Refactor Paginated to be used similarly to how Connection is used

docs/guide/pagination.md

@@ -28,7 +28,7 @@ type Fruit {
 
 input OffsetPaginationInput {
   offset: Int! = 0
-  limit: Int! = -1
+  limit: Int = null
 }
 
 type Query {
@@ -107,7 +107,7 @@ class Fruit:
 
 @strawberry.type
 class Query:
-    fruits: OffsetPaginated[Fruit] = strawberry_django.field()
+    fruits: OffsetPaginated[Fruit] = strawberry_django.offset_paginated()
 ```
 
 Would produce the following schema:
@@ -118,7 +118,7 @@ type Fruit {
 }
 
 type PaginationInfo {
-  limit: Int!
+  limit: Int = null
   offset: Int!
 }
 
@@ -130,7 +130,7 @@ type FruitOffsetPaginated {
 
 input OffsetPaginationInput {
   offset: Int! = 0
-  limit: Int! = -1
+  limit: Int = null
 }
 
 type Query {
@@ -159,6 +159,77 @@ query {
 > OffsetPaginated follow the same rules for the default pagination limit, and can be configured
 > in the same way as explained above.
 
+### Customizing queryset resolver
+
+It is possible to define a custom resolver for the queryset to either provide a custom
+queryset for it, or even to receive extra arguments alongside the pagination arguments.
+
+Suppose we want to pre-filter a queryset of fruits for only available ones,
+while also adding [ordering](./ordering.md) to it. This can be achieved like:
+
+```python title="types.py"
+
+@strawberry_django.type(models.Fruit)
+class Fruit:
+    name: auto
+    price: auto
+
+
+@strawberry_django.order(models.Fruit)
+class FruitOrder:
+    name: auto
+    price: auto
+
+
+@strawberry.type
+class Query:
+    @straberry.offset_paginated(OffsetPaginated[Fruit], order=order)
+    def fruits(self, only_available: bool = True) -> QuerySet[Fruit]:
+        queryset = models.Fruit.objects.all()
+        if only_available:
+            queryset = queryset.filter(available=True)
+
+        return queryset
+```
+
+This would produce the following schema:
+
+```graphql title="schema.graphql"
+type Fruit {
+  name: String!
+  price: Decimal!
+}
+
+type FruitOrder {
+  name: Ordering
+  price: Ordering
+}
+
+type PaginationInfo {
+  limit: Int!
+  offset: Int!
+}
+
+type FruitOffsetPaginated {
+  pageInfo: PaginationInfo!
+  totalCount: Int!
+  results: [Fruit]!
+}
+
+input OffsetPaginationInput {
+  offset: Int! = 0
+  limit: Int = null
+}
+
+type Query {
+  fruits(
+    onlyAvailable: Boolean! = true
+    pagination: OffsetPaginationInput
+    order: FruitOrder
+  ): [FruitOffsetPaginated!]!
+}
+```
+
 ### Customizing the pagination
 
 Like other generics, `OffsetPaginated` can be customized to modify its behavior or to
@@ -195,7 +266,7 @@ class FruitOffsetPaginated(OffsetPaginated[Fruit]):
 
 @strawberry.type
 class Query:
-    fruits: FruitOffsetPaginated = strawberry_django.field()
+    fruits: FruitOffsetPaginated = strawberry_django.offset_paginated()
 ```
 
 Would produce the following schema:
@@ -206,7 +277,7 @@ type Fruit {
 }
 
 type PaginationInfo {
-  limit: Int!
+  limit: Int = null
   offset: Int!
 }
 
@@ -220,7 +291,7 @@ type FruitOffsetPaginated {
 
 input OffsetPaginationInput {
   offset: Int! = 0
-  limit: Int! = -1
+  limit: Int = null
 }
 
 type Query {

strawberry_django/__init__.py

@@ -1,5 +1,5 @@
 from . import auth, filters, mutations, ordering, pagination, relay
-from .fields.field import connection, field, node
+from .fields.field import connection, field, node, offset_paginated
 from .fields.filter_order import filter_field, order_field
 from .fields.filter_types import (
     BaseFilterLookup,
@@ -60,6 +60,7 @@
     "mutation",
     "mutations",
     "node",
+    "offset_paginated",
     "order",
     "order_field",
     "ordering",