cleaner readme

Bumps [vite](https://github.com/vitejs/vite/tree/HEAD/packages/vite) from 5.1.4 to 5.1.5.
- [Release notes](https://github.com/vitejs/vite/releases)
- [Changelog](https://github.com/vitejs/vite/blob/main/packages/vite/CHANGELOG.md)
- [Commits](https://github.com/vitejs/vite/commits/v5.1.5/packages/vite)

---
updated-dependencies:
- dependency-name: vite
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/dependabot.yml

@@ -12,6 +12,12 @@ updates:
       interval: "weekly"
       day: "saturday"
       time: "09:00"
+  - package-ecosystem: "pip"
+    directory: "/example"
+    schedule:
+      interval: "weekly"
+      day: "saturday"
+      time: "09:00"
   - package-ecosystem: "github-actions"
     directory: "/.github/workflows/"
     schedule:

.github/workflows/autoupdate.yml

@@ -0,0 +1,35 @@
+on: "pull_request_target"
+
+permissions:
+  pull-requests: "write"
+  contents: "write"
+
+jobs:
+  dependabot:
+    runs-on: "ubuntu-latest"
+    # Checking the actor will prevent your Action run failing on non-Dependabot
+    # PRs but also ensures that it only does work for Dependabot PRs.
+    if: "${{ github.actor == 'dependabot[bot]' }}"
+    steps:
+      # This first step will fail if there's no metadata and so the approval
+      # will not occur.
+      - name: "Dependabot metadata"
+        id: "dependabot-metadata"
+        uses: "dependabot/fetch-metadata@v1"
+        with:
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+      # Here the PR gets approved.
+      - uses: "actions/checkout@v4"
+      - name: "Approve a PR"
+        run: "gh pr review --approve $PR_URL"
+        env:
+          PR_URL: "${{ github.event.pull_request.html_url }}"
+          GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+      # Finally, this sets the PR to allow auto-merging for patch and minor
+      # updates if all checks pass
+      - name: "Enable auto-merge for Dependabot PRs"
+        #if: "${{ steps.dependabot-metadata.outputs.update-type != 'version-update:semver-major' }}"
+        run: "gh pr merge --auto --squash $PR_URL"
+        env:
+          PR_URL: "${{ github.event.pull_request.html_url }}"
+          GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"

.github/workflows/build.yml

@@ -21,7 +21,7 @@ jobs:
       - uses: "actions/upload-artifact@v4"
         with:
           name: "frontend"
-          path: "./dist"
+          path: "dist"
           retention-days: 5
 
   build-backend:
@@ -29,35 +29,48 @@ jobs:
     runs-on: "ubuntu-latest"
     steps:
       - uses: "actions/checkout@v4"
-      - uses: "actions/setup-node@v4"
-        with:
-          cache: "yarn"
       - run: "pipx install poetry"
       - uses: "actions/setup-python@v5"
         with:
           python-version: "3.11"
           cache: "poetry"
-      - run: "poetry install"
+      - run: "SKIP_BUILD_FRONTEND=true poetry install"
-      - run: "poetry build"
+      - run: "SKIP_BUILD_FRONTEND=true poetry build"
 
   build-logo:
     name: "Build logo"
     runs-on: "ubuntu-latest"
     steps:
       - uses: "actions/checkout@v4"
-      - uses: "actions/setup-node@v4"
-        with:
-          cache: "yarn"
       - run: "pipx install poetry"
       - uses: "actions/setup-python@v5"
         with:
           python-version: "3.11"
           cache: "poetry"
-      - run: "poetry install"
+      - run: "SKIP_BUILD_FRONTEND=true poetry install"
       - run: "poetry run python yacv_server/logo.py"
       - run: "cp assets/fox.glb assets/logo_build/fox.glb"
       - uses: "actions/upload-artifact@v4"
         with:
           name: "logo"
-          path: "./assets/logo_build"
+          path: "assets/logo_build"
+          retention-days: 5
+
+  build-example:
+    name: "Build example"
+    runs-on: "ubuntu-latest"
+    steps:
+      - uses: "actions/checkout@v4"
+      - run: "pipx install poetry"
+      - uses: "actions/setup-python@v5"
+        with:
+          python-version: "3.11"
+          cache: "poetry"
+      - run: "SKIP_BUILD_FRONTEND=true poetry install"
+      - run: "PYTHONPATH=yacv_server YACV_STOP_EARLY=true poetry run python example/object.py"
+      - run: "mv export/object.glb export/example.glb"
+      - uses: "actions/upload-artifact@v4"
+        with:
+          name: "example"
+          path: "export"
           retention-days: 5

.github/workflows/deploy.yml

@@ -17,7 +17,9 @@ concurrency:
   cancel-in-progress: false
 
 jobs:
-  deploy:
+  # TODO: Update versions automatically
+
+  deploy-frontend:
     runs-on: "ubuntu-latest"
     environment:
       name: "github-pages"
@@ -35,18 +37,24 @@ jobs:
           name: "logo"
           path: "./public"
           allow_forks: false
-      - uses: "svenstaro/upload-release-action@v2"
+      - uses: "dawidd6/action-download-artifact@v3"
         with:
-          repo_token: "${{ secrets.GITHUB_TOKEN }}"
+          workflow: "build.yml"
-          file: "./public/*"
+          name: "example"
-          asset_name: "frontend"
+          path: "./public"
-          tag: "${{ github.ref }}"
+          allow_forks: false
-          overwrite: true
-          file_glob: true
       - uses: "actions/configure-pages@v4"
       - uses: "actions/upload-pages-artifact@v3"
         with:
           path: 'public'
       - id: "deployment"
         uses: "actions/deploy-pages@v4"
+      - run: 'zip -r frontend.zip public'
+      - uses: "svenstaro/upload-release-action@v2"
+        with:
+          repo_token: "${{ secrets.GITHUB_TOKEN }}"
+          file: "frontend.zip"
+          tag: "${{ github.ref }}"
+          overwrite: true
 
+  # TODO: deploy-backend

README.md

@@ -13,32 +13,16 @@ in a web browser.
 - View and interact with topological entities: faces, edges, vertices and locations.
 - Control clipping planes and transparency of each model.
 - Select any entity and measure bounding box size and distances.
-- Fully-featured [static deployment](#static-deployment): just upload the viewer and models to your server.
+- Fully-featured static deployment: just upload the viewer and models to your server.
-- [Live lazy updates](#live-updates) while editing the CAD model (using the `yacv-server` package).
+- Hot reloading while editing the CAD model (using the `yacv-server` package).
 
-## Usage & demo
+## Usage
 
-The [logo](yacv_server/logo.py) also works as an example of how to use the viewer.
+The [example](example) is a fully working project that shows how to use the viewer.
 
-### Live updates
+You can play with the latest
-
+demo [here](https://yeicor-3d.github.io/yet-another-cad-viewer/?preload=base.glb&preload=fox.glb&preload=img.jpg.glb&preload=location.glb)
-To see the live updates you will need to run the [yacv_server](yacv_server) and
+(or
-open [the viewer](https://yeicor-3d.github.io/yet-another-cad-viewer/) with
+[without animation](https://yeicor-3d.github.io/yet-another-cad-viewer/?autoplay=false&preload=base.glb&preload=fox.glb&preload=img.jpg.glb&preload=location.glb)).
-the `preloadModels=ws://<host>:32323/` query parameter (by default it already tries localhost).
-
-Note that [yacv_server](yacv_server) also hosts the frontend at `http://localhost:32323/` if you have no access to the
-internet.
-
-### Static deployment
-
-To deploy the viewer and models as a static website you can simply copy the latest build directory to your server.
-To load models use the `preloadModels=...` query parameter in the URL.
-It can be set multiple times to load multiple models.
-
-Note that you can simply reuse the [main deployment](https://yeicor-3d.github.io/yet-another-cad-viewer/) and host only
-your own models (linking them from the viewer with the `preloadModels` query parameter).
-
-To see a working example of a static deployment you can check out
-the [demo](https://yeicor-3d.github.io/yet-another-cad-viewer/?preloadModels=base.glb&preloadModels=fox.glb&preloadModels=img.jpg.glb&preloadModels=location.glb).
 
 ![Demo](assets/screenshot.png)

build.py

@@ -2,6 +2,7 @@ import os
 import subprocess
 
 if __name__ == "__main__":
+    if os.getenv('SKIP_BUILD_FRONTEND') is None:
         # When building the backend, make sure the frontend is built first
         subprocess.run(['yarn', 'install'], check=True)
         subprocess.run(['yarn', 'build', '--outDir', 'yacv_server/frontend'], check=True)

example/.gitignore

@@ -0,0 +1,2 @@
+/venv/
+/export/

example/README.md

@@ -0,0 +1,41 @@
+# Quickstart of Yet Another CAD Viewer
+
+## Installation
+
+1. Download the contents of this folder.
+2. Assuming you have a recent version of Python installed, install the required packages:
+
+```bash
+python -m venv venv
+pip install -r requirements.txt
+# Do this every time you change the terminal:
+. venv/bin/activate
+```
+
+## Usage
+
+### Development with hot-reloading
+
+To start the viewer, open the [GitHub Pages link](https://yeicor-3d.github.io/yet-another-cad-viewer/) of the frontend.
+It will try to connect to the server at `127.0.0.1:32323` by default (this can be changed with the `preload` query
+parameter).
+
+Running `python object.py` is enough to push the model to the viewer. However, the recommended way for developing with
+minimal latency is to run in cell mode (#%%). This way, the slow imports are only done once, and the server keeps
+running. After editing the file you can just re-run the cell with the `show_object` call to push the changes to
+the viewer.
+
+### Static final deployment
+
+Once your model is complete, you may want to share it with others using the same viewer.
+
+You can do so by exporting the model as a .glb file as a last step of your script.
+This is already done in `object.py` if the environment variable `CI` is set.
+
+Once you have the `object.glb` file, you can host it on any static file server and share the following link with others:
+`https://yeicor-3d.github.io/yet-another-cad-viewer/?preload=<link-to-object.glb>`
+
+For the example model, the build process is set up in [build.yml](../.github/workflows/build.yml), the upload process
+is set up in [deploy.yml](../.github/workflows/deploy.yml), and the final link is:
+https://yeicor-3d.github.io/yet-another-cad-viewer/?preload=example.glb
+

example/object.py

@@ -0,0 +1,25 @@
+import os
+
+from build123d import *  # Also works with cadquery objects!
+
+# Optional: enable logging to see what's happening
+import logging
+logging.basicConfig(level=logging.DEBUG)
+
+from yacv_server import show_object, export_all  # Check out all show_* methods for more features!
+
+# %%
+
+# Create a simple object
+with BuildPart() as obj:
+    Box(10, 10, 5)
+    Cylinder(4, 5, mode=Mode.SUBTRACT)
+
+# Show it in the frontend
+show_object(obj, 'object')
+
+# %%
+
+# If running on CI, export the object to a .glb file compatible with the frontend
+if 'CI' in os.environ:
+    export_all('export')

example/requirements.txt

@@ -0,0 +1,2 @@
+build123d
+yacv-server

frontend/App.vue

@@ -46,7 +46,7 @@ async function onModelRemoveRequest(name: string) {
 let networkMgr = new NetworkManager();
 networkMgr.addEventListener('update', (e) => onModelLoadRequest(e as NetworkUpdateEvent));
 // Start loading all configured models ASAP
-for (let model of settings.preloadModels) {
+for (let model of settings.preload) {
   networkMgr.load(model);
 }
 

frontend/misc/Loading.vue

@@ -6,7 +6,8 @@ import {VContainer, VRow, VCol, VProgressCircular} from "vuetify/lib/components/
   <v-container>
     <v-row justify="center" style="height: 100%">
       <v-col align-self="center">
-        <v-progress-circular indeterminate style="display: block; margin: 0 auto;"/>
+        <v-progress-circular indeterminate style="display: block; margin: 0 auto;"></v-progress-circular>
+        <slot/>
       </v-col>
     </v-row>
   </v-container>

frontend/misc/network.ts

@@ -24,8 +24,10 @@ export class NetworkManager extends EventTarget {
      * Updates will be emitted as "update" events, including the download URL and the model name.
      */
     async load(url: string) {
-        if (url.startsWith("ws://") || url.startsWith("wss://")) {
+        if (url.startsWith("dev+")) {
-            this.monitorWebSocket(url);
+            let baseUrl = new URL(url.slice(4));
+            baseUrl.searchParams.set("api_updates", "true");
+            this.monitorDevServer(baseUrl);
         } else {
             // Get the last part of the URL as the "name" of the model
             let name = url.split("/").pop();
@@ -38,21 +40,20 @@ export class NetworkManager extends EventTarget {
         }
     }
 
-    private monitorWebSocket(url: string) {
+    private monitorDevServer(url: URL) {
         // WARNING: This will spam the console logs with failed requests when the server is down
-        let ws = new WebSocket(url);
+        let eventSource = new EventSource(url);
-        ws.onmessage = (event) => {
+        eventSource.onmessage = (event) => {
             let data = JSON.parse(event.data);
             console.debug("WebSocket message", data);
             let urlObj = new URL(url);
-            urlObj.protocol = urlObj.protocol === "ws:" ? "http:" : "https:";
+            urlObj.searchParams.delete("api_updates");
             urlObj.searchParams.set("api_object", data.name);
             this.foundModel(data.name, data.hash, urlObj.toString());
         };
-        ws.onerror = () => ws.close();
+        eventSource.onerror = () => { // Retry after a very short delay
-        ws.onclose = () => setTimeout(() => this.monitorWebSocket(url), settings.monitorEveryMs);
+            setTimeout(() => this.monitorDevServer(url), settings.monitorEveryMs);
-        let timeoutFaster = setTimeout(() => ws.close(), settings.monitorOpenTimeoutMs);
+        }
-        ws.onopen = () => clearTimeout(timeoutFaster);
     }
 
     private foundModel(name: string, hash: string | null, url: string) {

frontend/misc/settings.ts

@@ -1,6 +1,6 @@
 // These are the default values for the settings, which are overridden below
 export const settings = {
-    preloadModels: [
+    preload: [
         // @ts-ignore
         // new URL('../../assets/fox.glb', import.meta.url).href,
         // @ts-ignore
@@ -10,11 +10,11 @@ export const settings = {
         // @ts-ignore
         // new URL('../../assets/logo_build/img.jpg.glb', import.meta.url).href,
         // Websocket URLs automatically listen for new models from the python backend
-        "ws://127.0.0.1:32323/"
+        "dev+http://127.0.0.1:32323/"
     ],
     displayLoadingEveryMs: 1000, /* How often to display partially loaded models */
     monitorEveryMs: 100,
-    monitorOpenTimeoutMs: 100,
+    monitorOpenTimeoutMs: 1000,
     // ModelViewer settings
     autoplay: true,
     arModes: 'webxr scene-viewer quick-look',
@@ -29,7 +29,8 @@ function parseSetting(name: string, value: string): any {
     if (arrayElem) name = name.slice(0, -2);
     let prevValue = (settings as any)[name];
     if (prevValue === undefined) throw new Error(`Unknown setting: ${name}`);
-    if (Array.isArray(prevValue) && !arrayElem) {
+    if (Array.isArray(prevValue)) {
+        if (!arrayElem) {
             let toExtend = []
             if (!firstTimeNames.includes(name)) {
                 firstTimeNames.push(name);
@@ -38,6 +39,9 @@ function parseSetting(name: string, value: string): any {
             }
             toExtend.push(parseSetting(name + ".0", value));
             return toExtend;
+        } else {
+            prevValue = prevValue[0];
+        }
     }
     switch (typeof prevValue) {
         case 'boolean':
@@ -47,7 +51,7 @@ function parseSetting(name: string, value: string): any {
         case 'string':
             return value;
         default:
-            throw new Error(`Unknown setting type: ${typeof prevValue}`);
+            throw new Error(`Unknown setting type: ${typeof prevValue} -- ${prevValue}`);
     }
 }
 

frontend/tools/Selection.vue

@@ -88,7 +88,7 @@ let selectionListener = (event: MouseEvent) => {
   // Find all hit objects and select the wanted one based on the filter
   const hits = raycaster.intersectObject(scene, true);
   let hit = hits.find((hit: Intersection<Object3D>) => {
-    if (!hit.object || !(hit.object as any).isMesh) return false;
+    if (!hit.object) return false;
     const kind = hit.object.type
     let isFace = kind === 'Mesh' || kind === 'SkinnedMesh';
     let isEdge = kind === 'Line' || kind === 'LineSegments';

frontend/viewer/ModelViewerWrapper.vue

@@ -1,12 +1,9 @@
-<script lang="ts">
-</script>
-
 <script setup lang="ts">
 import {settings} from "../misc/settings";
-import {onMounted, inject, type Ref} from "vue";
+import {inject, onMounted, type Ref, ref, watch} from "vue";
-import {$scene, $renderer} from "@google/model-viewer/lib/model-viewer-base";
+import {VList, VListItem} from "vuetify/lib/components/index.mjs";
+import {$renderer, $scene} from "@google/model-viewer/lib/model-viewer-base";
 import Loading from "../misc/Loading.vue";
-import {ref, watch} from "vue";
 import {ModelViewerElement} from '@google/model-viewer';
 import type {ModelScene} from "@google/model-viewer/lib/three-components/ModelScene";
 import {Hotspot} from "@google/model-viewer/lib/three-components/Hotspot";
@@ -152,7 +149,13 @@ watch(disableTap, (value) => {
                 :ar="settings.arModes.length > 0" :ar-modes="settings.arModes" :skybox-image="settings.background"
                 :environment-image="settings.background">
     <slot></slot> <!-- Controls, annotations, etc. -->
-    <loading class="annotation initial-load-banner"></loading>
+    <div class="annotation initial-load-banner">
+      Trying to load models from...
+      <v-list v-for="src in settings.preload" :key="src">
+        <v-list-item>{{ src }}</v-list-item>
+      </v-list>
+      <loading></loading>
+    </div>
   </model-viewer>
 
   <!-- The SVG overlay for fake 3D lines attached to the model -->
@@ -202,4 +205,15 @@ watch(disableTap, (value) => {
   height: 100dvh;
   pointer-events: none;
 }
+
+.initial-load-banner {
+  width: 300px;
+  margin: auto;
+  margin-top: 3em;
+  overflow: hidden;
+}
+
+.initial-load-banner .v-list-item {
+  overflow: hidden;
+}
 </style>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "yet-another-cad-viewer",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "",
   "license": "MIT",
   "author": "Yeicor <4929005+Yeicor@users.noreply.github.com>",
@@ -38,7 +38,7 @@
     "npm-run-all2": "^6.1.1",
     "terser": "^5.28.1",
     "typescript": "~5.3.0",
-    "vite": "^5.0.11",
+    "vite": "^5.1.5",
-    "vue-tsc": "^2.0.3"
+    "vue-tsc": "^2.0.5"
   }
 }

poetry.lock

@@ -128,6 +128,20 @@ devtools = ">=0.6"
 Pygments = ">=2.2.0"
 watchfiles = ">=0.10"
 
+[[package]]
+name = "aiohttp-sse"
+version = "2.2.0"
+description = "Server-sent events  support for aiohttp."
+optional = false
+python-versions = ">=3.8"
+files = [
+    {file = "aiohttp-sse-2.2.0.tar.gz", hash = "sha256:a48dd5774031d3f41a29e159ebdbb93e89c8f37c1e9e83e196296be51885a5c2"},
+    {file = "aiohttp_sse-2.2.0-py3-none-any.whl", hash = "sha256:339f9803bcf4682a2060e75548760d86abe4424a0d92ba66ff4985de3bd743dc"},
+]
+
+[package.dependencies]
+aiohttp = ">=3.0"
+
 [[package]]
 name = "aiosignal"
 version = "1.3.1"
@@ -1685,4 +1699,4 @@ multidict = ">=4.0"
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.9"
-content-hash = "b319fd1a01b16c61a1e5a3050a22e4898d8faea9ab85de6ae4bc82849b1a4025"
+content-hash = "734e26c5b174a1b5d0942e9b67d6fff679e1e7e06c5f2fd9978911befc9aec3c"

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "yacv-server"
-version = "0.1.0"  # TODO: Update automatically by CI on release (also for package.json!)
+version = "0.2.0"  # TODO: Update automatically by CI on release (also for package.json!)
 description = "Yet Another CAD Viewer (server)"
 authors = ["Yeicor <4929005+Yeicor@users.noreply.github.com>"]
 license = "MIT"
@@ -19,6 +19,7 @@ ocp-tessellate = "^2.0.6"
 
 # Web
 aiohttp = "^3.9.3"
+aiohttp-sse = "^2.2.0"
 aiohttp-cors = "^0.7.0"
 aiohttp-devtools = "^1.1.2"
 

vite.config.ts

@@ -6,6 +6,7 @@ import vueJsx from '@vitejs/plugin-vue-jsx'
 
 // https://vitejs.dev/config/
 export default defineConfig({
+    base: "",
     plugins: [
         vue({
             template: {

yacv_server/__init__.py

@@ -3,7 +3,6 @@ import os
 import time
 
 from aiohttp import web
-from build123d import Vector
 
 from server import Server
 
@@ -21,6 +20,7 @@ show = server.show
 show_object = show
 show_image = server.show_image
 show_all = server.show_cad_all
+export_all = server.export_all
 
 
 def _get_app() -> web.Application:

yacv_server/pubsub.py

@@ -62,3 +62,7 @@ class BufferedPubSub(Generic[T]):
     def buffer(self) -> List[T]:
         """Returns a shallow copy of the list of buffered events"""
         return self._buffer[:]
+
+    def delete(self, event: T):
+        """Deletes an event from the buffer"""
+        self._buffer.remove(event)

yacv_server/server.py

@@ -12,6 +12,7 @@ import aiohttp_cors
 from OCP.TopLoc import TopLoc_Location
 from OCP.TopoDS import TopoDS_Shape
 from aiohttp import web
+from aiohttp_sse import sse_response
 from build123d import Shape, Axis, Location, Vector
 from dataclasses_json import dataclass_json
 
@@ -28,6 +29,7 @@ if not os.path.exists(FRONTEND_BASE_PATH):
         FRONTEND_BASE_PATH = os.path.join(FILE_DIR, '..', 'dist')
     else:
         logger.warning('Frontend not found at %s', FRONTEND_BASE_PATH)
+        FRONTEND_BASE_PATH = None
 
 # Define the API paths (also available at the root path for simplicity)
 UPDATES_API_PATH = '/api/updates'
@@ -58,6 +60,7 @@ class UpdatesApiFullData(UpdatesApiData):
         self.kwargs = kwargs
 
     def to_json(self) -> str:
+        # noinspection PyUnresolvedReferences
         return super().to_json()
 
 
@@ -70,10 +73,13 @@ class Server:
     app = web.Application()
     runner: web.AppRunner
     thread: Optional[Thread] = None
+    startup_complete = asyncio.Event()
     do_shutdown = asyncio.Event()
+    at_least_one_client = asyncio.Event()
     show_events = BufferedPubSub[UpdatesApiFullData]()
     object_events: Dict[str, BufferedPubSub[bytes]] = {}
     object_events_lock = asyncio.Lock()
+    frontend_lock = asyncio.Lock()  # To avoid exiting too early while frontend makes requests
 
     def __init__(self, *args, **kwargs):
         # --- Routes ---
@@ -84,6 +90,7 @@ class Server:
         self.app.router.add_get('/', self._entrypoint)
         # - Static files from the frontend
         self.app.router.add_get('/{path:(.*/|)}', _index_handler)  # Any folder -> index.html
+        if FRONTEND_BASE_PATH is not None:
             self.app.router.add_static('/', path=FRONTEND_BASE_PATH, name='static_frontend')
         # --- CORS ---
         cors = aiohttp_cors.setup(self.app, defaults={
@@ -106,6 +113,11 @@ class Server:
         signal.signal(signal.SIGINT | signal.SIGTERM, self.stop)
         atexit.register(self.stop)
         self.thread.start()
+        logger.info('Server started (requested)...')
+        # Wait for the server to be ready before returning
+        while not self.startup_complete.is_set():
+            time.sleep(0.01)
+        logger.info('Server started (received)...')
 
     # noinspection PyUnusedLocal
     def stop(self, *args):
@@ -113,10 +125,31 @@ class Server:
         if self.thread is None:
             print('Cannot stop server because it is not running')
             return
-        # FIXME: Wait for at least one client to confirm ready before stopping in case we are too fast?
+
+        if os.getenv('YACV_STOP_EARLY', '') == '':
+            # Make sure we can hold the lock for more than 100ms (to avoid exiting too early)
+            logger.info('Stopping server (waiting for at least one frontend request first, cancel with CTRL+C)...')
+            try:
+                while not self.at_least_one_client.is_set():
+                    time.sleep(0.01)
+            except KeyboardInterrupt:
+                pass
+
+            logger.info('Stopping server (waiting for no more frontend requests)...')
+            acquired = time.time()
+            while time.time() - acquired < 1.0:
+                if self.frontend_lock.locked():
+                    acquired = time.time()
+                time.sleep(0.01)
+
+        # Stop the server in the background
         self.loop.call_soon_threadsafe(lambda *a: self.do_shutdown.set())
-        self.thread.join(timeout=12)
+        logger.info('Stopping server (sent)...')
+
+        # Wait for the server to stop gracefully
+        self.thread.join(timeout=30)
         self.thread = None
+        logger.info('Stopping server (confirmed)...')
         if len(args) >= 1 and args[0] in (signal.SIGINT, signal.SIGTERM):
             sys.exit(0)  # Exit with success
 
@@ -133,15 +166,18 @@ class Server:
         await runner.setup()
         site = web.TCPSite(runner, os.getenv('YACV_HOST', 'localhost'), int(os.getenv('YACV_PORT', 32323)))
         await site.start()
-        # print(f'Server started at {site.name}')
+        logger.info('Server started (sent)...')
+        self.startup_complete.set()
         # Wait for a signal to stop the server while running
         await self.do_shutdown.wait()
-        # print('Shutting down server...')
+        logger.info('Stopping server (received)...')
-        await runner.cleanup()
+        await runner.shutdown()
+        # await runner.cleanup()  # Gets stuck?
+        logger.info('Stopping server (done)...')
 
     async def _entrypoint(self, request: web.Request) -> web.StreamResponse:
         """Main entrypoint to the server, which automatically serves the frontend/updates/objects"""
-        if request.headers.get('Upgrade', '').lower() == 'websocket':  # WebSocket -> updates API
+        if request.query.get('api_updates', '') != '':  # ?api_updates -> updates API
             return await self._api_updates(request)
         elif request.query.get('api_object', '') != '':  # ?api_object={name} -> object API
             request.match_info['name'] = request.query['api_object']
@@ -149,36 +185,32 @@ class Server:
         else:  # Anything else -> frontend index.html
             return await _index_handler(request)
 
-    async def _api_updates(self, request: web.Request) -> web.WebSocketResponse:
+    async def _api_updates(self, request: web.Request) -> web.StreamResponse:
         """Handles a publish-only websocket connection that send show_object events along with their hashes and URLs"""
-        ws = web.WebSocketResponse()
+        self.at_least_one_client.set()
-        await ws.prepare(request)
+        async with sse_response(request) as resp:
+            logger.debug('Client connected: %s', request.remote)
+            resp.ping_interval = 0.1  # HACK: forces flushing of the buffer
 
-        async def _send_api_updates():
+            # Send buffered events first, while keeping a lock
-            subscription = self.show_events.subscribe()
+            async with self.frontend_lock:
+                for data in self.show_events.buffer():
+                    logger.debug('Sending info about %s to %s: %s', data.name, request.remote, data)
+                    # noinspection PyUnresolvedReferences
+                    await resp.send(data.to_json())
+
+            # Send future events over the same connection
+            subscription = self.show_events.subscribe(include_buffered=False)
             try:
                 async for data in subscription:
                     logger.debug('Sending info about %s to %s: %s', data.name, request.remote, data)
                     # noinspection PyUnresolvedReferences
-                    await ws.send_str(data.to_json())
+                    await resp.send(data.to_json())
             finally:
                 await subscription.aclose()
-
-        # Start sending updates to the client automatically
-        send_task = asyncio.create_task(_send_api_updates())
-        receive_task = asyncio.create_task(ws.receive())
-        try:
-            logger.debug('Client connected: %s', request.remote)
-            # Wait for the client to close the connection (or send a message)
-            done, pending = await asyncio.wait([send_task, receive_task], return_when=asyncio.FIRST_COMPLETED)
-            # Make sure to stop sending updates to the client and close the connection
-            for task in pending:
-                task.cancel()
-        finally:
-            await ws.close()
                 logger.debug('Client disconnected: %s', request.remote)
 
-        return ws
+        return resp
 
     obj_counter = 0
 
@@ -186,6 +218,13 @@ class Server:
                      kwargs=None):
         name = name or f'object_{self.obj_counter}'
         self.obj_counter += 1
+        # Remove a previous object with the same name
+        for old_event in self.show_events.buffer():
+            if old_event.name == name:
+                self.show_events.delete(old_event)
+                if name in self.object_events:
+                    del self.object_events[name]
+                break
         precomputed_info = UpdatesApiFullData(name=name, hash=hash, obj=obj, kwargs=kwargs or {})
         self.show_events.publish_nowait(precomputed_info)
         logger.info('show_object(%s, %s) took %.3f seconds', name, hash, time.time() - start)
@@ -243,6 +282,7 @@ class Server:
 
     async def _api_object(self, request: web.Request) -> web.Response:
         """Returns the object file with the matching name, building it if necessary."""
+        async with self.frontend_lock:
             # Export the object (or fail if not found)
             exported_glb = await self.export(request.match_info['name'])
 
@@ -256,22 +296,20 @@ class Server:
         """Returns the names of all objects that have been shown"""
         return list([obj.name for obj in self.show_events.buffer()])
 
+    def _shown_object(self, name: str) -> Optional[UpdatesApiFullData]:
+        """Returns the object with the given name, if it exists"""
+        for obj in self.show_events.buffer():
+            if obj.name == name:
+                return obj
+        return None
+
     async def export(self, name: str) -> bytes:
         """Export the given previously-shown object to a single GLB file, building it if necessary."""
         start = time.time()
 
         # Check that the object to build exists and grab it if it does
-        found = False
+        event = self._shown_object(name)
-        obj: Optional[TopoDS_Shape] = None
+        if not event:
-        kwargs: Optional[Dict[str, any]] = None
-        subscription = self.show_events.buffer()
-        for data in subscription:
-            if data.name == name:
-                obj = data.obj
-                kwargs = data.kwargs
-                found = True  # Required because obj could be None
-                break
-        if not found:
             raise web.HTTPNotFound(text=f'No object named {name} was previously shown')
 
         # Use the lock to ensure that we don't build the object twice
@@ -284,19 +322,21 @@ class Server:
 
                 def _build_object():
                     # Build and publish the object (once)
-                    gltf = tessellate(obj, tolerance=kwargs.get('tolerance', 0.1),
+                    gltf = tessellate(event.obj, tolerance=event.kwargs.get('tolerance', 0.1),
-                                      angular_tolerance=kwargs.get('angular_tolerance', 0.1),
+                                      angular_tolerance=event.kwargs.get('angular_tolerance', 0.1),
-                                      faces=kwargs.get('faces', True),
+                                      faces=event.kwargs.get('faces', True),
-                                      edges=kwargs.get('edges', True),
+                                      edges=event.kwargs.get('edges', True),
-                                      vertices=kwargs.get('vertices', True))
+                                      vertices=event.kwargs.get('vertices', True))
                     glb_list_of_bytes = gltf.save_to_bytes()
                     publish_to.publish_nowait(b''.join(glb_list_of_bytes))
                     logger.info('export(%s) took %.3f seconds, %d parts', name, time.time() - start,
                                 len(gltf.meshes[0].primitives))
 
-                # We should build it fully even if we are cancelled, so we use a separate task
+                # await asyncio.get_running_loop().run_in_executor(None, _build_object)
-                # Furthermore, building is CPU-bound, so we use the default executor
+                # The previous line has problems with auto-closed loop on script exit
-                await asyncio.get_running_loop().run_in_executor(None, _build_object)
+                # and is cancellable, so instead run blocking code in async context :(
+                logger.debug('Building object %s... %s', name, event.obj)
+                _build_object()
 
         # In either case return the elements of a subscription to the async generator
         subscription = self.object_events[name].subscribe()
@@ -304,3 +344,15 @@ class Server:
             return await anext(subscription)
         finally:
             await subscription.aclose()
+
+    def export_all(self, folder: str) -> None:
+        """Export all previously-shown objects to GLB files in the given folder"""
+        import asyncio
+
+        async def _export_all():
+            os.makedirs(folder, exist_ok=True)
+            for name in self.shown_object_names():
+                with open(os.path.join(folder, f'{name}.glb'), 'wb') as f:
+                    f.write(await self.export(name))
+
+        asyncio.run(_export_all())

yarn.lock

@@ -851,26 +851,26 @@
   resolved "https://registry.yarnpkg.com/@vitejs/plugin-vue/-/plugin-vue-5.0.4.tgz#508d6a0f2440f86945835d903fcc0d95d1bb8a37"
   integrity sha512-WS3hevEszI6CEVEx28F8RjTX97k3KsrcY6kvTg7+Whm5y3oYvcqzVeGCU3hxSAn4uY2CLCkeokkGKpoctccilQ==
 
-"@volar/language-core@2.1.0", "@volar/language-core@~2.1.0":
+"@volar/language-core@2.1.1", "@volar/language-core@~2.1.1":
-  version "2.1.0"
+  version "2.1.1"
-  resolved "https://registry.yarnpkg.com/@volar/language-core/-/language-core-2.1.0.tgz#26953a62f5d956a4ba4003faf59ae09b2a8aabb6"
+  resolved "https://registry.yarnpkg.com/@volar/language-core/-/language-core-2.1.1.tgz#ea7c2448ac5bdb2dd2ed202e5ff57929cb8ef191"
-  integrity sha512-BrYEgYHx92ocpt1OUxJs2x3TAXEjpPLxsQoARb96g2GdF62xnfRQUqCNBwiU7Z3MQ/0tOAdqdHNYNmrFtx6q4A==
+  integrity sha512-oVbZcj97+5zlowkHMSJMt3aaAFuFyhXeXoOEHcqGECxFvw1TPCNnMM9vxhqNpoiNeWKHvggoq9WCk/HzJHtP8A==
   dependencies:
-    "@volar/source-map" "2.1.0"
+    "@volar/source-map" "2.1.1"
 
-"@volar/source-map@2.1.0":
+"@volar/source-map@2.1.1":
-  version "2.1.0"
+  version "2.1.1"
-  resolved "https://registry.yarnpkg.com/@volar/source-map/-/source-map-2.1.0.tgz#f8c70b5043ae4a3d2cbd66a84036ef030b655a8e"
+  resolved "https://registry.yarnpkg.com/@volar/source-map/-/source-map-2.1.1.tgz#9ca00177177417496a0364cea2f965445e19abb2"
-  integrity sha512-VPyi+DTv67cvUOkUewzsOQJY3VUhjOjQxigT487z/H7tEI8ZFd5RksC5afk3JelOK+a/3Y8LRDbKmYKu1dz87g==
+  integrity sha512-OOtxrEWB2eZ+tnCy5JwDkcCPGlN3+ioNNzkywXE9k4XA7p4cN36frR7QPAOksvd7RXKUGHzSjq6XrYnTPa4z4Q==
   dependencies:
     muggle-string "^0.4.0"
 
-"@volar/typescript@~2.1.0":
+"@volar/typescript@~2.1.1":
-  version "2.1.0"
+  version "2.1.1"
-  resolved "https://registry.yarnpkg.com/@volar/typescript/-/typescript-2.1.0.tgz#640abcdcb6b822f9860006d090e1d5252c655e37"
+  resolved "https://registry.yarnpkg.com/@volar/typescript/-/typescript-2.1.1.tgz#b3dddaf39140cc0e00d67bad943496e2470a3882"
-  integrity sha512-2cicVoW4q6eU/omqfOBv+6r9JdrF5bBelujbJhayPNKiOj/xwotSJ/DM8IeMvTZvtkOZkm6suyOCLEokLY0w2w==
+  integrity sha512-5K41AWvFZCMMKZCx8bbFvbkyiKHr0s9k8P0M1FVXLX/9HYHzK5C9B8cX4uhATSehAytFIRnR4fTXVQtWp/Yzag==
   dependencies:
-    "@volar/language-core" "2.1.0"
+    "@volar/language-core" "2.1.1"
     path-browserify "^1.0.1"
 
 "@vue/babel-helper-vue-transform-on@1.2.1":
@@ -948,12 +948,12 @@
     "@vue/compiler-dom" "3.4.21"
     "@vue/shared" "3.4.21"
 
-"@vue/language-core@2.0.3":
+"@vue/language-core@2.0.5":
-  version "2.0.3"
+  version "2.0.5"
-  resolved "https://registry.yarnpkg.com/@vue/language-core/-/language-core-2.0.3.tgz#49e290c928b216a5b0f07012ff6e1065a6e15258"
+  resolved "https://registry.yarnpkg.com/@vue/language-core/-/language-core-2.0.5.tgz#bd3502604ea785f4171815005997988563f18469"
-  integrity sha512-hnVF/Q3cD2v+EFD4pD1YdITGBcdM38P18SYqilVQDezKw5RobWny4BwIckWGS1fJmUstsO9mTX30ZOyzyR2Q+Q==
+  integrity sha512-knGXuQqhDSO7QJr8LFklsiWa23N2ikehkdVxtc9UKgnyqsnusughS2Tkg7VN8Hqed35X0B52Z+OGI5OrT/8uxQ==
   dependencies:
-    "@volar/language-core" "~2.1.0"
+    "@volar/language-core" "~2.1.1"
     "@vue/compiler-dom" "^3.4.0"
     "@vue/shared" "^3.4.0"
     computeds "^0.0.1"
@@ -2992,10 +2992,10 @@ validate-npm-package-name@^5.0.0:
   dependencies:
     builtins "^5.0.0"
 
-vite@^5.0.11:
+vite@^5.1.5:
-  version "5.1.4"
+  version "5.1.5"
-  resolved "https://registry.yarnpkg.com/vite/-/vite-5.1.4.tgz#14e9d3e7a6e488f36284ef13cebe149f060bcfb6"
+  resolved "https://registry.yarnpkg.com/vite/-/vite-5.1.5.tgz#bdbc2b15e8000d9cc5172f059201178f9c9de5fb"
-  integrity sha512-n+MPqzq+d9nMVTKyewqw6kSt+R3CkvF9QAKY8obiQn8g1fwTscKxyfaYnC632HtBXAQGc1Yjomphwn1dtwGAHg==
+  integrity sha512-BdN1xh0Of/oQafhU+FvopafUp6WaYenLU/NFoL5WyJL++GxkNfieKzBhM24H3HVsPQrlAqB7iJYTHabzaRed5Q==
   dependencies:
     esbuild "^0.19.3"
     postcss "^8.4.35"
@@ -3011,13 +3011,13 @@ vue-template-compiler@^2.7.14:
     de-indent "^1.0.2"
     he "^1.2.0"
 
-vue-tsc@^2.0.3:
+vue-tsc@^2.0.5:
-  version "2.0.3"
+  version "2.0.5"
-  resolved "https://registry.yarnpkg.com/vue-tsc/-/vue-tsc-2.0.3.tgz#9b736f6ad478a5c98a23aeef509eb0b73d115b26"
+  resolved "https://registry.yarnpkg.com/vue-tsc/-/vue-tsc-2.0.5.tgz#f491e24d74fcbf50cc3a71fce5ac2c99ee6335d9"
-  integrity sha512-aMJqbgLiKDAwAglWqMoGf1Ez6Wwqhlk2MDxEjFGziiLW0A+tHOWE1+YQJZQ1Vm6zaENPA2KJAubFhaR988UvGg==
+  integrity sha512-e8WCgOVTrbmC04XPnI+IpaMTFYKaTm5s/MXFcvxO1l9kxzn+9FpGNVrBSlQE8VpTJaJg4kaBK1nj3NC20VJzjw==
   dependencies:
-    "@volar/typescript" "~2.1.0"
+    "@volar/typescript" "~2.1.1"
-    "@vue/language-core" "2.0.3"
+    "@vue/language-core" "2.0.5"
     semver "^7.5.4"
 
 vue@^3.4.21: