trustieforge/public/javascripts/wechat/directives/input_auto.js

app.directive('inputAuto',function(){
    return{
        restrict: 'A',
        scope: {},
        link: function(scope, element){
            var copyContainer = element.parent().children().children().eq(0);
            var sendButton = element.next();
            element.on('input',function(){
                //console.log(sendButton);
                copyContainer.html(element[0].value);
                var textHeight = copyContainer[0].scrollHeight-10;
                element.css('height', textHeight + 'px');
            });
            sendButton.on('click',function(){
                element.css('height','18px');
            });
        }
    }
});