Migrate from Singleton client class to using parameter in Resource methods

src/metabase/metabase.py

@@ -1,21 +1,9 @@
-from weakref import WeakValueDictionary
-
 import requests
 
 from metabase.exceptions import AuthenticationError
 
 
-class Singleton(type):
-    _instances = WeakValueDictionary()
-
-    def __call__(cls, *args, **kw):
-        if cls not in cls._instances:
-            instance = super(Singleton, cls).__call__(*args, **kw)
-            cls._instances[cls] = instance
-        return cls._instances[cls]
-
-
-class Metabase(metaclass=Singleton):
+class Metabase:
     def __init__(self, host: str, user: str, password: str, token: str = None):
         self._host = host
         self.user = user

src/metabase/resource.py

@@ -11,8 +11,9 @@ class Resource:
     ENDPOINT: str
     PRIMARY_KEY: str = "id"
 
-    def __init__(self, **kwargs):
+    def __init__(self, _using: Metabase, **kwargs):
         self._attributes = []
+        self._using = _using
 
         for k, v in kwargs.items():
             self._attributes.append(k)
@@ -31,42 +32,38 @@ def __repr__(self):
             + ")"
         )
 
-    @staticmethod
-    def connection() -> Metabase:
-        return Metabase()
-
 
 class ListResource(Resource):
     @classmethod
-    def list(cls):
+    def list(cls, using: Metabase):
         """List all instances."""
-        response = cls.connection().get(cls.ENDPOINT)
-        records = [cls(**record) for record in response.json()]
+        response = using.get(cls.ENDPOINT)
+        records = [cls(_using=using, **record) for record in response.json()]
         return records
 
 
 class GetResource(Resource):
     @classmethod
-    def get(cls, id: int):
+    def get(cls, id: int, using: Metabase):
         """Get a single instance by ID."""
-        response = cls.connection().get(cls.ENDPOINT + f"/{id}")
+        response = using.get(cls.ENDPOINT + f"/{id}")
 
         if response.status_code == 404 or response.status_code == 204:
             raise NotFoundError(f"{cls.__name__}(id={id}) was not found.")
 
-        return cls(**response.json())
+        return cls(_using=using, **response.json())
 
 
 class CreateResource(Resource):
     @classmethod
-    def create(cls, **kwargs):
+    def create(cls, using: Metabase, **kwargs):
         """Create an instance and save it."""
-        response = cls.connection().post(cls.ENDPOINT, json=kwargs)
+        response = using.post(cls.ENDPOINT, json=kwargs)
 
         if response.status_code not in (200, 202):
             raise HTTPError(response.content.decode())
 
-        return cls(**response.json())
+        return cls(_using=using, **response.json())
 
 
 class UpdateResource(Resource):
@@ -77,7 +74,7 @@ def update(self, **kwargs) -> None:
         ignored from the request.
         """
         params = {k: v for k, v in kwargs.items() if v != MISSING}
-        response = self.connection().put(
+        response = self._using.put(
             self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}", json=params
         )
 
@@ -91,7 +88,7 @@ def update(self, **kwargs) -> None:
 class DeleteResource(Resource):
     def delete(self) -> None:
         """Delete an instance."""
-        response = self.connection().delete(
+        response = self._using.delete(
             self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}"
         )
 

src/metabase/resources/card.py

@@ -2,6 +2,7 @@
 
 from typing import List
 
+from metabase import Metabase
 from metabase.missing import MISSING
 from metabase.resource import CreateResource, GetResource, ListResource, UpdateResource
 
@@ -41,7 +42,7 @@ class Card(ListResource, CreateResource, GetResource, UpdateResource):
     created_at: str
 
     @classmethod
-    def list(cls) -> List[Card]:
+    def list(cls, using: Metabase) -> List[Card]:
         """
         Get all the Cards. Option filter param f can be used to change the set
         of Cards that are returned; default is all, but other options include
@@ -51,18 +52,19 @@ def list(cls) -> List[Card]:
         of each filter option. :card_index:.
         """
         # TODO: add support for endpoint parameters: f, model_id.
-        return super(Card, cls).list()
+        return super(Card, cls).list(using)
 
     @classmethod
-    def get(cls, id: int) -> Card:
+    def get(cls, id: int, using: Metabase) -> Card:
         """
         Get Card with ID.
         """
-        return super(Card, cls).get(id)
+        return super(Card, cls).get(id, using)
 
     @classmethod
     def create(
         cls,
+        using: Metabase,
         name: str,
         dataset_query: dict,  # TODO: DatasetQuery
         visualization_settings: dict,  # TODO: VisualizationSettings
@@ -79,6 +81,7 @@ def create(
         Create a new Card.
         """
         return super(Card, cls).create(
+            using=using,
             name=name,
             dataset_query=dataset_query,
             visualization_settings=visualization_settings,
@@ -129,7 +132,7 @@ def update(
         )
 
     def archive(self):
-        """Archive a Metric."""
+        """Archive a Card."""
         return self.update(
             archived=True, revision_message="Archived by metabase-python."
         )

src/metabase/resources/database.py

@@ -2,6 +2,7 @@
 
 from typing import Any, Dict, List
 
+from metabase import Metabase
 from metabase.missing import MISSING
 from metabase.resource import (
     CreateResource,
@@ -47,18 +48,19 @@ class Database(
     created_at: str
 
     @classmethod
-    def list(cls) -> List[Database]:
-        response = cls.connection().get(cls.ENDPOINT)
-        records = [cls(**db) for db in response.json().get("data", [])]
+    def list(cls, using: Metabase) -> List[Database]:
+        response = using.get(cls.ENDPOINT)
+        records = [cls(_using=using, **db) for db in response.json().get("data", [])]
         return records
 
     @classmethod
-    def get(cls, id: int) -> Database:
-        return super(Database, cls).get(id)
+    def get(cls, id: int, using: Metabase) -> Database:
+        return super(Database, cls).get(id, using=using)
 
     @classmethod
     def create(
         cls,
+        using: Metabase,
         name: str,
         engine: str,
         details: dict,
@@ -75,6 +77,7 @@ def create(
         You must be a superuser to do this.
         """
         return super(Database, cls).create(
+            using=using,
             name=name,
             engine=engine,
             details=details,
@@ -128,51 +131,41 @@ def delete(self) -> None:
 
     def fields(self) -> List[Field]:
         """Get a list of all Fields in Database."""
-        fields = (
-            self.connection()
-            .get(self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/fields")
-            .json()
-        )
-        return [Field(**payload) for payload in fields]
+        fields = self._using.get(
+            self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/fields"
+        ).json()
+        return [Field(_using=self._using, **payload) for payload in fields]
 
     def idfields(self) -> List[Field]:
         """Get a list of all primary key Fields for Database."""
-        fields = (
-            self.connection()
-            .get(self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/idfields")
-            .json()
-        )
-        return [Field(**payload) for payload in fields]
+        fields = self._using.get(
+            self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/idfields"
+        ).json()
+        return [Field(_using=self._using, **payload) for payload in fields]
 
     def schemas(self) -> List[str]:
         """Returns a list of all the schemas found for the database id."""
-        return (
-            self.connection()
-            .get(self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/schemas")
-            .json()
-        )
+        return self._using.get(
+            self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/schemas"
+        ).json()
 
     def tables(self, schema: str) -> List[Table]:
         """Returns a list of Tables for the given Database id and schema."""
-        tables = (
-            self.connection()
-            .get(
-                self.ENDPOINT
-                + f"/{getattr(self, self.PRIMARY_KEY)}"
-                + "/schema"
-                + f"/{schema}"
-            )
-            .json()
-        )
-        return [Table(**payload) for payload in tables]
+        tables = self._using.get(
+            self.ENDPOINT
+            + f"/{getattr(self, self.PRIMARY_KEY)}"
+            + "/schema"
+            + f"/{schema}"
+        ).json()
+        return [Table(_using=self._using, **payload) for payload in tables]
 
     def discard_values(self):
         """
         Discards all saved field values for this Database.
 
         You must be a superuser to do this.
         """
-        return self.connection().post(
+        return self._using.post(
             self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/discard_values"
         )
 
@@ -182,13 +175,13 @@ def rescan_values(self):
 
         You must be a superuser to do this.
         """
-        return self.connection().post(
+        return self._using.post(
             self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/rescan_values"
         )
 
     def sync(self):
         """Update the metadata for this Database. This happens asynchronously."""
-        return self.connection().post(
+        return self._using.post(
             self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/sync"
         )
 
@@ -198,6 +191,6 @@ def sync_schema(self):
 
         You must be a superuser to do this.
         """
-        return self.connection().post(
+        return self._using.post(
             self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/sync_schema"
         )

src/metabase/resources/dataset.py

@@ -4,6 +4,7 @@
 
 import pandas as pd
 
+from metabase import Metabase
 from metabase.resource import CreateResource, Resource
 
 
@@ -37,10 +38,14 @@ class Dataset(CreateResource):
     average_execution_time: int = None
 
     @classmethod
-    def create(cls, database: int, type: str, query: dict, **kwargs) -> Dataset:
+    def create(
+        cls, using: Metabase, database: int, type: str, query: dict, **kwargs
+    ) -> Dataset:
         """Execute a query and retrieve the results in the usual format."""
-        dataset = super(Dataset, cls).create(database=database, type=type, query=query)
-        dataset.data = Data(**dataset.data)
+        dataset = super(Dataset, cls).create(
+            using=using, database=database, type=type, query=query
+        )
+        dataset.data = Data(_using=using, **dataset.data)
         return dataset
 
     def to_pandas(self) -> pd.DataFrame:

src/metabase/resources/field.py

@@ -3,6 +3,7 @@
 from enum import Enum
 from typing import Any, Dict, List, Optional
 
+from metabase import Metabase
 from metabase.missing import MISSING
 from metabase.resource import GetResource, UpdateResource
 
@@ -111,9 +112,9 @@ class VisibilityType(str, Enum):
         sensitive = "sensitive"
 
     @classmethod
-    def get(cls, id: int) -> Field:
+    def get(cls, id: int, using: Metabase) -> Field:
         """Get Field with ID."""
-        return super(Field, cls).get(id)
+        return super(Field, cls).get(id, using=using)
 
     def update(
         self,
@@ -145,11 +146,9 @@ def update(
 
     def related(self) -> Dict[str, Any]:
         """Return related entities."""
-        return (
-            self.connection()
-            .get(self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/related")
-            .json()
-        )
+        return self._using.get(
+            self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/related"
+        ).json()
 
     def discard_values(self):
         """
@@ -159,7 +158,7 @@ def discard_values(self):
 
         You must be a superuser to do this.
         """
-        return self.connection().post(
+        return self._using.post(
             self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/discard_values"
         )
 
@@ -170,6 +169,6 @@ def rescan_values(self):
 
         You must be a superuser to do this.
         """
-        return self.connection().post(
+        return self._using.post(
             self.ENDPOINT + f"/{getattr(self, self.PRIMARY_KEY)}" + "/rescan_values"
         )