show google previews on file show page if supported

Google previews weren't being shown

Test Plan:
 * only enable google docs locally
 * upload a pdf to the course
 * link a module to that file
 * click the module link
 * the file should be previewed with google docs

refs #11219

Change-Id: I75da7ba9fbfbd4051f3d5493a4bbb99c076cddc5
Reviewed-on: https://gerrit.instructure.com/14653
Reviewed-by: Cameron Matheson <cameron@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>

Author: bracken

app/helpers/attachment_helper.rb

@@ -36,6 +36,8 @@ def doc_preview_attributes(attachment, attrs={})
         ErrorReport.log_exception('scribd', e)
       end
     end
+    attrs[:attachment_id] = attachment.id
+    attrs[:mimetype] = attachment.mimetype
     attrs.inject("") { |s,(attr,val)| s << "data-#{attr}=#{val} " }
   end
 end

app/views/files/show.html.erb

@@ -41,9 +41,7 @@
     <span style="font-size: 1.2em;">
       <%= link_to "Download #{@attachment.display_name}", download_url %>
     </span> (<%= @attachment.readable_size %>)
-    <% if @attachment.crocodoc_available? || @attachment.scribdable? %>
-      <div id="doc_preview" <%= doc_preview_attributes(@attachment, :attachment_view_inline_ping_url => context_url(@context, :context_file_inline_view_url, @attachment.id)) %>></div>
-    <% end %>
+    <div id="doc_preview" <%= doc_preview_attributes(@attachment, :attachment_view_inline_ping_url => context_url(@context, :context_file_inline_view_url, @attachment.id)) %>></div>
   <% end %>
 <% end %>
 <%= render :partial => 'shared/sequence_footer', :locals => {:asset => @attachment} %>

public/javascripts/jquery.doc_previews.js

@@ -136,7 +136,7 @@ define([
         }
         // END COPIED SNIPPETT
 
-      } else if (!INST.disableGooglePreviews && (!opts.mimeType || $.isPreviewable(opts.mimeType, 'google')) && opts.attachment_id || opts.public_url){
+      } else if (!INST.disableGooglePreviews && (!opts.mimetype || $.isPreviewable(opts.mimetype, 'google')) && opts.attachment_id || opts.public_url){
         // else if it's something google docs preview can handle and we can get a public url to this document.
         function loadGooglePreview(){
           // this handles both ssl and plain http.
@@ -164,9 +164,9 @@ define([
             }
           });
         }
-      } else {
+      } else if ($.filePreviewsEnabled()) {
         // else fall back with a message that the document can't be viewed inline
-        $this.html('<p>' + htmlEscape(I18n.t('errors.cannot_view_document_inline', 'This document cannot be viewed inline, you might not have permission to view it or it might have been deleted.')) + '</p>');
+        $this.html('<p>' + htmlEscape(I18n.t('errors.cannot_view_document_inline', 'This document cannot be viewed inline.')) + '</p>');
       }
     });
   };