# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1342477448 -7200
# Node ID f1b4f05a4801571e762c5b031f08b327141c4db9
# Parent  4e984fd40300484ed4e4e4f25021475a86a8ad5a
Added remote resource management from EventAggregator.

diff -r 4e984fd40300 -r f1b4f05a4801 MoinRemoteSupport.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MoinRemoteSupport.py	Tue Jul 17 00:24:08 2012 +0200
@@ -0,0 +1,68 @@
+# -*- coding: iso-8859-1 -*-
+"""
+    MoinMoin - MoinRemoteSupport library
+
+    @copyright: 2011, 2012 by Paul Boddie <paul@boddie.org.uk>
+    @license: GNU GPL (v2 or later), see COPYING.txt for details.
+"""
+
+from MoinMoin.action import cache
+from MoinMoin import caching
+import urllib2
+
+def getCachedResource(request, url, arena, scope, max_cache_age):
+
+    """
+    Using the given 'request', return the resource data for the given 'url',
+    accessing a cache entry with the given 'arena' and 'scope' where the data
+    has already been downloaded. The 'max_cache_age' indicates the length in
+    seconds that a cache entry remains valid.
+    """
+
+    # See if the URL is cached.
+
+    cache_key = cache.key(request, content=url)
+    cache_entry = caching.CacheEntry(request, arena, cache_key, scope=scope)
+
+    # If no entry exists, or if the entry is older than the specified age,
+    # create one with the response from the URL.
+
+    now = time.time()
+    mtime = cache_entry.mtime()
+
+    # NOTE: The URL could be checked and the 'If-Modified-Since' header
+    # NOTE: (see MoinMoin.action.pollsistersites) could be checked.
+
+    if not cache_entry.exists() or now - mtime >= max_cache_age:
+
+        # Access the remote data source.
+
+        cache_entry.open(mode="w")
+
+        try:
+            f = urllib2.urlopen(url)
+            try:
+                cache_entry.write(url + "\n")
+                cache_entry.write((f.headers.get("content-type") or "") + "\n")
+                cache_entry.write(f.read())
+            finally:
+                cache_entry.close()
+                f.close()
+
+        # In case of an exception, just ignore the remote source.
+        # NOTE: This could be reported somewhere.
+
+        except IOError:
+            if cache_entry.exists():
+                cache_entry.remove()
+            continue
+
+    # Open the cache entry and read it.
+
+    cache_entry.open()
+    try:
+        return cache_entry.read()
+    finally:
+        cache_entry.close()
+
+# vim: tabstop=4 expandtab shiftwidth=4
diff -r 4e984fd40300 -r f1b4f05a4801 README.txt
--- a/README.txt	Tue Jul 17 00:01:30 2012 +0200
+++ b/README.txt	Tue Jul 17 00:24:08 2012 +0200
@@ -70,6 +70,8 @@
   * Added a getCurrentTime function to DateSupport.
   * Added parsing/formatting-related functions from EventAggregator and
     ImprovedTableParser to MoinSupport.
+  * Added remote resource management from EventAggregator to
+    MoinRemoteSupport.
 
 Release Procedures
 ------------------