JAVASCRIPT

check if the document is ready js

if (document.readyState === 'complete') {
  // The page is fully loaded
}

check if document is ready js

if( document.readyState !== 'loading' ) {
    console.log( 'document is already ready, just execute code here' );
    myInitCode();
} else {
    document.addEventListener('DOMContentLoaded', function () {
        console.log( 'document was not ready, place code here' );
        myInitCode();
    });
}

function myInitCode() {}

check if the document is ready js

let stateCheck = setInterval(() => {
  if (document.readyState === 'complete') {
    clearInterval(stateCheck);
    // document ready
  }
}, 100);