Extracted storage of files functionality from controller to an object called FileYard.

There is one file yard per web.

app/models/file_yard.rb

@@ -0,0 +1,43 @@
+require 'instiki_errors'
+
+class FileYard
+
+  attr_reader :files_path
+
+  def initialize(files_path)
+    @files_path = files_path
+    @files = Dir["#{files_path}/*"].collect{|path| File.basename(path) if File.file?(path) }.compact
+  end
+
+  def upload_file(name, io)
+    sanitize_file_name(name)
+    if io.kind_of?(Tempfile)
+      io.close
+      FileUtils.mv(io.path, file_path(name))
+    else
+      File.open(file_path(name), 'wb') { |f| f.write(io.read) }
+    end
+  end
+
+  def files
+    Dir["#{files_path}/*"].collect{|path| File.basename(path) if File.file?(path)}.compact
+  end
+
+  def has_file?(name)
+    files.include?(name)
+  end
+
+  def file_path(name)
+    "#{files_path}/#{name}"
+  end
+
+  SANE_FILE_NAME = /[-_\.A-Za-z0-9]{1,255}/
+
+  def sanitize_file_name(name)
+    unless name =~ SANE_FILE_NAME
+      raise Instiki::ValidationError.new("Invalid file name: '#{name}'.\n" +
+            "Only latin characters, digits, dots, underscores and dashes are accepted.")
+    end
+  end
+
+end