BestBuy API won't query in a loop-CodePudding

I am very new to Javascript and I am trying to utilize BestBuy's api to grab data on a specific sku number every 3 seconds.

The call to the api works as expected on its own but when I move the call inside a while loop, I do not get anything and the console.log in the function is not hit.

Not sure where to go from here and I am starting wonder if this api call can only be called by itself.

Would appreciate any help.

var bby = require('bestbuy')('<Actual BestBuy Api key in original code>');

var isSoldOut = true;

while(isSoldOut)
{
  console.log("HERE");
  bby.products(6465789,{show:'sku,name,salePrice,onlineAvailability,inStorePickup,onlineAvailabilityUpdateDate'}).then(function(data){
    console.log(data);

    if (data['onlineAvailability'] == false)
    {
    isSoldOut = false;
    console.log(isSoldOut);
    }
  });
  
  wait(3000);
}

function wait(ms)
{
    var d = new Date();
    var d2 = null;
    do { d2 = new Date(); }
    while(d2-d < ms);
}

CodePudding user response：

Your while loops are constantly blocking the thread, so your callback function can't run.

Instead of the while loops, you can use an interval:

var bby = require('bestbuy')('<Actual BestBuy Api key in original code>');

function check() {
  console.log("HERE");
  bby.products(6465789,{show:'sku,name,salePrice,onlineAvailability,inStorePickup,onlineAvailabilityUpdateDate'}).then(function(data){
    console.log(data);

    if (data['onlineAvailability'] == false)
    {
      clearInterval(loop);
      console.log("In Stock");
    }
  });
}

const loop = setInterval(check, 3000);

Even cleaner may be using async/await to wait 3 seconds after receiving each response:

var bby = require('bestbuy')('<Actual BestBuy Api key in original code>');

const wait = require('util').promisify(setTimeout);

async function check() {
  console.log("HERE");

  const data = await bby.products(6465789,{show:'sku,name,salePrice,onlineAvailability,inStorePickup,onlineAvailabilityUpdateDate'});
  console.log(data);

  if (data['onlineAvailability'] == false)
  {
    console.log("In Stock");
    return;
  }

  await wait(3000);
}

check();

CodePudding user response：

There are several points to improve your code:

Use setInterval to execute code in regular interval, instead of using spin lock in a while loop
Use async/await to improve readability
Instead of checking condition == false, simply check !condition
Instead of doing if(!condition){x = false}, simply do x = !condition
Use dot notation instead of bracket notation to access object property if the property name is not variable. This can take advantage of intellisense of IDE if the object shape is properly documented and reduce typo.

const t = setInterval(async () =>{
    const data = await bby.products(6465789, { show: 'sku,name,salePrice,onlineAvailability,inStorePickup,onlineAvailabilityUpdateDate' });
    console.log(data);
    isSoldOut = !data.onlineAvailability;
    console.log(isSoldOut);
    if(isSoldOut)
    {
        clearInterval(t);
    }
},3000);