Apphost file uploads

You can always skip defining payload in a Practicus AI apphost API handler and use Starlette Request object instead.

This can be used for file uploads, handling streaming requests and more.

Handling file uploads

from pathlib import Path
from starlette.requests import Request
from starlette.responses import JSONResponse

import practicuscore as prt


@prt.api("/upload-file", spec=api_spec)
async def handle_upload_file(request: Request):
    form = await request.form()  # parses multipart/form-data
    upload_file = form.get("file")  # name="file" in the HTML form

    if upload_file is None:
        return JSONResponse({"error": "missing form field 'file'"}, status_code=400)

    # Starlette UploadFile
    filename: str = upload_file.filename or "unknown"
    content_type: str = upload_file.content_type or "application/octet-stream"

    # read bytes (ok for small/medium files)
    file_bytes: bytes = await upload_file.read()

    return JSONResponse(
        {
            "filename": filename,
            "content_type": content_type,
            "size_bytes": len(file_bytes),
        }
    )


# Save upload to disk without loading whole file into memory

@prt.api("/upload-file2", spec=api_spec)
async def handle_upload_file2(request: Request) -> JSONResponse:
    form = await request.form()
    upload_file = form.get("file")
    if upload_file is None:
        return JSONResponse({"error": "missing form field 'file'"}, status_code=400)

    uploads_dir: Path = Path("/tmp/uploads")
    uploads_dir.mkdir(parents=True, exist_ok=True)

    safe_name: str = (upload_file.filename or "upload.bin").replace("/", "_")
    target_path: Path = uploads_dir / safe_name

    bytes_written: int = 0
    with target_path.open("wb") as output_fp:
        while True:
            chunk: bytes = await upload_file.read(1024 * 1024)  # 1 MiB
            if not chunk:
                break
            output_fp.write(chunk)
            bytes_written += len(chunk)

    return JSONResponse({"saved_as": str(target_path), "size_bytes": bytes_written})

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