queryFlag / isInIframe

Read a boolean URL flag, and tell whether the page is embedded — the two checks behind ?embed, ?readonly and ?debug.

API

Function	Description
queryFlag(key, url?)	Whether a query parameter reads as true
isInIframe()	Whether this page is running inside an iframe; false under SSR

queryFlag

Parameter	Description	Type	Default
key	Parameter name	string	Required
url	Full URL or query string	string	Current location

True for ?k, ?k=, ?k=1 and ?k=true (case-insensitive). False for everything else, including an absent parameter and an explicit ?k=false.

Example

Read a flag

import { queryFlag } from 'ranuts';

queryFlag('embed', '?embed'); // true  ← the usual spelling
queryFlag('embed', '?embed=1'); // true
queryFlag('embed', '?embed=true'); // true
queryFlag('embed', '?embed=false'); // false
queryFlag('embed', '?lang=en'); // false

Detect embed mode

import { queryFlag, isInIframe } from 'ranuts';

// Embedded when framed, or when the host asked for it explicitly.
const embedded = isInIframe() || queryFlag('embed') || queryFlag('embedded');

if (embedded) {
  document.body.classList.add('embed-mode');
}

Skip analytics inside someone else's page

import { isInIframe } from 'ranuts';

// Tracking here would attribute the host site's visitors to us.
if (!isInIframe()) initAnalytics();

Read-only preview

import { queryFlag } from 'ranuts';

openDocument(file, { readonly: queryFlag('readonly') });

Notes

1. A bare flag is the common spelling. ?embed carries no value, so getQuery(url).embed is '' — falsy — and a plain truthiness check silently misses the most common form. That is what queryFlag exists for.

2. ?k=false is false. An explicit negative is honoured rather than treated as "present, therefore on".

3. isInIframe is guarded. Reading window.parent can throw across origins in some engines; an unreadable parent is treated as embedded, because that is what it means.

4. Both are SSR-safe. With no window, isInIframe is false and queryFlag is false unless a url is passed — so both work in build-time scripts by supplying the URL.