IONIC + NODE.JS + MYSQL CORS issue for DEVAPP : Access-Control-Allow-Origin", "*"

Hello all,

I was facing CORS issue while running an API of NODE.JS with IONIC APP.
then I found solution i.e. plugin for chrome which worked for me only on chrome.
plugin was :

But then I faced same issue in Firefox also and I cam to this solution :

where I added

app.use(function (req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "Cache-Control, Pragma, Origin, Authorization, Content-Type, X-Requested-With");
    res.header("Access-Control-Allow-Methods", "GET, PUT, POST");
    if ('OPTIONS' === req.method) {
    else {

in my app.js file of node.

then its solved my issue for firefox.

**But now when I am running same on my DevApp its showing null that is full white blank screen which was show on both browsers before that solutions. Now I am unable to find solution for this.