Merge b474c275b7 into db7d15d5d1

djangorestframework/mixins.py

@@ -6,7 +6,9 @@ classes that can be added to a `View`.
 from django.contrib.auth.models import AnonymousUser
 from django.core.paginator import Paginator
 from django.db.models.fields.related import ForeignKey
+from django.db.models import Q
 from django.http import HttpResponse
+from django.utils.safestring import mark_safe
 from urlobject import URLObject
 
 from djangorestframework import status
@@ -31,7 +33,8 @@ __all__ = (
     'UpdateModelMixin',
     'DeleteModelMixin',
     'ListModelMixin',
-    'PaginatorMixin'
+    'PaginatorMixin',
+    'FilterMixin'
 )
 
 
@@ -461,12 +464,13 @@ class ModelMixin(object):
 
     queryset = None
 
-    def get_query_kwargs(self, *args, **kwargs):
+    def get_query_args(self, *args, **kwargs):
         """
         Return a dict of kwargs that will be used to build the
         model instance retrieval or to filter querysets.
         """
 
+        args = list(args)
         kwargs = dict(kwargs)
 
         # If the URLconf includes a .(?P<format>\w+) pattern to match against
@@ -475,7 +479,7 @@ class ModelMixin(object):
         if BaseRenderer._FORMAT_QUERY_PARAM in kwargs:
             del kwargs[BaseRenderer._FORMAT_QUERY_PARAM]
 
-        return kwargs
+        return [], kwargs
 
     def get_instance_data(self, model, content, **kwargs):
         """
@@ -504,11 +508,11 @@ class ModelMixin(object):
 
         return all_kw_args
 
-    def get_instance(self, **kwargs):
+    def get_instance(self, *args, **kwargs):
         """
         Get a model instance for read/update/delete requests.
         """
-        return self.get_queryset().get(**kwargs)
+        return self.get_queryset().get(*args, **kwargs)
 
     def get_queryset(self):
         """
@@ -530,10 +534,10 @@ class ReadModelMixin(ModelMixin):
     """
     def get(self, request, *args, **kwargs):
         model = self.resource.model
-        query_kwargs = self.get_query_kwargs(request, *args, **kwargs)
+        query_args, query_kwargs = self.get_query_args(request, **kwargs)
 
         try:
-            self.model_instance = self.get_instance(**query_kwargs)
+            self.model_instance = self.get_instance(*query_args, **query_kwargs)
         except model.DoesNotExist:
             raise ErrorResponse(status.HTTP_404_NOT_FOUND)
 
@@ -586,12 +590,12 @@ class UpdateModelMixin(ModelMixin):
     """
     def put(self, request, *args, **kwargs):
         model = self.resource.model
-        query_kwargs = self.get_query_kwargs(request, *args, **kwargs)
+        query_args, query_kwargs = self.get_query_args(request, **kwargs)
 
         # TODO: update on the url of a non-existing resource url doesn't work
         # correctly at the moment - will end up with a new url
         try:
-            self.model_instance = self.get_instance(**query_kwargs)
+            self.model_instance = self.get_instance(*query_args, **query_kwargs)
 
             for (key, val) in self.CONTENT.items():
                 setattr(self.model_instance, key, val)
@@ -607,10 +611,10 @@ class DeleteModelMixin(ModelMixin):
     """
     def delete(self, request, *args, **kwargs):
         model = self.resource.model
-        query_kwargs = self.get_query_kwargs(request, *args, **kwargs)
+        query_args, query_kwargs = self.get_query_args(request, **kwargs)
 
         try:
-            instance = self.get_instance(**query_kwargs)
+            instance = self.get_instance(*query_args, **query_kwargs)
         except model.DoesNotExist:
             raise ErrorResponse(status.HTTP_404_NOT_FOUND, None, {})
 
@@ -626,9 +630,9 @@ class ListModelMixin(ModelMixin):
     def get(self, request, *args, **kwargs):
         queryset = self.get_queryset()
         ordering = self.get_ordering()
-        query_kwargs = self.get_query_kwargs(request, *args, **kwargs)
+        query_args, query_kwargs = self.get_query_args(request, **kwargs)
 
-        queryset = queryset.filter(**query_kwargs)
+        queryset = queryset.filter(*query_args, **query_kwargs)
         if ordering:
             queryset = queryset.order_by(*ordering)
 
@@ -734,3 +738,184 @@ class PaginatorMixin(object):
         serialized_page_info['results'] = serialized_object_list
 
         return serialized_page_info
+
+
+class FilterMixin(object):
+
+    """
+    `Mixin` class that allows to filter results based on the value of their fields,
+    by passing Django's `QuerySet` arguments in GET requests.
+    """
+
+    filter_fields = {}
+    """
+    Dictionary listing the names of the fields (dictionary's keys) that can be fetched,
+    according to a selection of Django's `QuerySet` field lookups
+    (see https://docs.djangoproject.com/en/1.4/ref/models/querysets/#field-lookups).
+
+    Querystring example: ?username__istartswith=joe&email__endswith=mydomain.com
+
+    Field lookups' declaration:
+
+    filter_fields = {
+        'username': True, # All field lookups are allowed.
+        'email': {'exclude': ('regex', 'iregex',)}, # All field lookups are allowed but 'regex' and 'iregex'.
+        'first_name': {'fields': ('exact', 'iexact',)}, # Only 'exact' and 'iexact' field lookups are allowed.
+    }
+    """
+
+    filter_required = True
+    """
+    Will return an empty `QuerySet` if set to True and filtering wasn't not properly triggered (via the GET request).
+    """
+
+    def __init__(self,  *args, **kwargs):
+
+        self._filter_lookups = {
+            'exact':       self._filter_lookup_value_orig,
+            'iexact':      self._filter_lookup_value_orig,
+            'contains':    self._filter_lookup_value_orig,
+            'icontains':   self._filter_lookup_value_orig,
+            'in':          self._filter_lookup_value_list,
+            'gt':          self._filter_lookup_value_field,
+            'gte':         self._filter_lookup_value_field,
+            'lt':          self._filter_lookup_value_field,
+            'lte':         self._filter_lookup_value_field,
+            'startswith':  self._filter_lookup_value_orig,
+            'istartswith': self._filter_lookup_value_orig,
+            'endswith':    self._filter_lookup_value_orig,
+            'iendswith':   self._filter_lookup_value_orig,
+            'range':       self._filter_lookup_value_list,
+            'year':        self._filter_lookup_value_int,
+            'month':       self._filter_lookup_value_int,
+            'day':         self._filter_lookup_value_int,
+            'week_day':    self._filter_lookup_value_int,
+            'isnull':      lambda field, value: value.lower() == 'true',
+            'search':      self._filter_lookup_value_orig,
+            'regex':       self._filter_lookup_value_re,
+            'iregex':      self._filter_lookup_value_re
+            }
+
+        for k, v in self.filter_fields.items():
+
+            if v == True: self.filter_fields[k] = set(self._filter_lookups.keys())
+
+            elif isinstance(v, dict):
+
+                fields = set()
+
+                if 'fields' in v: fields = set(v['fields'])
+                else: fields = set(self._filter_lookups.keys())
+
+                if 'exclude' in v: fields = fields - set(v['exclude'])
+
+                self.filter_fields[k] = fields
+
+        super(FilterMixin, self).__init__(*args, **kwargs)
+
+    def _filter_lookup_value_field(self, field, value):
+
+        return self.resource.model._meta.get_field(field).to_python(value)
+
+    def _filter_lookup_value_orig(self, field, value): return value
+
+    def _filter_lookup_value_int(self, field, value): return int(value)
+
+    def _filter_lookup_value_re(self, field, value): return r'%s' % value
+
+    def _filter_lookup_value_list(self, field, value):
+
+        split = value.split(',')
+        try: return map(lambda x: self._filter_lookup_value_field(field, x), split)
+        except TypeError: return split
+
+    def get_description(self, html):
+
+        """
+        Appends filter's documentation to the `Resource`'s description.
+        """ 
+
+        desc = super(FilterMixin, self).get_description(html)
+
+        if not len(self.filter_fields): return desc
+
+        filter_desc_req = u' (required)' if self.filter_required else u''
+
+        # Sort fields and lookup suffixes in alphabetical order for readability.
+        # Not using OrderedDict for Python <= 2.6 compatibility.
+        filter_fields_ordered_keys = list(self.filter_fields.keys())
+        filter_fields_ordered_keys.sort()
+        filter_fields_ordered_lookups = dict(map(lambda k: (k, list(self.filter_fields[k]),), filter_fields_ordered_keys))
+        map(lambda v: v.sort(), filter_fields_ordered_lookups.values())
+        filter_desc_example = u'%s__%s' % (filter_fields_ordered_keys[0], filter_fields_ordered_lookups[filter_fields_ordered_keys[0]][0])
+
+        if html:
+
+            filter_desc_fields_html = u''.join(map(lambda k: \
+                u'<li><code><strong>%s</strong></code> <em>+</em> <code>__</code> <em>+</em> <code>%s</code>.</li>' \
+                % (k, u'</code><em>,</em> <code>'.join(filter_fields_ordered_lookups[k])), filter_fields_ordered_keys))
+
+            filter_desc = u"""<h2 id="filter_options_title">Filter options%s</h2>
+<div id="filter_options">
+<p>The following fields can be used to filter results in GET requests,
+they should be extended by <a href="https://docs.djangoproject.com/en/1.4/ref/models/querysets/#field-lookups">lookup suffixes</a>
+with a double underscore (e.g. <a href="./?%s="><code>?%s=</code></a>)
+except for the <code>exact</code> suffix which is the default:</p>
+<ul>%s</ul>
+<p>The default statement between multiple fields is <code>AND</code>, if the <code>or__</code> prefix is used then the statement will be <code>OR</code> (e.g. <a href="./?or__%s="><code>?or__%s=</code></a>)
+.</p>
+</div>
+"""  % (filter_desc_req, filter_desc_example, filter_desc_example,
+        filter_desc_fields_html, filter_desc_example, filter_desc_example,)
+
+            return mark_safe(u'%s\n%s' % (desc, filter_desc))
+
+        else:
+
+            filter_desc_fields_txt = u'\n'.join(map(lambda k: u'* %s: %s.' \
+                    % (k, u', '.join(filter_fields_ordered_lookups[k])), filter_fields_ordered_keys))
+
+            return u"""%s\n\nFilter options%s:\n\n%s""" % (desc, filter_desc_req, filter_desc_fields_txt)
+
+    def get_query_args(self, *args, **kwargs):
+
+        """
+        Return the `QuerySet`'s args and kwargs according to the GET request's arguments.
+        """
+
+        args, kwargs = super(FilterMixin, self).get_query_args(self, *args, **kwargs)
+        self._filter_triggered = False
+        q = None
+
+        for k, v in self.request.GET.items():
+
+            if k.startswith('or__'):
+                q_or = True
+                k = k[4:]
+            else: q_or = False
+
+            field = k.split('__')
+            if len(field) == 2: lookup = field[1]
+            else: lookup = 'exact'
+            field = field[0]
+
+            if v and field in self.filter_fields and lookup in self.filter_fields[field]:
+
+                v = self._filter_lookups[lookup](field, v)
+                if not q_or: kwargs['%s__%s' % (field, lookup)] = v
+                else:
+                    q_this = Q(**{'%s__%s' % (field, lookup): v})
+                    if q: q = q | q_this
+                    else: q = q_this
+                self._filter_triggered = True
+
+        if q: args.append(q)
+
+        return args, kwargs
+
+    def get(self, *args, **kwargs):
+
+        queryset = super(FilterMixin, self).get(*args, **kwargs)
+        if self.filter_required and not self._filter_triggered:
+            return self.resource.model.objects.none()
+        return queryset