Added file extension to logo in start page to show logo also in IE 11.

db/migrate/20150713000001_update_logo.rb

@@ -0,0 +1,8 @@
+class UpdateLogo < ActiveRecord::Migration
+  def up
+
+    return if !Setting.find_by(name: 'product_logo')
+    StaticAssets.read
+    StaticAssets.sync
+  end
+end

lib/static_assets.rb

@@ -1,6 +1,19 @@
 module StaticAssets
 
-  def self.data_url_attributes( data_url )
+=begin
+
+  file_attributes = StaticAssets.data_url_attributes(data_url)
+
+returns
+
+  {
+    mime_type: 'image/png',
+    content: image_bin_content,
+  }
+
+=end
+
+  def self.data_url_attributes(data_url)
     data = {}
     if data_url =~ /^data:(.+?);base64,(.+?)$/
       data[:mime_type] = $1
@@ -10,73 +23,141 @@ module StaticAssets
     fail "Unable to parse data url: #{data_url.substr(0, 100)}"
   end
 
-  # store image 1:1
-  def self.store_raw( content, content_type )
-    Store.remove( object: 'System::Logo', o_id: 1 )
-    Store.add(
+=begin
+
+store image 1:1 in backend and return filename
+
+  filename = StaticAssets.store_raw( content, content_type )
+
+returns
+
+  filename # hash.png
+
+=end
+
+  def self.store_raw(content, content_type)
+    Store.remove(object: 'System::Logo', o_id: 1)
+    file = Store.add(
       object: 'System::Logo',
       o_id: 1,
       data: content,
-      filename: 'image',
+      filename: 'logo_raw',
       preferences: {
         'Content-Type' => content_type
       },
     )
-    Digest::MD5.hexdigest( content )
+    filename(file)
   end
 
-  # read raw 1:1
+=begin
+
+read image 1:1 size in backend and return file (Store model)
+
+  store = StaticAssets.read_raw
+
+returns
+
+  store # Store model, e.g. store.content or store.preferences
+
+=end
+
   def self.read_raw
-    list = Store.list( object: 'System::Logo', o_id: 1 )
+    list = Store.list(object: 'System::Logo', o_id: 1)
     if list && list[0]
       return Store.find( list[0] )
     end
     fail 'No such raw logo!'
   end
 
-  # store image in right size
-  def self.store( content, content_type )
-    Store.remove( object: 'System::Logo', o_id: 2 )
-    Store.add(
+=begin
+
+store image in right size (resized) in backend and return filename
+
+  filename = StaticAssets.store( content, content_type )
+
+returns
+
+  filename # hash.png
+
+=end
+
+  def self.store(content, content_type)
+    Store.remove(object: 'System::Logo', o_id: 2)
+    file = Store.add(
       object: 'System::Logo',
       o_id: 2,
       data: content,
-      filename: 'image',
+      filename: 'logo',
       preferences: {
         'Content-Type' => content_type
       },
     )
     StaticAssets.sync
-    Digest::MD5.hexdigest( content )
+    filename(file)
   end
 
-  # read image
+=begin
+
+read image size from backend (if not exists, read 1:1 size) and return file (Store model)
+
+  store = StaticAssets.read
+
+returns
+
+  store # Store model, e.g. store.content or store.preferences
+
+=end
+
   def self.read
 
     # use reduced dimensions
-    list = Store.list( object: 'System::Logo', o_id: 2 )
+    list = Store.list(object: 'System::Logo', o_id: 2)
 
     # as fallback use 1:1
     if !list || !list[0]
-      list = Store.list( object: 'System::Logo', o_id: 1 )
+      list = Store.list(object: 'System::Logo', o_id: 1)
     end
 
     # store hash in config
     if list && list[0]
-      file = Store.find( list[0] )
-      hash = Digest::MD5.hexdigest( file.content )
-      Setting.set('product_logo', hash)
+      file = Store.find(list[0])
+      filelocation = filename(file)
+      Setting.set('product_logo', filelocation)
       return file
     end
   end
 
-  # sync image to fs
+=begin
+
+generate filename based on Store model
+
+  filename = StaticAssets.filename(store)
+
+=end
+
+  def self.filename(file)
+    hash = Digest::MD5.hexdigest(file.content)
+    extention = ''
+    if file.preferences['Content-Type'] =~ /jpg|jpeg/i
+      extention = '.jpg'
+    elsif file.preferences['Content-Type'] =~ /png/i
+      extention = '.png'
+    end
+    "#{hash}#{extention}"
+  end
+
+=begin
+
+sync image to fs (public/assets/images/hash.png)
+
+  StaticAssets.sync
+
+=end
+
   def self.sync
     file = read
     return if !file
-
-    hash = Digest::MD5.hexdigest( file.content )
-    path = "#{Rails.root}/public/assets/images/#{hash}"
+    path = "#{Rails.root}/public/assets/images/#{filename(file)}"
     File.open( path, 'wb' ) do |f|
       f.puts file.content
     end