Files
homelable/backend/app/api/routes/canvas.py
T
Pouzor bf8551015c feat(canvas): distinguish new user from cleared canvas; stop demo on backend error
Cleared canvas re-showed the demo, and backend errors silently fell back to
demo — hiding real outages and forcing users to wipe demo nodes before bulk
edits. Now:
- backend load reports `initialized` (CanvasState row exists = ever saved)
- decideCanvasLoad() picks real | empty | demo; empty is kept empty
- backend down/error shows an error banner + toast, never the demo
- data-new-user flag reserved as the Getting Started walkthrough hook

ha-relevant: yes
2026-07-18 23:02:44 +02:00

110 lines
4.2 KiB
Python

import uuid
from datetime import datetime, timezone
from typing import Any
from fastapi import APIRouter, Depends, Query
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from app.api.deps import get_current_user
from app.db.database import get_db
from app.db.models import CanvasState, Design, Edge, Node
from app.schemas.canvas import CanvasSaveRequest, CanvasStateResponse
from app.schemas.edges import EdgeResponse
from app.schemas.nodes import NodeResponse
router = APIRouter()
@router.get("", response_model=CanvasStateResponse)
async def load_canvas(
design_id: str | None = Query(None, description="Design ID to load; uses first design if omitted"),
db: AsyncSession = Depends(get_db),
_: str = Depends(get_current_user),
) -> CanvasStateResponse:
if design_id is None:
first = (await db.execute(select(Design).order_by(Design.created_at).limit(1))).scalar()
design_id = first.id if first else None
if design_id is None:
return CanvasStateResponse(nodes=[], edges=[], viewport={"x": 0, "y": 0, "zoom": 1}, custom_style=None)
nodes = (await db.execute(select(Node).where(Node.design_id == design_id))).scalars().all()
edges = (await db.execute(select(Edge).where(Edge.design_id == design_id))).scalars().all()
state = await db.get(CanvasState, design_id)
viewport: dict[str, Any] = state.viewport if state else {"x": 0, "y": 0, "zoom": 1}
return CanvasStateResponse(
nodes=[NodeResponse.model_validate(n) for n in nodes],
edges=[EdgeResponse.model_validate(e) for e in edges],
viewport=viewport,
custom_style=state.custom_style if state else None,
# A CanvasState row exists only after a save (or explicit design create),
# so its presence marks an intentional canvas vs. a never-touched one.
initialized=state is not None,
)
@router.post("/save")
async def save_canvas(
body: CanvasSaveRequest, db: AsyncSession = Depends(get_db), _: str = Depends(get_current_user)
) -> dict[str, bool | str]:
design_id = body.design_id
if design_id is None:
first = (await db.execute(select(Design).order_by(Design.created_at).limit(1))).scalar()
design_id = first.id if first else None
if design_id is None:
new_design = Design(id=str(uuid.uuid4()), name="Network Topology", design_type="network")
db.add(new_design)
await db.flush()
design_id = new_design.id
incoming_node_ids = {n.id for n in body.nodes}
incoming_edge_ids = {e.id for e in body.edges}
# Delete nodes removed from canvas (only within this design)
existing_nodes = (await db.execute(select(Node).where(Node.design_id == design_id))).scalars().all()
for node in existing_nodes:
if node.id not in incoming_node_ids:
await db.delete(node)
# Delete edges removed from canvas (only within this design)
existing_edges = (await db.execute(select(Edge).where(Edge.design_id == design_id))).scalars().all()
for edge in existing_edges:
if edge.id not in incoming_edge_ids:
await db.delete(edge)
await db.flush()
# Upsert nodes
for node_data in body.nodes:
db_node = await db.get(Node, node_data.id)
payload = node_data.model_dump()
payload["design_id"] = design_id
if db_node:
for field, value in payload.items():
setattr(db_node, field, value)
else:
db.add(Node(**payload))
# Upsert edges
for edge_data in body.edges:
db_edge = await db.get(Edge, edge_data.id)
payload = edge_data.model_dump()
payload["design_id"] = design_id
if db_edge:
for field, value in payload.items():
setattr(db_edge, field, value)
else:
db.add(Edge(**payload))
# Upsert viewport + custom style
state = await db.get(CanvasState, design_id)
if state:
state.viewport = body.viewport
state.custom_style = body.custom_style
state.saved_at = datetime.now(timezone.utc)
else:
db.add(CanvasState(design_id=design_id, viewport=body.viewport, custom_style=body.custom_style))
await db.commit()
return {"saved": True}