A bidirectional input plugin as a Mithril component. With modulator: mod( bidi )( prop, dom ), where 'prop' is an m.prop containing the value, and dom is a compiled Mithril template describing the element. Demo here: http://jsfiddle.net/barney/g3zudyd3/

bidi.js

var bidi = {
    view : function( ctrl, prop, node ){
        var type = node.tag === 'select' 
            ? node.attrs.multi 
                ? 'multi' 
                : 'select' 
            : node.attrs.type;
 
        // Setup: bind listeners
        if( type === 'multi' ){
            node.attrs.onchange = function(){
                prop( [].slice.call( this.selectedOptions, function( x ){
                    return x.value;
                } ) );
            }
        }
        else if( type === 'select' ){
            node.attrs.onchange = function( e ){
                prop( this.selectedOptions[ 0 ].value );
            };
        }
        else if( type === 'checkbox' ){
            node.attrs.onchange = function( e ){
                prop( this.checked )
            };
        }
        else {
            node.attrs.onchange = node.attrs.oninput = function( e ){
                prop( this.value );
            }
        }

        if( node.tag === 'select' ){
            node.children.forEach( function( option ){
                if( option.attrs.value === prop() || option.children[ 0 ] === prop() ){
                    option.attrs.selected = true;
                }
            } );
        }
        else if( type === 'checkbox' ){
            node.attrs.checked = prop();
        }
        else if( type === 'radio' ){
            node.attrs.checked = prop() === node.attrs.value;
        }
        else {
            node.attrs.value   = prop();
        }

        return node;
    }
}

The demo gives a not found error