YUI 3 'on'.js

var inputs = Y.all( 'input' );

inputs.on( 'focus', function ( e ) {
    // NodeList subscriptions use the NodeList as 'this'
    this === inputs; // true

    // because you can always get to the node from the event's currentTarget,
    // but can't get to the NodeList unless you've prefetched it like in this ex
    e.currentTarget.get( 'tagName' ) === 'INPUT'; // true
} );

// So here, for example, the NodeList is not stored, and so otherwise would be
// unavailable to the callback.
Y.all( 'input' ).on( 'focus', function ( e ) {
    ???.odd().addClass( 'stripe' );
} );

// Y.all( x ).on( y, fn ) is essentially equivalent to
// Y.all( x ).each( function ( item ) { item.on( y, fn, Y.all( x ) ); } );

// All that said, prefer event delegation for subscribing to multiple elements
// with the same handler.
Y.one( 'doc' ).delegate( 'focus', function ( e ) {
    // Context is corrected to the input
    this.get( 'nodeName' ) === 'INPUT'; // true

    // As is the event's currentTarget
    e.currentTarget.get( 'nodeName' ) === 'INPUT'; // true
} );

// Incidentally, focus and blur don't bubble in all browsers, but YUI 3 corrects
// that if you include the event-focus or event (rollup) module.
YUI().use( 'node', 'event', function ( Y ) { /* go crazy */ } );