initial file upload support (#31)

* initial file upload support

examples/app.py

@@ -18,6 +18,7 @@
     CheckboxLiveView,
     PresenceLiveView,
     MapLiveView,
+    FileUploadDemoLiveView,
 )
 
 app = PyView()
@@ -147,6 +148,15 @@ def content_wrapper(_context, content: Markup) -> Markup:
         forth between the liveview and the JS library.
         """,
     ),
+    (
+        "/file_upload",
+        FileUploadDemoLiveView,
+        "File Upload",
+        "file_upload",
+        """
+        File upload example, with previews and progress bars.
+        """,
+    ),
 ]
 
 for path, view, _, _, _ in routes:

examples/justfile

@@ -0,0 +1,2 @@
+start:
+  PYVIEW_SECRET=`openssl rand -base64 16` poetry run uvicorn examples.app:app --reload

examples/pyproject.toml

@@ -10,6 +10,7 @@ package-mode = false
 python = "^3.9.16"
 pyview-web = {path = "..", develop = true}
 aiohttp = "^3.9.4"
+pillow = "^10.4.0"
 
 
 [build-system]

examples/views/__init__.py

@@ -11,6 +11,7 @@
 from .checkboxes import CheckboxLiveView
 from .presence import PresenceLiveView
 from .maps import MapLiveView
+from .file_upload import FileUploadDemoLiveView
 
 __all__ = [
     "CountLiveView",
@@ -27,4 +28,5 @@
     "CheckboxLiveView",
     "PresenceLiveView",
     "MapLiveView",
+    "FileUploadDemoLiveView",
 ]

examples/views/file_upload/file_repository.py

@@ -0,0 +1,48 @@
+import collections
+import base64
+from PIL import Image
+from io import BytesIO
+
+
+class FileEntry:
+    file_name: str
+    file_bytes: bytes
+    content_type: str
+
+    def __init__(self, file_name, file_path, content_type):
+        self.file_name = file_name
+        self.content_type = content_type
+        self.file_bytes = create_thumbnail_bytes(file_path)
+
+    @property
+    def base64(self):
+        return base64.b64encode(self.file_bytes).decode("utf-8")
+
+    @property
+    def inline_image(self):
+        return f"data:{self.content_type};base64,{self.base64}"
+
+
+class FileRepository:
+    """
+    A simple repository to store file entries thumbnails as base64 strings for demo purposes.
+    """
+    def __init__(self):
+        self.all_files = collections.deque(maxlen=10)
+
+    def add_file(self, file_name, file_path, content_type):
+        file_entry = FileEntry(file_name, file_path, content_type)
+        self.all_files.append(file_entry)
+        return file_entry
+
+    def get_all_files(self):
+        return self.all_files
+
+
+def create_thumbnail_bytes(input_image_path, size=(128, 128)):
+    with Image.open(input_image_path) as img:
+        img.thumbnail(size)
+        byte_io = BytesIO()
+        img.save(byte_io, "JPEG")
+        byte_io.seek(0)
+        return byte_io.getvalue()