theseus/home-preload.js

// Preload for tab webContents that host the built-in home page. All non-
// settings tabs get this preload since we don't know in advance whether a
// tab will land on home.html; the corresponding IPC handlers in main.js
// validate the sender's URL is our own home.html file:// and reject any
// origin-mismatched call, so a third-party page can inspect the API's
// SHAPE but can't invoke it against local user data.
const { contextBridge, ipcRenderer } = require("electron");
contextBridge.exposeInMainWorld("home", {
  getCards: () => ipcRenderer.invoke("home-cards-get"),
  setCards: (cards) => ipcRenderer.invoke("home-cards-set", cards),
  resetCards: () => ipcRenderer.invoke("home-cards-reset"),
  navigate: (url) => ipcRenderer.invoke("navigate", url),
  // Main pushes an updated list here after a successful remote refresh
  // (only when the user has not customised locally). home.html re-renders.
  onCards: (cb) => ipcRenderer.on("home-cards", (_e, list) => cb(list)),
});
// Same preload also serves the branded error page (error.html). Handlers in
// main.js sender-check for error.html so a random page seeing the API shape
// can't drive navigation.
contextBridge.exposeInMainWorld("errorpage", {
  retry:      (url)  => ipcRenderer.invoke("error-retry", url),
  goHome:     ()     => ipcRenderer.invoke("error-home"),
  searchFor:  (text) => ipcRenderer.invoke("error-search", text),
  registerOnSirius: (host) => ipcRenderer.invoke("error-register", host),
  openExternal:     (url)  => ipcRenderer.invoke("error-open-external", url),
});