total mess: some random experiments with images and lqc's dvcs

[redakcja.git] / apps / wiki_img / helpers.py

diff --git a/apps/wiki_img/helpers.py b/apps/wiki_img/helpers.py
new file mode 100644 (file)
index 0000000..f072ef9
--- /dev/null
+++ b/apps/wiki_img/helpers.py
@@ -0,0 +1,131 @@
+from django import http
+from django.utils import simplejson as json
+from django.utils.functional import Promise
+from datetime import datetime
+from functools import wraps
+
+
+class ExtendedEncoder(json.JSONEncoder):
+
+    def default(self, obj):
+        if isinstance(obj, Promise):
+            return unicode(obj)
+
+        if isinstance(obj, datetime):
+            return datetime.ctime(obj) + " " + (datetime.tzname(obj) or 'GMT')
+
+        return json.JSONEncoder.default(self, obj)
+
+
+# shortcut for JSON reponses
+class JSONResponse(http.HttpResponse):
+
+    def __init__(self, data={}, **kwargs):
+        # get rid of mimetype
+        kwargs.pop('mimetype', None)
+
+        data = json.dumps(data, cls=ExtendedEncoder)
+        super(JSONResponse, self).__init__(data, mimetype="application/json", **kwargs)
+
+
+# return errors
+class JSONFormInvalid(JSONResponse):
+    def __init__(self, form):
+        super(JSONFormInvalid, self).__init__(form.errors, status=400)
+
+
+class JSONServerError(JSONResponse):
+    def __init__(self, *args, **kwargs):
+        kwargs['status'] = 500
+        super(JSONServerError, self).__init__(*args, **kwargs)
+
+
+def ajax_login_required(view):
+    @wraps(view)
+    def authenticated_view(request, *args, **kwargs):
+        if not request.user.is_authenticated():
+            return http.HttpResponse("Login required.", status=401, mimetype="text/plain")
+        return view(request, *args, **kwargs)
+    return authenticated_view
+
+
+def ajax_require_permission(permission):
+    def decorator(view):
+        @wraps(view)
+        def authorized_view(request, *args, **kwargs):
+            if not request.user.has_perm(permission):
+                return http.HttpResponse("Access Forbidden.", status=403, mimetype="text/plain")
+            return view(request, *args, **kwargs)
+        return authorized_view
+    return decorator
+
+import collections
+
+def recursive_groupby(iterable):
+    """
+#    >>> recursive_groupby([1,2,3,4,5])
+#    [1, 2, 3, 4, 5]
+
+    >>> recursive_groupby([[1]])
+    [1]
+
+    >>> recursive_groupby([('a', 1),('a', 2), 3, ('b', 4), 5])
+    ['a', [1, 2], 3, 'b', [4], 5]
+
+    >>> recursive_groupby([('a', 'x', 1),('a', 'x', 2), ('a', 'x', 3)])
+    ['a', ['x', [1, 2, 3]]]
+
+    """
+
+    def _generator(iterator):
+        group = None
+        grouper = None
+
+        for item in iterator:
+            if not isinstance(item, collections.Sequence):
+                if grouper is not None:
+                    yield grouper
+                    if len(group):
+                        yield recursive_groupby(group)
+                    group = None
+                    grouper = None
+                yield item
+                continue
+            elif len(item) == 1:
+                if grouper is not None:
+                    yield grouper
+                    if len(group):
+                        yield recursive_groupby(group)
+                    group = None
+                    grouper = None
+                yield item[0]
+                continue
+            elif not len(item):
+                continue
+
+            if grouper is None:
+                group = [item[1:]]
+                grouper = item[0]
+                continue
+
+            if grouper != item[0]:
+                if grouper is not None:
+                    yield grouper
+                    if len(group):
+                        yield recursive_groupby(group)
+                    group = None
+                    grouper = None
+                group = [item[1:]]
+                grouper = item[0]
+                continue
+
+            group.append(item[1:])
+
+        if grouper is not None:
+            yield grouper
+            if len(group):
+                yield recursive_groupby(group)
+            group = None
+            grouper = None
+
+    return list(_generator(iterable))