Image tag policy

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 - Do not modify original url when using cdn
 
+### features
+
+- filepicker_image_tag now works with policies
+
 ## 1.1.0 (March 30, 2014)
 
 ### features

README.md

@@ -158,7 +158,35 @@ of an iframe on the page.
 * services - What services your users can upload to. Ex: "BOX, COMPUTER, FACEBOOK".
 * save_as_name - A recommended file name. The user can override this.
 
-### Demo
+### Policy
+
+To use the [filepicker policies](https://developers.inkfilepicker.com/docs/security/) follow this instructions.
+
+Set your Secret Key in `config/application.rb`
+
+```ruby
+config.filepicker_rails.secret_key = "Your filepicker.io Secret Key"
+```
+
+### Expiry time
+
+By default the expiry time is 10 minutes. If you need to change the expiry time this should be an integer and it is expressed in seconds since the [Epoch](http://en.wikipedia.org/wiki/Unix_time).
+
+So you can do something like that to set the expiry time to 5 minutes.
+
+```ruby
+config.filepicker_rails.expiry = -> { (Time.zone.now + 5.minutes).to_i }
+```
+
+If you need always the same url, a static expiry time, to do some cache. You can set a date starting of the Epoch.
+
+```ruby
+-> { 100.years.since(Time.at(0)).to_i }
+```
+
+The argument need to be a [callable](http://www.rubytapas.com/episodes/35-Callable).
+
+## Demo
 
 See a simple demo app [repo](https://github.com/maxtilford/filepicker-rails-demo)
 

app/helpers/filepicker_rails/application_helper.rb

@@ -73,18 +73,66 @@ def filepicker_image_tag(url, image_options={}, image_tag_options={})
     #                 and horizontal with a comma. The default behavior
     #                 is bottom,right
     def filepicker_image_url(url, options = {})
-      query_params = options.slice(:w, :h, :fit, :align, :rotate, :cache, :crop, :format, :quality, :watermark, :watersize, :waterposition).to_query
+      FilepickerImageUrl.new(url, options).execute
+    end
+
+    class FilepickerImageUrl
 
-      if ::Rails.application.config.filepicker_rails.cdn_host
-        uri = URI.parse(url)
-        url = url.gsub("#{uri.scheme}://#{uri.host}", ::Rails.application.config.filepicker_rails.cdn_host)
+      CONVERT_OPTIONS = [:w, :h, :fit, :align, :rotate, :crop, :format,
+                         :quality, :watermark, :watersize, :waterposition]
+      VALID_OPTIONS   = CONVERT_OPTIONS + [:cache]
+
+      def initialize(url, options = {})
+        @url, @options = url, options
       end
 
-      if query_params.blank?
-        url
-      else
-        [url, "/convert?", query_params].join
+      def execute
+        url_with_path = if convert_options.any?
+          "#{cdn_url}/convert"
+        else
+          cdn_url
+        end
+
+        query_params = all_options.merge(policy_config).to_query
+
+        [url_with_path, query_params.presence].compact.join('?')
       end
+
+      private
+
+        attr_reader :url, :options
+
+        def all_options
+          options.select { |option| VALID_OPTIONS.include?(option) }
+        end
+
+        def convert_options
+          options.select { |option| CONVERT_OPTIONS.include?(option) }
+        end
+
+        def cdn_host
+          ::Rails.application.config.filepicker_rails.cdn_host
+        end
+
+        def cdn_url
+          if cdn_host
+            uri = URI.parse(url)
+            url.gsub("#{uri.scheme}://#{uri.host}", cdn_host)
+          else
+            url
+          end
+        end
+
+        def policy_config
+          return {} unless ::Rails.application.config.filepicker_rails.secret_key.present?
+          grant = Policy.new
+          grant.call = [:read, :convert]
+
+          {
+            'policy' => grant.policy,
+            'signature' => grant.signature
+          }
+        end
     end
   end
 end

filepicker_rails.gemspec

@@ -20,7 +20,7 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency 'coveralls'
   s.add_development_dependency 'sqlite3'
-  s.add_development_dependency 'rspec-rails'
+  s.add_development_dependency 'rspec-rails', '2.99'
   s.add_development_dependency 'timecop'
   s.add_development_dependency 'appraisal'
   s.add_development_dependency 'capybara'

lib/filepicker_rails/configuration.rb

@@ -1,14 +1,19 @@
 module FilepickerRails
   class Configuration
-    attr_writer :api_key, :default_expiry
+    attr_writer :api_key
     attr_accessor :secret_key, :cdn_host
 
     def api_key
       @api_key or raise "Set config.filepicker_rails.api_key"
     end
 
-    def default_expiry
-      @default_expiry ||= 600
+    def expiry=(expiry)
+      raise ArgumentError, 'Must be a callable' unless expiry.respond_to?(:call)
+      @expiry = expiry
+    end
+
+    def expiry
+      @expiry ||= -> { Time.zone.now.to_i + 600 }
     end
   end
 end

lib/filepicker_rails/policy.rb

@@ -23,7 +23,7 @@ def signature
     def json_policy
       hash = Hash.new
 
-      @expiry ||= Time.now.to_i + ::Rails.application.config.filepicker_rails.default_expiry
+      @expiry ||= ::Rails.application.config.filepicker_rails.expiry.call
 
       [:expiry, :call, :handle, :maxsize, :minsize, :path].each do |input|
         hash[input] = send(input) unless send(input).nil?

spec/helpers/aplication_helper_spec.rb → spec/helpers/application_helper_spec.rb

@@ -122,9 +122,6 @@
         expect(filepicker_image_url("foo", rotate: 'exif')).to eq('foo/convert?rotate=exif')
       end
 
-      it "have correct url with 'cache'" do
-        expect(filepicker_image_url("foo", cache: true)).to eq('foo/convert?cache=true')
-      end
 
       it "have correct url with 'crop'" do
         expect(filepicker_image_url("foo", crop: '20,30,400,200')).to eq('foo/convert?crop=20%2C30%2C400%2C200')
@@ -150,6 +147,18 @@
       it "have correct url with 'waterposition'" do
         expect(filepicker_image_url("foo", waterposition: 'top')).to eq('foo/convert?waterposition=top')
       end
+
+      describe 'cache' do
+
+        it "have correct url with 'cache' only" do
+          expect(filepicker_image_url("foo", cache: true)).to eq('foo?cache=true')
+        end
+
+        it "have correct url with 'cache' and convert option" do
+          url = 'foo/convert?align=faces&cache=true'
+          expect(filepicker_image_url("foo", cache: true, align: 'faces')).to eq(url)
+        end
+      end
     end
 
     context "with cdn host" do
@@ -172,5 +181,32 @@
         end.to_not change { url }
       end
     end
+
+    context 'with policy' do
+
+      before do
+        Timecop.freeze(Time.zone.parse("2012-09-19 12:59:27"))
+        Rails.application.config.filepicker_rails.secret_key = 'filepicker123secretkey'
+      end
+
+      after do
+        Timecop.return
+        Rails.application.config.filepicker_rails.secret_key = nil
+      end
+
+      it 'have policy and signature' do
+        url = 'foo?policy=eyJleHBpcnkiOjEzNDgwNjAxNjcsImNhbGwiOlsicmVhZCIsImNvbnZlcnQiXX0%3D' \
+              '&signature=4562a7e728aa0e53d82c20a97e4f01103dd127724edce631c3f4ada70922eecd'
+        expect(filepicker_image_url('foo')).to eq(url)
+      end
+
+      it 'have policy and signature when have some convert option' do
+        url = 'foo/convert' \
+              '?policy=eyJleHBpcnkiOjEzNDgwNjAxNjcsImNhbGwiOlsicmVhZCIsImNvbnZlcnQiXX0%3D' \
+              '&quality=80' \
+              '&signature=4562a7e728aa0e53d82c20a97e4f01103dd127724edce631c3f4ada70922eecd'
+        expect(filepicker_image_url('foo', quality: 80)).to eq(url)
+      end
+    end
   end
 end

spec/lib/configuration_spec.rb

@@ -20,10 +20,16 @@
     end
   end
 
-  describe "#default_expiry=" do
+  describe "#expiry=" do
 
-    it "respond to default_expiry=" do
-      expect(configuration).to respond_to(:default_expiry=)
+    it "respond to expiry=" do
+      expect(configuration).to respond_to(:expiry=)
+    end
+
+    it 'raises error if not receive a callable' do
+      expect do
+        configuration.expiry = 12
+      end.to raise_error(ArgumentError, 'Must be a callable')
     end
   end
 
@@ -49,15 +55,17 @@
     end
   end
 
-  describe "#default_expiry" do
+  describe "#expiry" do
 
     it "have defined value" do
-      configuration.default_expiry = 450
-      expect(configuration.default_expiry).to eq(450)
+      configuration.expiry = -> { 450 }
+      expect(configuration.expiry.call).to eq(450)
     end
 
     it "have a default value" do
-      expect(configuration.default_expiry).to eq(600)
+      Timecop.freeze(Time.zone.parse("2012-09-19 12:59:27")) do
+        expect(configuration.expiry.call).to eq(1348060167)
+      end
     end
   end