Can we use `.gjs` for route templates?

Development
6

If its just styling for an actually printed page, and you don’t mind the navbar and extra stuff when viewing the page, you can use @media print CSS selector to change the styling when printing. Discourse already hides a lot of things during print (discourse/app/assets/stylesheets/common/printer-friendly.scss at main · discourse/discourse · GitHub). You can preview the page using print media simulation mode in firefox’s inspect mode. There should be an equivalent feature in chrome’s inspect mode.

A developer is using an Inspect element tool in a web browser to examine the HTML code of the Dev Tourism website, with the "Can we use" website's dropdown menu displayed on the top-right. (Captioned by AI)
A developer is using an Inspect element tool in a web browser to examine the HTML code of the Dev Tourism website, with the "Can we use" website's dropdown menu displayed on the top-right. (Captioned by AI)1162×604 96.4 KB

If you need a complete blank canvas to work with, not just in the print mode but also in normal web browsing, you can use a bit of CSS trickery.
Suppose your glimmer component has a root div with id="print-component__root", we can let CSS check for its existence with a :has() selector (or just add/remove a class to body from the glimmer component lifecycle), and selectively apply styling.

body:has(#print-component__root) {
  header,
  .avatar,
  .sidebar-wrapper,
  ... {
    all: unset !important;  // all: unset might be a bit too aggressive
    display: none !important;
  }
}

#print-component__root {
  // normal styling
}

There might be a better, cleaner way that would actually remove the DOM elements, but the CSS is a good workaround to reset everything.