rich text embedded images now included in eportfolio zip file

When an ePortfolio page has a rich text section with an embedded
image, the image appears as a seperate file in the .zip download and
appears inline in the page's html file.  Because of this, an
ePortfolio user will be able to embed images in rich text sections.

fixes CNVS-21702

test plan:
- Have (or upload) an image stored in the Files page
- Create a new ePortfolio
- Click on the default Welcome page and then click on Edit This Page
- Select Rich Text Content from the Add Content menu
- In the editor, embed your image from your Canvas files
- Click "Save Page"
- Return to the ePortfolio main page via the navagation breadcrumbs
- Click "Download the contents of this ePortfolio as a zip file"
- Unzip the downloaded zip file and observe that the image is there
  along with Home_Welcome.html.
- Open the "Home_Welcome.html" file in a web browser.
- Observe the image inline on the page.

Change-Id: I0638df03d94eab3e37eb91b9daeb898c20cc42d5
Reviewed-on: https://gerrit.instructure.com/61159
Tested-by: Jenkins
Reviewed-by: Dylan Ross <dross@instructure.com>
Reviewed-by: Cody Poll <cpoll@instructure.com>
QA-Review: Jason Carter <jcarter@instructure.com>
Product-Review: Christi Wruck

app/views/eportfolios/_page_section_static.html.erb

@@ -9,9 +9,9 @@
         <div style="text-align: center;" class="attachment">
           <% attachment = @static_attachments.find{|a| a.id == page_section["attachment_id"]} %>
           <% if attachment && attachment.content_type.match(/\Aimage/) %>
-            <a href="<%= attachment.filename %>"><img src="<%= attachment.filename %>" alt="<%= attachment.filename %>"/></a>
+            <a href="<%= attachment.unencoded_filename %>"><img src="<%= attachment.unencoded_filename %>" alt="<%= attachment.unencoded_filename %>"/></a>
           <% elsif attachment %>
-            <a href="<%= attachment.filename %>">
+            <a href="<%= attachment.unencoded_filename %>">
               <%= t('links.download_attachment', "Click here to Download *%{attachment}*",
                     :attachment => attachment.display_name,
                     :wrapper => '<span class="filename">\1</span>') %>
@@ -35,7 +35,7 @@
             <% submission.attachments.each do |a| %>
               <% attachment = @static_attachments.find{|att| att.id == a.id } %>
               <% if attachment %>
-                <li><a href="<%= attachment.filename %>">
+                <li><a href="<%= attachment.unencoded_filename %>">
                   <%= t('links.download_attachment', "Click here to Download *%{attachment}*",
                         :attachment => a.display_name,
                         :wrapper => '<span class="filename">\1</span>') %>

lib/content_zipper.rb

@@ -100,21 +100,41 @@ class ContentZipper
     ContentZipper.new.zip_eportfolio(*args)
   end
 
-  StaticAttachment = Struct.new(:display_name,
-                                :filename,
-                                :content_type,
-                                :uuid,
-                                :id,
-                                :attachment)
+  class StaticAttachment
+    attr_accessor :display_name, :filename, :unencoded_filename,
+                  :content_type, :uuid, :id, :attachment
+
+    # Match on /files URLs capturing the object id.
+    FILES_REGEX = %r{/files/(?<obj_id>\d+)/\w+(?:(?:[^\s"<'\?\/]*)([^\s"<']*))?}
+
+    def initialize(attachment, idx = nil)
+      @attachment = attachment
+
+      @display_name = @attachment.display_name
+      @filename = idx ? "#{idx}_#{@attachment.filename}" : @attachment.filename
+      @unencoded_filename = idx ? "#{idx}_#{@attachment.unencoded_filename}" : @attachment.unencoded_filename
+      @content_type = @attachment.content_type
+      @uuid = @attachment.uuid
+      @id = @attachment.id
+    end
+  end
 
   def zip_eportfolio(zip_attachment, portfolio)
     static_attachments = []
+    rich_text_attachments = []
     submissions = []
-    portfolio.eportfolio_entries.each do |entry|
+
+    portfolio_entries = portfolio.eportfolio_entries
+
+    idx = 1
+    portfolio_entries.each do |entry|
+      entry.readonly!
+
+      idx = rewrite_eportfolio_richtext_entry(idx, rich_text_attachments, entry)
       static_attachments += entry.attachments
       submissions += entry.submissions
     end
-    idx = 1
+
     submissions_hash = {}
     submissions.each do |s|
       submissions_hash[s.id] = s
@@ -124,30 +144,27 @@ class ContentZipper
       end
     end
     static_attachments = static_attachments.uniq.map do |a|
-      obj = StaticAttachment.new
-      obj.display_name = a.display_name
-      obj.filename = "#{idx}_#{a.filename}"
-      obj.content_type = a.content_type
-      obj.uuid = a.uuid
-      obj.id = a.id
-      obj.attachment = a
+      obj = StaticAttachment.new(a, idx)
       idx += 1
       obj
     end
+
+    all_attachments = rich_text_attachments + static_attachments
+
     filename = portfolio.name
     make_zip_tmpdir(filename) do |zip_name|
       idx = 0
-      count = static_attachments.length + 2
+      count = all_attachments.length + 2
       Zip::File.open(zip_name, Zip::File::CREATE) do |zipfile|
         update_progress(zip_attachment, idx, count)
-        portfolio.eportfolio_entries.each do |entry|
+        portfolio_entries.each do |entry|
           filename = "#{entry.full_slug}.html"
-          content = render_eportfolio_page_content(entry, portfolio, static_attachments, submissions_hash)
+          content = render_eportfolio_page_content(entry, portfolio, all_attachments, submissions_hash)
           zipfile.get_output_stream(filename) {|f| f.puts content }
         end
         update_progress(zip_attachment, idx, count)
-        static_attachments.each do |a|
-          add_attachment_to_zip(a.attachment, zipfile, a.filename)
+        all_attachments.each do |a|
+          add_attachment_to_zip(a.attachment, zipfile, a.unencoded_filename)
           update_progress(zip_attachment, idx, count)
         end
         content = File.open(Rails.root.join('public', 'images', 'logo.png'), 'rb').read rescue nil
@@ -170,6 +187,31 @@ class ContentZipper
     res
   end
 
+  def rewrite_eportfolio_richtext_entry(idx, attachments, entry)
+    # In each rich_text section, find any referenced images, replace
+    # the text with the image name, and add the image to the
+    # attachments to be downloaded. If the rich_text attachment
+    # can't be found, don't modify the the HTML, live with the
+    # broken link, but have a mostly correct zip file.
+    #
+    # All other attachments toss on the static attachment pile for
+    # later processing.
+    entry.content.select { |c| c[:section_type] == "rich_text" }.each do |rt|
+      rt[:content].gsub!(StaticAttachment::FILES_REGEX) do |match|
+        att = Attachment.find_by_id(Regexp.last_match(:obj_id))
+        if att.nil?
+          match
+        else
+          sa = StaticAttachment.new(att, idx)
+          attachments << sa
+          idx += 1
+          sa.unencoded_filename
+        end
+      end
+    end
+    return idx
+  end
+
   def self.zip_base_folder(*args)
     ContentZipper.new.zip_base_folder(*args)
   end