Add version update check.

doc/README.txt

@@ -79,7 +79,7 @@ or if you do not have root permissions:
 
 Dependencies
 -------------
-Python version 2.7 or higher, which can be downloaded
+Python version 2.7.x or Python 3.3 or higher. Both can be downloaded
 from http://www.python.org/
 
 Also the python-requests module is used, which can be downloaded

dosage

@@ -16,11 +16,10 @@ import argparse
 import pydoc
 from io import StringIO
 
-from dosagelib import events, scraper
+from dosagelib import events, scraper, configuration
 from dosagelib.output import out
 from dosagelib.util import internal_error, getDirname, strlimit, getLangName
 from dosagelib.ansicolor import get_columns
-from dosagelib.configuration import App, Freeware, Copyright, SupportUrl
 
 
 class ArgumentParser(argparse.ArgumentParser):
@@ -80,6 +79,7 @@ def setupOptions():
     parser.add_argument('-t', '--timestamps', action='store_true', help='print timestamps for all output at any info level')
     parser.add_argument('-o', '--output', action='append', dest='handler', choices=events.getHandlerNames(), help='sets output handlers for downloaded comics')
     parser.add_argument('--adult', action='store_true', help='confirms that you are old enough to view adult content')
+    # multimatch is only used for development, eg. testing if all comics of a scripted plugin are working
     parser.add_argument('--multimatch', action='store_true', help=argparse.SUPPRESS)
     parser.add_argument('comic', nargs='*', help='comic module name (including case insensitive substrings)')
     try:
@@ -90,12 +90,37 @@ def setupOptions():
     return parser
 
 
-def displayVersion():
+def displayVersion(verbose):
     """Display application name, version, copyright and license."""
-    print(App)
-    print(Copyright)
-    print(Freeware)
-    print("For support see", SupportUrl)
+    print(configuration.App)
+    print(configuration.Copyright)
+    print(configuration.Freeware)
+    print("For support see", configuration.SupportUrl)
+    if verbose:
+        # search for updates
+        from dosagelib.updater import check_update
+        result, value = check_update()
+        if result:
+            if value:
+                version, url = value
+                if url is None:
+                    # current version is newer than online version
+                    text = ('Detected local or development version %(currentversion)s. '
+                            'Available version of %(app)s is %(version)s.')
+                else:
+                    # display update link
+                    text = ('A new version %(version)s of %(app)s is '
+                            'available at %(url)s.')
+                attrs = dict(version=version, app=configuration.AppName,
+                             url=url, currentversion=configuration.Version)
+                print(text % attrs)
+        else:
+            if value is None:
+                value = 'invalid update file syntax'
+            text = ('An error occured while checking for an '
+                    'update of %(app)s: %(error)s.')
+            attrs = dict(error=value, app=configuration.AppName)
+            print(text % attrs)
     return 0
 
 
@@ -196,7 +221,7 @@ def run(options):
     """Execute comic commands."""
     setOutputInfo(options)
     if options.version:
-        return displayVersion()
+        return displayVersion(options.verbose)
     if options.list:
         return doList()
     if options.singlelist:

dosage.freecode

@@ -4,7 +4,7 @@ Release-Focus: Minor feature enhancements
 Hide: N
 Website-URL: http://wummel.github.com/dosage/
 Changelog-URL: https://github.com/wummel/dosage/blob/master/doc/changelog.txt
-Tar/GZ-URL: http://github.com/downloads/wummel/dosage/dosage-${version}.tar.gz
+Source-Package-URL: http://github.com/downloads/wummel/dosage/dosage-${version}.tar.gz
 GIT-Tree-URL: https://github.com/wummel/dosage.git
 Windows-installer-URL: http://github.com/downloads/wummel/dosage/dosage-${version}.exe
 

dosagelib/updater.py

@@ -0,0 +1,58 @@
+# -*- coding: iso-8859-1 -*-
+"""
+Function to check for updates.
+"""
+import os
+from .configuration import Version as CurrentVersion
+from .util import urlopen
+from distutils.version import StrictVersion
+import requests
+
+# Use the Freecode submit file as source since that file gets updated
+# only when releasing a new version.
+UPDATE_URL = "https://raw.github.com/wummel/dosage/master/dosage.freecode"
+VERSION_TAG = 'Version:'
+if os.name == 'nt':
+    URL_TAG = 'Windows-installer-URL:'
+else:
+    URL_TAG = 'Source-Package-URL:'
+
+
+def check_update ():
+    """Return the following values:
+       (False, errmsg) - online version could not be determined
+       (True, None) - user has newest version
+       (True, (version, url string)) - update available
+       (True, (version, None)) - current version is newer than online version
+    """
+    version, value = get_online_version()
+    if version is None:
+        # value is an error message
+        return False, value
+    if version == CurrentVersion:
+        # user has newest version
+        return True, None
+    if is_newer_version(version):
+        # value is an URL linking to the update package
+        return True, (version, value)
+    # user is running a local or development version
+    return True, (version, None)
+
+
+def get_online_version ():
+    """Download update info and parse it."""
+    session = requests.session()
+    page = urlopen(UPDATE_URL, session, stream=False)
+    version, url = None, None
+    for line in page.text.splitlines():
+        if line.startswith(VERSION_TAG):
+            version = line.split(':', 1)[1].strip()
+        elif line.startswith(URL_TAG):
+            url = line.split(':', 1)[1].strip()
+            url = url.replace('${version}', version)
+    return version, url
+
+
+def is_newer_version (version):
+    """Check if given version is newer than current version."""
+    return StrictVersion(version) > StrictVersion(CurrentVersion)