Improved docs. Add section Upload File into **Tutorial / Using file…

…s in models**

docs/tutorial/using-files-in-models.md

@@ -52,12 +52,104 @@ uploaded file is a valid image.
         title = Column(String(100), unique=True)
         cover = Column(ImageField(thumbnail_size=(128, 128)))
     ```
-## Uploaded Files Information
+## Upload File
+
+Let's say you defined your model like this
+```python
+class Attachment(Base):
+    __tablename__ = "attachment"
+
+    id = Column(Integer, autoincrement=True, primary_key=True)
+    name = Column(String(50), unique=True)
+    content = Column(FileField)
+```
+and configure your storage like this
+```python
+container = LocalStorageDriver("/tmp/storage").get_container("attachment")
+StorageManager.add_storage("default", container)
+```
+
+### Save file object
+
 Whenever a supported object is assigned to a [FileField][sqlalchemy_file.types.FileField] or [ImageField][sqlalchemy_file.types.ImageField]
 it will be converted to a [File][sqlalchemy_file.file.File] object.
+```python
+with Session(engine) as session:
+    session.add(Attachment(name="attachment1", content=open("./example.txt", "rb")))
+    session.add(Attachment(name="attachment2", content=b"Hello world"))
+    session.add(Attachment(name="attachment3", content="Hello world"))
+    file = File(content="Hello World", filename="hello.txt", content_type="text/plain")
+    session.add(Attachment(name="attachment4", content=file))
+    session.commit()
+```
+The file itself will be uploaded to your configured storage, and only the [File][sqlalchemy_file.file.File]
+information will be stored on the database as JSON.
 
-This is the same object you will get back when reloading the models from database and apart from the file itself which is accessible
-through the `.file` property, it provides additional attributes described into the [File][sqlalchemy_file.file.File] documentation itself.
+### Retrieve file object
+
+This is the same [File][sqlalchemy_file.file.File] object you will get back when reloading the models from database and the file itself is accessible
+through the `.file` property. 
+
+!!! note
+    Check the [File][sqlalchemy_file.file.File] documentation for all default attributes save into the database.
+
+```python
+with Session(engine) as session:
+    attachment = session.execute(
+            select(Attachment).where(Attachment.name == "attachment3")
+        ).scalar_one()
+    assert attachment.content.saved # saved is True for saved file
+    assert attachment.content.file.read() == b"Hello world" # access file content
+    assert attachment.content["filename"] is not None # `unnamed` when no filename are provided
+    assert attachment.content["file_id"] is not None # uuid v4
+    assert attachment.content["upload_storage"] == "default"
+    assert attachment.content["content_type"] is not None
+    assert attachment.content["uploaded_at"] is not None
+```
+
+### Save additional information
+
+It's important to note that [File][sqlalchemy_file.file.File] object inherit from python `dict`.
+Therefore, you can add additional information to your file object like a dict object. Just make sure to not use
+the default attributes used by [File][sqlalchemy_file.file.File] object internally.
+
+!!! Example
+    ```python
+    content = File(open("./example.txt", "rb"),custom_key1="custom_value1", custom_key2="custom_value2") 
+    content["custom_key3"] = "custom_value3"
+    attachment = Attachment(name="Dummy", content=content)
+
+    session.add(attachment)
+    session.commit()
+    session.refresh(attachment)
+
+    assert attachment.custom_key1 == "custom_value1" 
+    assert attachment.custom_key2 == "custom_value2"
+    assert attachment["custom_key3"] == "custom_value3"
+    ```
+
+!!! important
+    [File][sqlalchemy_file.file.File] provides also attribute style access. 
+    You can access your keys as attributes.
+
+### Metadata
+
+*SQLAlchemy-file* store the uploaded file with some metadata. Only `filename` and `content_type` are sent by default,
+. You can complete with `metadata` key inside your [File][sqlalchemy_file.file.File] object.
+
+!!! Example
+    ```py hl_lines="2"
+    with Session(engine) as session:
+        content = File(DummyFile(), metadata={"key1": "val1", "key2": "val2"})
+        attachment = Attachment(name="Additional metadata", content=content)
+        session.add(attachment)
+        session.commit()
+        attachment = session.execute(
+            select(Attachment).where(Attachment.name == "Additional metadata")
+        ).scalar_one()
+        assert attachment.content.file.object.meta_data["key1"] == "val1"
+        assert attachment.content.file.object.meta_data["key2"] == "val2"
+    ```
 
 ## Uploading on a Specific Storage
 
@@ -119,7 +211,7 @@ Validators can add additional properties to the file object. For example
 the file object.
 
 **SQLAlchemy-file** has built-in validators to get started, but you can create your own validator
-by extending [ValidationError][sqlalchemy_file.exceptions.ValidationError] base class.
+by extending [Validator][sqlalchemy_file.validators.Validator] base class.
 
 Built-in validators:
 

docs_src/tutorial/using-files-in-models/008_file_information.py

@@ -0,0 +1,52 @@
+import os
+
+from libcloud.storage.drivers.local import LocalStorageDriver
+from sqlalchemy import Column, Integer, String, create_engine, select
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import Session
+from sqlalchemy_file import File, FileField
+from sqlalchemy_file.storage import StorageManager
+
+Base = declarative_base()
+
+
+# Define your model
+class Attachment(Base):
+    __tablename__ = "attachment"
+
+    id = Column(Integer, autoincrement=True, primary_key=True)
+    name = Column(String(50), unique=True)
+    content = Column(FileField)
+
+
+# Configure Storage
+os.makedirs("/tmp/storage/attachment", 0o777, exist_ok=True)
+container = LocalStorageDriver("/tmp/storage").get_container("attachment")
+StorageManager.add_storage("default", container)
+
+# Save your model
+engine = create_engine(
+    "sqlite:///example.db", connect_args={"check_same_thread": False}
+)
+Base.metadata.create_all(engine)
+
+with Session(engine) as session:
+    session.add(Attachment(name="attachment1", content=open("./example.txt", "rb")))
+    session.add(Attachment(name="attachment2", content=b"Hello world"))
+    session.add(Attachment(name="attachment3", content="Hello world"))
+    file = File(content="Hello World", filename="hello.txt", content_type="text/plain")
+    session.add(Attachment(name="attachment4", content=file))
+    session.commit()
+
+    attachment = session.execute(
+        select(Attachment).where(Attachment.name == "attachment3")
+    ).scalar_one()
+    assert attachment.content.saved  # saved is True for saved file
+    assert attachment.content.file.read() == b"Hello world"  # access file content
+    assert (
+        attachment.content["filename"] is not None
+    )  # `unnamed` when no filename are provided
+    assert attachment.content["file_id"] is not None  # uuid v4
+    assert attachment.content["upload_storage"] == "default"
+    assert attachment.content["content_type"] is not None
+    assert attachment.content["uploaded_at"] is not None

sqlalchemy_file/file.py

@@ -43,8 +43,9 @@ def __init__(
         content: Any,
         filename: Optional[str] = None,
         content_type: Optional[str] = None,
+        **kwargs: Dict[str, Any],
     ) -> None:
-        super().__init__()
+        super().__init__(**kwargs)
         if isinstance(content, dict):
             object.__setattr__(self, "original_content", None)
             object.__setattr__(self, "saved", True)
@@ -83,10 +84,12 @@ def apply_processors(
 
     def save_to_storage(self, upload_storage: Optional[str] = None) -> None:
         """Save current file into provided `upload_storage`"""
+        metadata = self.get("metadata", {})
+        metadata.update({"filename": self.filename, "content_type": self.content_type})
         stored_file = self.store_content(
             self.original_content,
             upload_storage,
-            metadata={"filename": self.filename, "content_type": self.content_type},
+            metadata=metadata,
         )
         self["file_id"] = stored_file.name
         self["upload_storage"] = upload_storage

sqlalchemy_file/processors.py

@@ -114,15 +114,19 @@ def process(self, file: "File", upload_storage: Optional[str] = None) -> None:
             f"image/{self.thumbnail_format}".lower(),
         )
         ext = mimetypes.guess_extension(content_type)
-        stored_file = file.store_content(
-            output,
-            upload_storage,
-            metadata={
+        metadata = file.get("metadata", {})
+        metadata.update(
+            {
                 "filename": file["filename"] + f".thumbnail{width}x{height}{ext}",
                 "content_type": content_type,
                 "width": width,
                 "height": height,
-            },
+            }
+        )
+        stored_file = file.store_content(
+            output,
+            upload_storage,
+            metadata=metadata,
         )
         file.update(
             {

tests/test_result_value.py

@@ -68,6 +68,34 @@ def test_single_column_is_dictlike(self) -> None:
             assert attachment.content.dummy_attr == "Dummy data"
             assert "del_attr" not in attachment.content
 
+    def test_file_custom_attributes(self) -> None:
+        with Session(engine) as session:
+            content = File(
+                DummyFile(), custom_key1="custom_value1", custom_key2="custom_value2"
+            )
+            attachment = Attachment(name="Custom attributes", content=content)
+            session.add(attachment)
+            session.commit()
+            attachment = session.execute(
+                select(Attachment).where(Attachment.name == "Custom attributes")
+            ).scalar_one()
+            assert attachment.content["custom_key1"] == "custom_value1"
+            assert attachment.content["custom_key2"] == "custom_value2"
+            assert attachment.content.custom_key1 == "custom_value1"
+            assert attachment.content.custom_key2 == "custom_value2"
+
+    def test_file_additional_metadata(self) -> None:
+        with Session(engine) as session:
+            content = File(DummyFile(), metadata={"key1": "val1", "key2": "val2"})
+            attachment = Attachment(name="Additional metadata", content=content)
+            session.add(attachment)
+            session.commit()
+            attachment = session.execute(
+                select(Attachment).where(Attachment.name == "Additional metadata")
+            ).scalar_one()
+            assert attachment.content.file.object.meta_data["key1"] == "val1"
+            assert attachment.content.file.object.meta_data["key2"] == "val2"
+
     def test_multiple_column_is_list_of_dictlike(self) -> None:
         with Session(engine) as session:
             attachment = Attachment(