MediaWiki:Gadget-HideFundraisingNotice.js

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if( typeof document.addEventListener != "undefined" ) {
 document.addEventListener("beforeload", blockBannerLoader, true);
}

function blockBannerLoader(e) {
 if (!e) var e = window.event;
 var el = e.target;
 if( !el ) return;
 var elType = el.nodeName.toUpperCase();

 if (elType && elType === 'SCRIPT' ) {
  var src = el.src;
  if( !src ) return;
  if( src.indexOf( "Special:BannerLoader" ) != -1 || src.indexOf( "Special:BannerListLoader" ) != -1 ) {
   e.preventDefault();
  }
 }
}