Merge pull request #5 from sinisaos/add_get_readable_method

added get_readable method

Author: sinisaos

example/home/tables.py

@@ -1,5 +1,7 @@
+from piccolo.apps.user.tables import BaseUser
+from piccolo.columns import Boolean, ForeignKey, Timestamp, Varchar
+from piccolo.columns.readable import Readable
 from piccolo.table import Table
-from piccolo.columns import Varchar, Boolean
 
 
 class Task(Table):
@@ -9,3 +11,9 @@ class Task(Table):
 
     name = Varchar()
     completed = Boolean(default=False)
+    created_at = Timestamp()
+    task_user = ForeignKey(references=BaseUser)
+
+    @classmethod
+    def get_readable(cls):
+        return Readable(template="%s", columns=[cls.task_user.username])

piccolo_cursor_pagination/pagination.py

@@ -27,11 +27,12 @@ class CursorPagination:
     async def get_cursor_rows(self, table: t.Type[Table], request: Request):
         # headers to adding next_cursor
         headers: t.Dict[str, str] = {}
+        all_columns: t.Any = table.all_columns()
 
         if self.order_by == "id":
             # query where limit is equal to page_size plus
             # one in ASC order
-            query = table.select().order_by(
+            query = table.select(all_columns, table.get_readable()).order_by(
                 table._meta.primary_key, ascending=True
             )
             query = query.limit(self.page_size + 1)
@@ -73,25 +74,12 @@ async def get_cursor_rows(self, table: t.Type[Table], request: Request):
                 # set new value to next_cursor
                 next_cursor = self.encode_cursor(str(rows[-1]["id"]))
                 headers["cursor"] = next_cursor
-                # if the last_row of whole data set is in rows, it means that
-                # there are no more results, then we must use the first item
-                # in the rows to get the correct result of the previous rows
-                last_row = await (
-                    table.select()
-                    .limit(1)
-                    .order_by(table._meta.primary_key, ascending=False)
-                    .first()
-                    .run()
-                )
-                if (
-                    await self.decode_cursor(next_cursor, table)
-                    == last_row["id"]
-                ):
+                if len(rows) <= self.page_size:
                     headers["cursor"] = self.encode_cursor(str(rows[0]["id"]))
         else:
             # query where limit is equal to page_size plus
             # one in DESC order
-            query = table.select().order_by(
+            query = table.select(all_columns, table.get_readable()).order_by(
                 table._meta.primary_key, ascending=False
             )
             query = query.limit(self.page_size + 1)
@@ -139,14 +127,7 @@ async def get_cursor_rows(self, table: t.Type[Table], request: Request):
                 # set new value to next_cursor
                 next_cursor = self.encode_cursor(str(rows[-1]["id"]))
                 headers["cursor"] = next_cursor
-                # if the last_row of whole data set is in rows, it means that
-                # there are no more results, then we must use the first item
-                # in the rows to get the correct result of the previous rows
-                last_row = await (table.select().limit(1).first().run())
-                if (
-                    await self.decode_cursor(next_cursor, table)
-                    == last_row["id"]
-                ):
+                if len(rows) <= self.page_size:
                     headers["cursor"] = self.encode_cursor(str(rows[0]["id"]))
 
         query = query.limit(self.page_size)

tests/test_cursor_pagination_asc.py

@@ -2,7 +2,7 @@
 from unittest import TestCase
 
 from fastapi import FastAPI, Request
-from piccolo.columns import Integer, Varchar
+from piccolo.columns import ForeignKey, Integer, Varchar
 from piccolo.columns.readable import Readable
 from piccolo.table import Table
 from starlette.responses import JSONResponse
@@ -11,13 +11,18 @@
 from piccolo_cursor_pagination.pagination import CursorPagination
 
 
+class Director(Table):
+    name = Varchar(length=100, required=True)
+
+
 class Movie(Table):
     name = Varchar(length=100, required=True)
     rating = Integer()
+    director = ForeignKey(references=Director)
 
     @classmethod
     def get_readable(cls):
-        return Readable(template="%s", columns=[cls.name])
+        return Readable(template="%s", columns=[cls.director.name])
 
 
 app = FastAPI()
@@ -30,22 +35,26 @@ async def movies(
     __previous: t.Optional[str] = None,
 ):
     try:
-        cursor = request.query_params["__cursor"]
-        paginator = CursorPagination(cursor=cursor, page_size=1, order_by="id")
-        rows_result, headers_result = await paginator.get_cursor_rows(
-            Movie, request
-        )
-        rows = await rows_result.run()
-        headers = headers_result
-        response = JSONResponse(
-            {"rows": rows[::-1]},
-            headers={
-                "next_cursor": headers["cursor"],
-            },
-        )
+        previous = request.query_params["__previous"]
+        if previous:
+            paginator = CursorPagination(
+                cursor=__cursor, page_size=2, order_by="id"
+            )
+            rows_result, headers_result = await paginator.get_cursor_rows(
+                Movie, request
+            )
+            rows = await rows_result.run()
+            headers = headers_result
+            response = JSONResponse(
+                {"rows": rows[::-1]},
+                headers={
+                    "next_cursor": headers["cursor"],
+                },
+            )
     except KeyError:
-        cursor = request.query_params["__cursor"]
-        paginator = CursorPagination(cursor=cursor, page_size=1, order_by="id")
+        paginator = CursorPagination(
+            cursor=__cursor, page_size=2, order_by="id"
+        )
         rows_result, headers_result = await paginator.get_cursor_rows(
             Movie, request
         )
@@ -62,29 +71,67 @@ async def movies(
 
 class TestCursorPaginationAsc(TestCase):
     def setUp(self):
+        Director.create_table(if_not_exists=True).run_sync()
         Movie.create_table(if_not_exists=True).run_sync()
 
     def tearDown(self):
+        Director.alter().drop_table().run_sync()
         Movie.alter().drop_table().run_sync()
 
     def test_cursor_pagination_asc(self):
         """
         If cursor is applied
         """
+        Director.insert(
+            Director(name="George Lucas"),
+            Director(name="Ridley Scott"),
+        ).run_sync()
+
         Movie.insert(
-            Movie(name="Star Wars", rating=93),
-            Movie(name="Lord of the Rings", rating=90),
+            Movie(name="Star Wars", rating=93, director=1),
+            Movie(name="Blade Runner", rating=90, director=2),
+            Movie(name="Alien", rating=91, director=2),
         ).run_sync()
 
         client = TestClient(app)
         response = client.get("/movies/", params={"__cursor": ""})
         self.assertTrue(response.status_code, 200)
-        self.assertEqual(response.headers["next_cursor"], "MQ==")
+        self.assertEqual(response.headers["next_cursor"], "Mw==")
+        self.assertEqual(
+            response.json(),
+            {
+                "rows": [
+                    {
+                        "id": 1,
+                        "name": "Star Wars",
+                        "rating": 93,
+                        "director": 1,
+                        "readable": "George Lucas",
+                    },
+                    {
+                        "id": 2,
+                        "name": "Blade Runner",
+                        "rating": 90,
+                        "director": 2,
+                        "readable": "Ridley Scott",
+                    },
+                ]
+            },
+        )
+        response = client.get("/movies/", params={"__cursor": "Mw=="})
+        self.assertTrue(response.status_code, 200)
+        self.assertEqual(response.headers["next_cursor"], "Mw==")
         self.assertEqual(
             response.json(),
             {
                 "rows": [
-                    {"id": 1, "name": "Star Wars", "rating": 93},
+                    {
+                        "id": 3,
+                        "name": "Alien",
+                        "rating": 91,
+                        "director": 2,
+                        "readable": "Ridley Scott",
+                    },
                 ]
             },
         )
@@ -93,22 +140,41 @@ def test_cursor_pagination_asc_previous(self):
         """
         If cursor ad previous is applied
         """
+        Director.insert(
+            Director(name="George Lucas"),
+            Director(name="Ridley Scott"),
+        ).run_sync()
+
         Movie.insert(
-            Movie(name="Star Wars", rating=93),
-            Movie(name="Lord of the Rings", rating=90),
+            Movie(name="Star Wars", rating=93, director=1),
+            Movie(name="Blade Runner", rating=90, director=2),
+            Movie(name="Alien", rating=91, director=2),
         ).run_sync()
 
         client = TestClient(app)
         response = client.get(
-            "/movies/", params={"__cursor": "Mg==", "__previous": "yes"}
+            "/movies/", params={"__cursor": "Mw==", "__previous": "yes"}
         )
         self.assertTrue(response.status_code, 200)
         self.assertEqual(response.headers["next_cursor"], "")
         self.assertEqual(
             response.json(),
             {
                 "rows": [
-                    {"id": 1, "name": "Star Wars", "rating": 93},
+                    {
+                        "id": 1,
+                        "name": "Star Wars",
+                        "rating": 93,
+                        "director": 1,
+                        "readable": "George Lucas",
+                    },
+                    {
+                        "id": 2,
+                        "name": "Blade Runner",
+                        "rating": 90,
+                        "director": 2,
+                        "readable": "Ridley Scott",
+                    },
                 ]
             },
         )
@@ -118,9 +184,15 @@ def test_cursor_pagination_asc_previous_no_more_results(self):
         If cursor is empty and previous is applied there is no
         more results, return empty rows
         """
+        Director.insert(
+            Director(name="George Lucas"),
+            Director(name="Ridley Scott"),
+        ).run_sync()
+
         Movie.insert(
-            Movie(name="Star Wars", rating=93),
-            Movie(name="Lord of the Rings", rating=90),
+            Movie(name="Star Wars", rating=93, director=1),
+            Movie(name="Blade Runner", rating=90, director=2),
+            Movie(name="Alien", rating=91, director=2),
         ).run_sync()
 
         client = TestClient(app)