Allow filter parameters to be passed "URI style"

docs/filters.html

@@ -32,12 +32,19 @@ types of advertisements that you may find in feeds.</p>
 the form of a <code>planet:excerpt</code> element) to the feed itself.  You
 can see examples of how parameters are passed to this program in either
 <a href="../tests/data/filter/excerpt-images.ini">excerpt-images</a> or 
-<a href="../examples/opml-top100.ini">opml-top100.ini</a>.</p>
+<a href="../examples/opml-top100.ini">opml-top100.ini</a>.
+Alternately parameters may be passed
+<abbr title="Uniform Resource Identifier">URI</abbr> style, for example: 
+<a href="../tests/data/filter/excerpt-images2.ini">excerpt-images2</a>.
+</p>
 
 <p>The <a href="../filters/xpath_sifter.py">xpath sifter</a> is a variation of
 the above, including or excluding feeds based on the presence (or absence) of
 data specified by <a href="http://www.w3.org/TR/xpath20/">xpath</a>
-expressions.</p>
+expressions.  Again, parameters can be passed as
+<a href="../tests/data/filter/xpath-sifter.ini">config options</a> or 
+<a href="../tests/data/filter/xpath-sifter2.ini">URI style</a>.
+</p>
 
 <h3>Notes</h3>
 

planet/shell/__init__.py

@@ -13,6 +13,14 @@ def run(template_file, doc, mode='template'):
     else:
         dirs = planet.config.filter_directories()
  
+    # parse out "extra" options
+    if template_file.find('?') < 0:
+        extra_options = {}
+    else:
+        import cgi
+        template_file, extra_options = template_file.split('?',1)
+        extra_options = dict(cgi.parse_qsl(extra_options))
+
     # see if the template can be located
     for template_dir in dirs:
         template_resolved = os.path.join(template_dir, template_file)
@@ -43,6 +51,7 @@ def run(template_file, doc, mode='template'):
 
     # Execute the shell module
     options = planet.config.template_options(template_file)
+    options.update(extra_options)
     log.debug("Processing %s %s using %s", mode,
         os.path.realpath(template_resolved), module_name)
     if mode == 'filter':

tests/data/filter/excerpt-images2.ini

@@ -0,0 +1,2 @@
+[Planet]
+filters = excerpt.py?omit=img

tests/data/filter/xpath-sifter2.ini

@@ -0,0 +1,2 @@
+[Planet]
+filters = xpath_sifter.py?require=//atom%3Acategory%5B%40term%3D%27two%27%5D

tests/test_filters.py

@@ -14,10 +14,16 @@ class FilterTests(unittest.TestCase):
         imgsrc = dom.getElementsByTagName('img')[0].getAttribute('src')
         self.assertEqual('http://example.com.nyud.net:8080/foo.png', imgsrc)
 
-    def test_excerpt_images(self):
+    def test_excerpt_images1(self):
-        testfile = 'tests/data/filter/excerpt-images.xml'
         config.load('tests/data/filter/excerpt-images.ini')
+        self.verify_images()
 
+    def test_excerpt_images2(self):
+        config.load('tests/data/filter/excerpt-images2.ini')
+        self.verify_images()
+
+    def verify_images(self):
+        testfile = 'tests/data/filter/excerpt-images.xml'
         output = open(testfile).read()
         for filter in config.filters():
             output = shell.run(filter, output, mode="filter")
@@ -58,8 +64,15 @@ class FilterTests(unittest.TestCase):
         self.assertEqual(u'before--after',
             excerpt.firstChild.firstChild.nodeValue)
 
-    def test_xpath_filter(self):
+    def test_xpath_filter1(self):
         config.load('tests/data/filter/xpath-sifter.ini')
+        self.verify_xpath()
+
+    def test_xpath_filter2(self):
+        config.load('tests/data/filter/xpath-sifter2.ini')
+        self.verify_xpath()
+
+    def verify_xpath(self):
         testfile = 'tests/data/filter/category-one.xml'
 
         output = open(testfile).read()
@@ -89,7 +102,8 @@ try:
         import libxml2
     except:
         logger.warn("libxml2 is not available => can't test xpath_sifter")
-        del FilterTests.test_xpath_filter
+        del FilterTests.test_xpath_filter1
+        del FilterTests.test_xpath_filter2
 
 except ImportError:
     logger.warn("Popen is not available => can't test standard filters")