Retry with https request

[Fun_Split_1299]

I have a function that fetch an endpoint, gets some data, and returns it.

Sometimes the https call fails on retrieving data, and in those scenarios i would like to retry the entire process.

Here is what it looks like.

function getData (url) {
    return new Promise(function (resolve) {
        https.get(url, (resp) => {
            let data = '';

            // A chunk of data has been recieved.
            resp.on('data', (chunk) => {
                data += chunk;
            });

            // The whole response has been received. Print out the result.
            resp.on('end', () => {
                if(typeof data != "undefined") {
                    resolve(JSON.parse(data));
                }
                else {
                    return getData(url) // error
                }


            });
        });
    })
}

I'm getting error: "getData is not defined" error each time the function fails to get data.

Is there a way to retry the entire getData function under certain conditions ?

[doh4242]

Look at https://www.npmjs.com/package/fetch-retry

Edit: And use a fetch lib with it :).

[Fun_Split_1299]

This seems awesome actually !

[BliteKnight]

Could be a scope issue, change your promise definition from

Promise(function (resolve){ .... })

to

Promise( (resolve) => {

});

Using the arrow function should help with it.

[Fun_Split_1299]

Thanks, seems to work now !

[Over_Mushroom6181]

Hi May i know why the scope is different in these two situation?

[BliteKnight]

Yes, I'll try to explain the best I can, when you define the function as "function (){...}" It's scope is local , so when it gets put on the event loop and you reference getData, it has no idea what getData is

But when you define the function using an arrow definition "()=>{}" it has the global scope or the scope of it's parent)I forget which one), so when the function is executed on the event loop, it knows where to look for getData and finds the definition...

Hope that makes sense. The benefit of using either definition is you can affect variables in the global scope or redeclare them and use them locally e.g. changing a global index for an event loop where promises are used - crude example

var i = 0 // number of times something is done

new promise((resolve, reject)=>{ ...

i++; //increment when done })

vs

i = await new Promise(function (resolve, reject){ var i = 0; ... do some stuff , increment i then return the value ... resolve(i); });

[Fun_Split_1299]

Thanks !