Riiif
   class Image
 
     class_attribute :file_resolver, :info_service
-    self.file_resolver = FileSystemFileResolver
+    self.file_resolver = FileSystemFileResolver.new
 
     # this is the default info service
     # returns a hash with the original image dimensions.

lib/riiif/file_system_file_resolver.rb

@@ -1,23 +1,24 @@
 module Riiif
-  module FileSystemFileResolver
-    mattr_accessor :root, :base_path, :input_types
-
-    self.root = File.expand_path(File.join(File.dirname(__FILE__), '../..'))
-    self.base_path = File.join(root, 'spec/samples')
-    self.input_types = %W{png jpg tiff jp jp2}
+  class FileSystemFileResolver
+    attr_accessor :root, :base_path, :input_types
 
+    def initialize
+      @root = ::File.expand_path(::File.join(::File.dirname(__FILE__), '../..'))
+      @base_path = ::File.join(root, 'spec/samples')
+      @input_types = %W{png jpg tiff jp jp2}
+    end
 
-    def self.find(id)
+    def find(id)
       Riiif::File.new(path(id))
     end
 
-    def self.path(id)
+    def path(id)
       search = pattern(id)
       Dir.glob(search).first || raise(ImageNotFoundError, search)
     end
 
 
-    def self.pattern(id)
+    def pattern(id)
       raise ArgumentError, "Invalid characters in id `#{id}`" unless /^[\w\-:]+$/.match(id)
       ::File.join(base_path, "#{id}.{#{input_types.join(',')}}")
     end

lib/riiif/http_file_resolver.rb

@@ -2,32 +2,36 @@
 require 'active_support/core_ext/file/atomic'
 
 module Riiif
-  module HTTPFileResolver
+  class HTTPFileResolver
 
     # Set a lambda that maps the first parameter (id) to a URL
     # Example:
     #
-    # Riiif::HTTPFileResolver.id_to_uri = lambda do |id| 
+    # resolver = Riiif::HTTPFileResolver.new
+    # resolver.id_to_uri = lambda do |id| 
     #  "http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/#{id}.jpg/600px-#{id}.jpg"
     # end
     #
-    mattr_accessor :id_to_uri
+    attr_accessor :id_to_uri
 
-    mattr_accessor :cache_path
-    self.cache_path = 'tmp/network_files'
+    attr_accessor :cache_path
 
+    def initialize
+      @cache_path = 'tmp/network_files'
+    end
 
-    def self.find(id)
-      remote = RemoteFile.new(uri(id))
+    def find(id)
+      remote = RemoteFile.new(uri(id), cache_path: cache_path)
       Riiif::File.new(remote.fetch)
     end
 
     class RemoteFile
       include ActiveSupport::Benchmarkable
       delegate :logger, to: :Rails
-      attr_reader :url
-      def initialize(url)
+      attr_reader :url, :cache_path
+      def initialize(url, options = {})
         @url = url 
+        @cache_path = options[:cache_path]
       end
 
       def fetch
@@ -42,13 +46,13 @@ def ext
       end
 
       def file_name
-        @cache_file_name ||= ::File.join(HTTPFileResolver.cache_path, Digest::MD5.hexdigest(url)+"#{ext}")
+        @cache_file_name ||= ::File.join(cache_path, Digest::MD5.hexdigest(url)+"#{ext}")
       end
 
       def download_file
         ensure_cache_path(::File.dirname(file_name))
         benchmark ("Riiif downloaded #{url}") do
-          ::File.atomic_write(file_name, HTTPFileResolver.cache_path) do |local| 
+          ::File.atomic_write(file_name, cache_path) do |local| 
             begin
               Kernel::open(url) do |remote|
                 while chunk = remote.read(8192)
@@ -71,7 +75,7 @@ def ensure_cache_path(path)
 
     protected
 
-      def self.uri(id)
+      def uri(id)
         raise "Must set the id_to_uri lambda" if id_to_uri.nil?
         id_to_uri.call(id)
       end

spec/models/file_system_file_resolver_spec.rb

@@ -1,13 +1,13 @@
 require 'spec_helper'
 
 describe Riiif::FileSystemFileResolver do
-  subject { Riiif::FileSystemFileResolver }
+  subject { Riiif::FileSystemFileResolver.new }
   it "should raise an error when the file isn't found" do
     expect{subject.find('1234')}.to raise_error Riiif::ImageNotFoundError
   end
 
   it "should get the jpeg2000 file" do
-    expect(subject.find('world').path).to eq Riiif::FileSystemFileResolver.root + '/spec/samples/world.jp2'
+    expect(subject.find('world').path).to eq subject.root + '/spec/samples/world.jp2'
   end
 
   it "should accept ids with dashes" do

spec/models/http_file_resolver_spec.rb

@@ -1,12 +1,10 @@
 require 'spec_helper'
 
 describe Riiif::HTTPFileResolver do
-  subject { Riiif::HTTPFileResolver }
-  around do |example|
-    old_value = Riiif::HTTPFileResolver.id_to_uri
-    Riiif::HTTPFileResolver.id_to_uri = lambda {|id| id}
-    example.run
-    Riiif::HTTPFileResolver.id_to_uri = old_value
+  subject { Riiif::HTTPFileResolver.new }
+
+  before do
+    subject.id_to_uri = lambda {|id| id}
   end
 
   it "should raise an error when the file isn't found" do

spec/models/image_spec.rb

@@ -33,13 +33,13 @@
 
   context "using HTTPFileResolver" do
     before do
-      Riiif::Image.file_resolver = Riiif::HTTPFileResolver
-      Riiif::HTTPFileResolver.id_to_uri = lambda do |id|
+      Riiif::Image.file_resolver = Riiif::HTTPFileResolver.new
+      Riiif::Image.file_resolver.id_to_uri = lambda do |id|
         "http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/#{id}.jpg/600px-#{id}.jpg"
       end
     end
     after do
-      Riiif::Image.file_resolver = Riiif::FileSystemFileResolver
+      Riiif::Image.file_resolver = Riiif::FileSystemFileResolver.new
     end
 
     describe "get info" do