Hacktoberfest 2026: le issue che i maintainer hanno segnato per ottobre, aperte e adatte ai principianti. Sfoglia le issue Hacktoberfest

Lazy loading (level 3) for a browser host: load later parts through the host

Aperta
  • Qualcosa non va?
#1,278 0 commenti 0 reazioni 0 assegnatari Vedi su GitHub

I maintainer di solito rispondono entro 1 giorno

Nessuno ha ancora preso questa issue.

Valutazione

Difficoltà
5/5
Tempo stimato
Più di una settimana
Idoneità per principianti
35/100
Tipo di issue
Funzionalità
Chiarezza
Specificata chiaramente
Stato di attività
Attiva
Stack tecnologico
cpp, html, wasm
Ambito
api, backend, web-dev

Direzione di ricerca

Read docs/design/lazy-loading.md decision 2, then trace load(chunk) in viewport.js, HtmlService::write(path), and the wasm binding in wasm/src/wasm_html.cpp (to_html_config) and wasm/js/index.d.ts. The report describes the host bridge, per-document path writing, wasm config, and sandbox constraints; completion means browser hosts can load later parts on demand while file and HTTP loading still work.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Descrizione

What is missing

With HtmlConfig::lazy_loading, a page loads each later part of a view as a script beside it: text-chunks/<n>.js, sheet<n>-chunks/<m>.js, pdf-pages/<n>.js, and the search index (*-search/<n>.js). viewport.js adds a <script src> with a relative path (docs/design/lazy-loading.md decision 2). That works from file:// and over the HTTP server.

A browser host cannot use it. The website (opendocument.app, on @opendocument/odr-core through wasm) renders into a sandboxed srcdoc iframe:

  • sandbox="allow-scripts" without allow-same-origin, so the frame has no origin
  • CSP script-src 'self' 'wasm-unsafe-eval' 'unsafe-inline', connect-src 'self'
  • no file server

A relative <script src> has nowhere to load from there. The wasm binding also does not read lazyLoading (wasm/src/wasm_html.cpp, to_html_config; wasm/js/index.d.ts). So in 7.6.x a browser host gets level 1 (lazyLayout) only.

What it would take

  1. A host hook in viewport.js. When the page has a host to ask, load(chunk) asks the host for the part named by data-odr-chunk-src (and data-odr-chunk-text for the index) instead of adding a <script src>. For example: post {type: "loadPart", path} through the host bridge, and accept the answer as the script text, or as the html of the part, passed to odr.chunks.fill and odr.chunks.text. The script tag stays the default, so file:// and HTTP do not change.
  2. A wasm call that writes a path. C++ has HtmlService::write(path) (and exists, mimetype), and it renders a part on demand. The wasm binding does not expose it. Something like doc.write(path) returning the text, kept per open document, so the host can answer the hook.
  3. lazyLoading in the wasm config, with the hook as its precondition. The README and index.d.ts should say so.
  4. The sandbox: the answer must reach the frame without allow-same-origin. postMessage into the frame and eval-free insertion fit the site's CSP, because odr.chunks.fill takes html, not code.

Why

The site caps a sheet at 50,000 cells, because the whole markup goes into srcdoc as one string. Level 3 would let it show far larger files: the page holds only the first part, and the rest comes from the open document on demand. It is the same win as on the server: for Core_v5.1.pdf, 1.4 MB instead of 127 MB.

Reported by the website session after moving the site to 7.6.0.

Lingua principale
C++
Stelle
41
Fork
10
Merge medio
10h 30m
PR unite (30g)
342

Preparare l'ambiente

Questo progetto non fornisce container di sviluppo, Dockerfile né guida per i contributori, quindi l'ambiente è a tuo carico: parti dal suo README e consulta la nostra guida al primo contributo per i passaggi generali.

Come iniziare

  1. Leggi tutta la issue e poi la guida ai contributi del progetto.
  2. Commenta sulla issue per dire che te ne occupi tu — evita che due persone facciano lo stesso lavoro.
  3. Fai un fork del repository e lavora su un branch.
  4. Apri una pull request che faccia riferimento al numero della issue.

Altre issue di opendocument-app/OpenDocument.core

Tutte le issue di opendocument-app/OpenDocument.core

Issue simili

Altre issue su C++

Ricevi le nuove issue nella tua casella

Un breve riepilogo di issue GitHub adatte ai principianti.