how to use NodeJS pop up a alert window in browser

Question

I'm totally new to Javascript and I'm wondering how to use node js to pop up a alert window in browser, after sever(Nodejs) received post message from front end? Do I need to use Ajax?

Answer 1

"after sever(Nodejs) received post message from front end?" show a pop up in the browser. This can not be done. I assume you want to show a popup in if the post request is success. Because you mention about Ajax, This is how it is done.

in your post router definition in the server do it as follows

router.post('/path', function(req, res){
   //do something
   res.jsonp({success : true})
});

something like this. finally you want to send something form the server to the client. after in the client side javascript file send the post request as follows.

$.ajax({
    url:"/url/is/here",
    method: "POST",
    data : {
        data : "what you want to send",
        put : "them here"
    },
    cache : false,
    success : function (data) {
        // data is the object that you send form the server by 
        // res.jsonp();
        // here data = {success : true}
        // validate it
        if(data['success']){
            alert("message you want to show");
        }
    },
    error : function () {
        // some error handling part
        alert("Oops! Something went wrong.");
    }
});