v1/web/modules/contrib/advagg/advagg_mod/js/cssrelpreload.js

44 lines
1.3 KiB
JavaScript

/*! loadCSS rel=preload polyfill. [c]2017 Filament Group, Inc. MIT License */
(function( w ){
// rel=preload support test
if( !w.loadCSS ){
return;
}
var rp = loadCSS.relpreload = {};
rp.support = function(){
try {
return w.document.createElement( "link" ).relList.supports( "preload" );
} catch (e) {
return false;
}
};
// loop preload links and fetch using loadCSS
rp.poly = function(){
var links = w.document.getElementsByTagName( "link" );
for( var i = 0; i < links.length; i++ ){
var link = links[ i ];
if( link.rel === "preload" && link.getAttribute( "as" ) === "style" ){
w.loadCSS( link.href, link, link.getAttribute( "media" ) );
link.rel = null;
}
}
};
// if link[rel=preload] is not supported, we must fetch the CSS manually using loadCSS
if( !rp.support() ){
rp.poly();
var run = w.setInterval( rp.poly, 300 );
if( w.addEventListener ){
w.addEventListener( "load", function(){
rp.poly();
w.clearInterval( run );
} );
}
if( w.attachEvent ){
w.attachEvent( "onload", function(){
w.clearInterval( run );
} )
}
}
}( this ));