bug 730707: Send doc metadata to kumascript

* Kumascript now accepts env vars as headers with base64/utf8/JSON
  encoded data structures

* Assemble some env vars from document metadata to send in the request
  to kumascript

apps/wiki/tests/test_views.py

@@ -1,6 +1,7 @@
 import logging
 import json
 import base64
+import time
 
 from django.conf import settings
 from django.contrib.sites.models import Site
@@ -229,6 +230,7 @@ def setUp(self):
         super(KumascriptIntegrationTests, self).setUp()
 
         self.d, self.r = doc_rev()
+        self.d.tags.set('foo', 'bar', 'baz')
         self.url = reverse('wiki.document', 
                            args=['%s/%s' % (self.d.locale, self.d.slug)],
                            locale=settings.WIKI_DEFAULT_LANGUAGE)
@@ -459,6 +461,41 @@ def my_requests_get(url, headers=None, timeout=None):
         for error in expected_errors['logs']:
             ok_(error['message'] in response.content)
 
+    @mock.patch('requests.get')
+    def test_env_vars(self, mock_requests_get):
+        """Kumascript reports errors in HTTP headers, Kuma should display them"""
+
+        # Now, trap the request from the view.
+        trap = {}
+        def my_requests_get(url, headers=None, timeout=None):
+            trap['headers'] = headers
+            return FakeResponse(
+                status_code=200,
+                body='HELLO WORLD',
+                headers={}
+            )
+        mock_requests_get.side_effect = my_requests_get
+
+        # Ensure kumascript is enabled
+        constance.config.KUMASCRIPT_TIMEOUT = 1.0
+        constance.config.KUMASCRIPT_MAX_AGE = 600
+
+        # Fire off the request, and capture the env vars that would have been
+        # sent to kumascript
+        response = self.client.get(self.url)
+        pfx = 'x-kumascript-env-'
+        vars = dict(
+            (k[len(pfx):], json.loads(base64.b64decode(v)))
+            for k,v in trap['headers'].items()
+            if k.startswith(pfx))
+
+        # Ensure the env vars intended for kumascript match expected values.
+        for n in ('title', 'slug', 'locale'):
+            eq_(getattr(self.d, n), vars[n])
+        eq_(self.d.get_absolute_url(), vars['path'])
+        eq_(time.mktime(self.d.modified.timetuple()), vars['modified'])
+        eq_(sorted([u'foo', u'bar', u'baz']), sorted(vars['tags']))
+
 
 class DocumentEditingTests(TestCaseBase):
     """Tests for the document-editing view"""

apps/wiki/views.py

@@ -1,4 +1,5 @@
 from datetime import datetime
+import time
 import json
 from collections import defaultdict
 import base64
@@ -241,7 +242,7 @@ def set_common_headers(r):
         #   * The request *has* asked for macro evaluation
         #     (eg. ?raw&macros)
         resp_body, resp_errors = _perform_kumascript_request(
-                request, response_headers, document_locale, document_slug)
+                request, response_headers, doc, document_locale, document_slug)
         if resp_body:
             doc_html = resp_body
         if resp_errors:
@@ -314,8 +315,8 @@ def _invalidate_kumascript_cache(document):
                                                    document.locale))
 
 
-def _perform_kumascript_request(request, response_headers, document_locale,
-                                document_slug):
+def _perform_kumascript_request(request, response_headers, document,
+                                document_locale, document_slug):
     """Perform a kumascript GET request for a document locale and slug.
 
     This is broken out into its own utility function, both to make the view
@@ -359,6 +360,26 @@ def _perform_kumascript_request(request, response_headers, document_locale,
             'Cache-Control': cache_control
         }
 
+        # Assemble some KumaScript env vars
+        # TODO: See dekiscript vars for future inspiration
+        # http://developer.mindtouch.com/en/docs/DekiScript/Reference/Wiki_Functions_and_Variables
+        path = document.get_absolute_url()
+        env_vars = dict(
+            path=path,
+            url=request.build_absolute_uri(path),
+            id=document.pk,
+            locale=document.locale,
+            title=document.title,
+            slug=document.slug,
+            tags=[x.name for x in document.tags.all()],
+            modified=time.mktime(document.modified.timetuple()),
+        )
+        # Encode the vars as kumascript headers, as base64 JSON-encoded values.
+        headers.update(dict(
+            ('x-kumascript-env-%s' % k,
+             base64.b64encode(json.dumps(v)))
+            for k, v in env_vars.items()))
+
         # Set up for conditional GET, if we have the details cached.
         c_meta = cache.get_many([ck_etag, ck_modified])
         if ck_etag in c_meta: