1 files changed, 75 insertions, 0 deletions
diff --git a/paste/wdg_validate.py b/paste/wdg_validate.py
new file mode 100644
index 0000000..b7bdeff
--- /dev/null
+++ b/paste/wdg_validate.py
@@ -0,0 +1,75 @@
+"""
+Middleware that checks HTML and appends messages about the validity of
+the HTML.  Uses: http://www.htmlhelp.com/tools/validator/ -- interacts
+with the command line client.  Use the configuration ``wdg_path`` to
+override the path (default: looks for ``validate`` in $PATH).
+
+To install, in your web context's __init__.py::
+
+    def urlparser_wrap(environ, start_response, app):
+        return wdg_validate.WDGValidateMiddleware(app)(
+            environ, start_response)
+"""
+
+from cStringIO import StringIO
+import subprocess
+from paste import wsgilib
+import re
+import cgi
+
+class WDGValidateMiddleware(object):
+
+    _end_body_regex = re.compile(r'</body>', re.I)
+
+    def __init__(self, app):
+        self.app = app
+
+    def __call__(self, environ, start_response):
+        output = StringIO()
+        response = []
+        def writer_start_response(status, headers):
+            response.extend((status, headers))
+            start_response(status, headers)
+            return output.write
+        app_iter = self.app(environ, writer_start_response)
+        try:
+            for s in app_iter:
+                output.write(s)
+        finally:
+            if hasattr(app_iter, 'close'):
+                app_iter.close()
+        page = output.getvalue()
+        status, headers = response
+        v = wsgilib.header_value(headers, 'content-type')
+        if (not v.startswith('text/html')
+            and not v.startswith('text/xhtml+xml')):
+            # Can't validate
+            # @@: Should validate CSS too... but using what?
+            return [page]
+        ops = []
+        if v.startswith('text/xhtml+xml'):
+            ops.append('--xml')
+        # @@: Should capture encoding too
+        conf = environ['paste.config']
+        wdg_path = conf.get('wdg_path', 'validate')
+        proc = subprocess.Popen([wdg_path] + ops,
+                                shell=False,
+                                close_fds=True,
+                                stdout=subprocess.PIPE,
+                                stdin=subprocess.PIPE,
+                                stderr=subprocess.STDOUT)
+        stdout = proc.communicate(page)[0]
+        proc.wait()
+        if not stdout:
+            return [page]
+        add_text = '<pre style="background-color: #ffd; color: #600; border: 1px solid #000;">%s</pre>' % cgi.escape(stdout)
+        match = self._end_body_regex.search(page)
+        if match:
+            page = page[:match.start()] + add_text + page[match.end():]
+        else:
+            page += add_text
+        return [page]
+    
+                                
+            
+