Open external links in an Electron app using the system browser

For Datasette.app I wanted to ensure that links to external URLs would open in the system browser.

This recipe works:

function postConfigure(window) {
  window.webContents.on("will-navigate", function (event, reqUrl) {
    let requestedHost = new URL(reqUrl).host;
    let currentHost = new URL(window.webContents.getURL()).host;
    if (requestedHost && requestedHost != currentHost) {
      event.preventDefault();
      shell.openExternal(reqUrl);
    }
  });
}

The will-navigate event fires before any in-browser navigations, which means they can be intercepted and cancelled if necessary.

I use the URL() class to extract the .host so I can check if the host being navigated to differs from the host that the application is running against (which is probably localhost:$port).

Initially I was using require('url').URL for this but that doesn't appear to be necessary - Node.js ships with URL as a top-level class these days.

event.preventDefault() cancels the navigation and shell.openExternal(reqUrl) opens the URL using the system default browsner.

I call this function on any new window I create using new BrowserWindow - for example:

mainWindow = new BrowserWindow({
  width: 800,
  height: 600,
  show: false,
});
mainWindow.loadFile("loading.html");
mainWindow.once("ready-to-show", () => {
  mainWindow.show();
});
postConfigure(mainWindow);

Related

Created 2021-09-02T14:15:19-07:00 · Edit