Restructuring the handling for UV URLs

app/helpers/application_helper.rb

@@ -60,4 +60,41 @@ def document_thumbnail(document, image_options = {})
     url = values.first
     image_tag url, image_options if url.present?
   end
+
+  # Generate the URL for the Universal Viewer to view the content for the
+  # document manifest
+  # @return [String]
+  def universal_viewer_url
+    universal_viewer.url
+  end
+
+  private
+
+    # Access the base URL for the UV installation
+    # @return [String]
+    def universal_viewer_url_base
+      "https://figgy-staging.princeton.edu"
+    end
+
+    # Generate the URL for the configuration for the UV
+    # @return [String]
+    def universal_viewer_config_url
+      "#{universal_viewer_url_base}/viewer/exhibit/config?manifest=#{@document.manifest}"
+    end
+
+    # Generate the URL for the UV viewer
+    # @return [String]
+    def universal_viewer_instance_url
+      "#{universal_viewer_url_base}/uv/uv"
+    end
+
+    # Construct the object used to handle Universal Viewer installations
+    # @return [UniversalViewer]
+    def universal_viewer
+      UniversalViewer.new(
+        universal_viewer_instance_url,
+        manifest: @document.manifest,
+        config: universal_viewer_config_url
+      )
+    end
 end

app/values/universal_viewer.rb

@@ -0,0 +1,29 @@
+
+# Class modeling URLs for Universal Viewer installations
+class UniversalViewer
+
+  # Constructor
+  # @param base_url [String] URL to the installation
+  # @param uv_params [Hash] GET parameters to pass to the URL
+  def initialize(base_url, **uv_params)
+    @base_url = base_url
+    @params = uv_params
+  end
+
+  # Generate the string representation of the URL
+  # @return [String]
+  def url
+    components = [@base_url.to_s]
+
+    components << "#?" unless @params.empty?
+
+    params = []
+    @params.each_pair do |name, value|
+      params << "#{name.to_s}=#{CGI::escape(value)}"
+    end
+    components += [params.join('&')]
+
+    components.join
+  end
+end
+

app/views/catalog/_universal_viewer_default.html.erb

@@ -1,5 +1,4 @@
 <div class="uv__overlay">
-  <iframe allowFullScreen="true" src="https://figgy-staging.princeton.edu/uv/uv#?manifest=<%= document.manifest %>&config=<%= CGI::escape("https://figgy-staging.princeton.edu/viewer/exhibit/config?manifest=#{document.manifest}") %>">
-  </iframe>
-  <%= link_to image_tag("iiif.png", class: "logo", alt: "IIIF Drag and Drop"), viewers_page_path(manifest: document.manifest, format: :html) %>
+  <iframe allowfullscreen="true" src="<%= universal_viewer_url %>"></iframe>
+  <%= link_to image_tag("iiif.png", class: "logo", alt: "IIIF Drag and Drop"), universal_viewer_url %>
 </div>