From 25adb9b9238d0fc168a292cace7684de9112be64 Mon Sep 17 00:00:00 2001
From: changeling <cklarson@gmail.com>
Date: Wed, 15 May 2019 12:54:36 -0500
Subject: [PATCH] Created Adding counts to DjangoFilterConnectionField
 (markdown)

---
 ...g-counts-to-DjangoFilterConnectionField.md | 85 +++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100644 Adding-counts-to-DjangoFilterConnectionField.md

diff --git a/Adding-counts-to-DjangoFilterConnectionField.md b/Adding-counts-to-DjangoFilterConnectionField.md
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+`DjangoFilterConnectionField()` can be tricky to work with in cases where you wish to extend your schema. Fortunately, the solution is simple.
+
+The trick here is to subclass `Connection` and declare a `connection_class` on your node type. In your Query declarations, `DjangoFilterConnectionField` will use that declared `connection_class` class seamlessly wherever it's defined.
+
+You can now easily implement counts (or really anything) on your extended `Connection` class and use them in your queries, while retaining the built-in filtering that comes with `DjangoFilterConnectionField`:
+
+```
+from graphene import ObjectType, Connection, Node, Int
+from graphene_django import DjangoObjectType
+from graphene_django.filter import DjangoFilterConnectionField
+from ..models import Place
+
+
+class ExtendedConnection(Connection):
+    class Meta:
+        abstract = True
+
+    total_count = Int()
+    edge_count = Int()
+
+    def resolve_total_count(root, info, **kwargs):
+        return root.length
+    def resolve_edge_count(root, info, **kwargs):
+        return len(root.edges)
+
+
+class PlaceType(DjangoObjectType):
+    class Meta:
+        model = Place
+        filter_fields = {
+            'id':  ['exact', 'icontains'],
+            'name': ['exact', 'icontains', 'istartswith', 'iendswith'],
+        }
+        interfaces = (Node, )
+        connection_class = ExtendedConnection
+
+
+class Query(ObjectType):
+    places = DjangoFilterConnectionField(PlaceType)
+```
+
+This allows, on this example `schema`, querying:
+```
+{
+  places(first: 2, name_Icontains: "Dallas", after: "YXJyYXljb25uZWN0aW9uOjE1") {
+    totalCount
+    edgeCount
+    edges {
+      cursor
+      node {
+        id
+        name
+      }
+    }
+  }
+}
+```
+
+Which returns:
+```
+{
+  "data": {
+    "places": {
+      "totalCount": 23,
+      "edgeCount": 2,
+      "edges": [
+        {
+          "cursor": "YXJyYXljb25uZWN0aW9uOjE2",
+          "node": {
+            "id": "UGxhY2VUeXBlOjUxOA==",
+            "name": "Dallas, Dallas, Texas, United States"
+          }
+        },
+        {
+          "cursor": "YXJyYXljb25uZWN0aW9uOjE3",
+          "node": {
+            "id": "UGxhY2VUeXBlOjU0Nw==",
+            "name": "Election Precinct 4 Valley Creek, Dallas, Alabama, United States"
+          }
+        }
+      ]
+    }
+  }
+}
+```
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