Chapter 2.4 - Accepting Donations

Chapter 2.4 - Accepting Donations

Even if this part might not be vital for our bot, it is always useful to have something very simple which will accept all donations for us. To do this first we will need to identify what a donation fundamentally is: a donation is when the user sends us items and we do not send any items back in the trade. Knowing this we can use our knowledge to implement this very simple concept.

Let's create a new file called project3.js and copy the code from Chapter 2.2. We'll recode the newOffer event listener so that it will accept incoming donations. Delete all the code within the newOffer event listener and we can get started.

manager.on('newOffer', offer => {
  if (offer.itemsToGive.length === 0) {
    offer.accept((err, status) => {
      if (err) {
        console.log(err);
      } else {
        console.log(`Donation accepted. Status: ${status}.`);
      }
    });
  } else {
    offer.decline(err => {
      if (err) {
        console.log(err);
      } else {
        console.log('Donation declined (wanted our items).');
      }
    });
  }
});

With these very simple lines we are first checking if the array which contains our items (offer.itemsToGive) contains 0 items. We are using .length to do this. This property will equal 0 only if offer.itemsToGive is empty or contains no elements. If we think about our previous definition of a donation then this will indeed mean that if this statement is true then the trade offer is a donation. If the donation is trying to take items from us, we'll decline that offer.

Run the file using node project3.js. Try sending the bot an offer where you are giving it items, and one where you are trying to take items. The first should be accepted, while the second should be declined.