按文档 ID 更新单个文档 - Firestore

Question

I'm trying to have a like and unlike feature, based on whether the status is "unliked" or "liked". When a liked product is clicked, the status should get updated. I cannot seem to figure out how to pass the current document's ID to.doc!

The starting state:

const [entities, setEntities] = useState([]);

This is my unlike function (the entity.id obviously gives me an error - undefined):

const unlikeProduct = async () => {

    firestore()
      .collection('likes')
      .doc(entity.id)
      .update({
        status: "unliked",
      })
      .then(() => {
          console.log("unliked");
        Alert.alert(
          'You have unliked this product!',
        );
      });
  };

The button that sends a call to the unlike function:

<View style={styles.addToCartBtn}>
              <Icon name="heart" size={15} color={colours.white} onPress={() => unlikeProduct()}/>
            </View>

This function displays all the products which have status "liked":

    firestore()
      .collection('likes')
      .where('status', '==', 'liked')
      .onSnapshot(
        (querySnapshot) => {
          const newEntities = [];
          querySnapshot.forEach((doc) => {
            const entity = doc.data();
            entity.id = doc.id;
            newEntities.push(entity);
          });
          setEntities(newEntities);
        },
        (error) => {
          console.log(error);
        },
      );
  }, []);

tldr; I just want to retrieve the document ID of the product I'm trying to unlike.

Answer 1

Assuming you are mapping over the entities for displaying the Views, you can access each entity's id and pass it to your unlikeProduct function. Something like this:

{entities.map((entity) => (
  <View style={styles.addToCartBtn}>
    <Icon name="heart" size={15} color={colours.white} onPress={() => unlikeProduct(entity.id)}/>
  </View>
))}

Then receive the entity.id in your unlikeProduct function as a parameter and it wont be undefined anymore. Like so:

const unlikeProduct = async (id) => {

firestore()
  .collection('likes')
  .doc(id)
  .update({
    status: "unliked",
  })
  .then(() => {
      console.log("unliked");
    Alert.alert(
      'You have unliked this product!',
    );
  });
};