From: Michael Orlitzky <michael@orlitzky.com>
Date: Sun, 27 Sep 2009 04:52:46 +0000 (-0400)
Subject: Added configurable downloaders.
X-Git-Url: http://gitweb.michael.orlitzky.com/?p=dead%2Fwhatever-dl.git;a=commitdiff_plain;h=e3eeb8df887fc68959ab7d7ebae5c0206b79c230

Added configurable downloaders.
Created three new classes: Downloader, OpenUriDownloader, and WgetDownloader.
Created a configuration file.
Modified whatever-dl to use the configuration information.
---

diff --git a/bin/configuration.rb b/bin/configuration.rb
new file mode 100644
index 0000000..ad942c7
--- /dev/null
+++ b/bin/configuration.rb
@@ -0,0 +1,12 @@
+module Configuration
+  # Configurable Options
+
+  # We support a couple of different download methods. The :openuri
+  # method utilizes the ruby open-uri library, and provides its own
+  # progress bar with no external dependencies. The :wget method, on the
+  # other hand, requires GNU Wget (http://www.gnu.org/software/wget/),
+  # but will support auto-resume of partially-downloaded files for
+  # example.
+  DOWNLOAD_METHOD = :openuri
+  #DOWNLOAD_METHOD = :wget
+end
diff --git a/bin/whatever-dl b/bin/whatever-dl
index 9a6b8c3..fbc84e9 100755
--- a/bin/whatever-dl
+++ b/bin/whatever-dl
@@ -31,10 +31,11 @@ require 'pathname'
 executable = Pathname.new(__FILE__).realpath.to_s
 $: << File.dirname(executable) + '/../'
 
-# We require the UriUtilities class to handle
-# the download of the video URL.
-require 'src/uri_utilities'
+# Load our config file.
+require 'bin/configuration'
 
+# And the downloaders...
+require 'src/downloader'
 
 # The Dir.glob that's coming up doesn't use the
 # Ruby library path so we need to tell it where to
@@ -82,23 +83,22 @@ if (__FILE__ == $0) then
     puts 'Error retrieving video URL.'
     exit(EXIT_COULDNT_GET_VIDEO_URL)
   end
-
-  video_uri = URI.parse(video_url)
-  uu = UriUtilities.new()
-  
+    
   if File.exists?(site.get_video_filename())
     puts "Error: output file already exists. Please remove #{site.get_video_filename()}, and try again."
     Kernel.exit(EXIT_OUTPUT_FILE_ALREADY_EXISTS)
   end
 
-
+  # The Downloader class is a factory; it should decide
+  # which subclass we get.
+  downloader = Downloader.create(Configuration::DOWNLOAD_METHOD)
+  
   # Attempt to download the file, and rescue and report
-  # any (predictable) exceptions.
+  # any (predictable) exceptions. The wget downloader will
+  # naturally not report any of these, since it will die in
+  # its own process.
   begin
-    puts "Fetching #{video_url}"
-    puts "Saving as #{site.get_video_filename()}."
-    puts ""
-    uu.download_with_progress_bar(video_uri, site.get_video_filename())
+    downloader.download(video_url, site.get_video_filename())
   rescue Errno::ECONNREFUSED => e
     puts 'The connection to the server (to download the video file) was refused. Check your connection, and try again later.'
     Kernel.exit(EXIT_CONNECTION_REFUSED)
@@ -110,7 +110,7 @@ if (__FILE__ == $0) then
   end
 
   # Write an empty line at the end for aesthetic reasons.
-  puts ""
+  puts ''
   
   Kernel.exit(EXIT_SUCCESS)
 end
diff --git a/src/downloader.rb b/src/downloader.rb
new file mode 100644
index 0000000..eac7c18
--- /dev/null
+++ b/src/downloader.rb
@@ -0,0 +1,42 @@
+#
+# Copyright Michael Orlitzky
+#
+# http://michael.orlitzky.com/
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# http://www.fsf.org/licensing/licenses/gpl.html
+#
+
+class Downloader
+
+  def self.create(download_method)
+    # Return the subclass corresponding to download_method.
+    case download_method
+    when :openuri
+      return OpenUriDownloader.new()
+    when :wget
+      return WgetDownloader.new()
+    end
+  end
+
+  
+  # Abstract
+  def download(url, outfile)
+    raise NotImplementedError
+  end
+  
+end
+
+
+# This is wacky, but seems to work.
+require 'src/wget_downloader'
+require 'src/open_uri_downloader'
diff --git a/src/open_uri_downloader.rb b/src/open_uri_downloader.rb
new file mode 100644
index 0000000..44ea037
--- /dev/null
+++ b/src/open_uri_downloader.rb
@@ -0,0 +1,33 @@
+#
+# Copyright Michael Orlitzky
+#
+# http://michael.orlitzky.com/
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# http://www.fsf.org/licensing/licenses/gpl.html
+#
+
+require 'src/uri_utilities'
+
+class OpenUriDownloader < Downloader
+
+  def download(url, outfile)
+    uri = URI.parse(url)
+    
+    uu = UriUtilities.new()
+    puts "Fetching #{url}"
+    puts "Saving as #{outfile}."
+    puts ''
+    uu.download_with_progress_bar(uri, outfile)
+  end
+  
+end
diff --git a/src/wget_downloader.rb b/src/wget_downloader.rb
new file mode 100644
index 0000000..2cbdd45
--- /dev/null
+++ b/src/wget_downloader.rb
@@ -0,0 +1,26 @@
+#
+# Copyright Michael Orlitzky
+#
+# http://michael.orlitzky.com/
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# http://www.fsf.org/licensing/licenses/gpl.html
+#
+
+class WgetDownloader < Downloader
+
+  def download(url, outfile)
+    # This one's easy.
+    Kernel.exec("wget -O \"#{outfile}\" \"#{url}\"")
+  end
+  
+end