如何在特定条件下触发通知？答案

【问题标题】：How to trigger notification on certain condition?如何在特定条件下触发通知？
【发布时间】：2020-07-27 05:18:54
【问题描述】：

我在 firebase-messaging 中使用以下云功能作为通知目的，以通知用户有关 firestore 文档更改的通知，该功能工作正常，但我希望仅在满足特定条件时才触发通知

exports.sendNotification2 = functions.firestore.document("users/{to_user_id}/notifications_received/{notification_id}").onWrite((change, context)=>{

      const to_user_id = context.params.to_user_id;
      const notification_id = context.params.notification_id;
      const to_token_id = context.params.to_token_id;



      return admin.firestore().collection('users').doc(to_user_id).collection('notifications_received').doc(notification_id).get().then(queryResult=>{

          const from_user_id = queryResult.data().from_user_id;
          const to_token_id = queryResult.data().to_token_id;
          const to_user_id = queryResult.data().to_user_id;
          const notificaionmessage = queryResult.data().notification_message;
         
          const notification_id = queryResult.data().notification_id;
          const value = queryResult.data().value;

          const payload = {

              notification : {
                  title: notificaionmessage,
                  body: notificaionmessage,
                  icon:"default"
                              },

                              data: {

                                       click_action: 'FLUTTER_NOTIFICATION_CLICK2',
                                       notification_id: notification_id,

                                       category: 'default'
                                     }
          };



         return admin.messaging().sendToDevice(to_token_id,payload).then(result=>{

              console.log("Notification Sent Successfulllllllllllll");
              return null;
          });

      }


      );

  });

我希望当 value 变量是一个数字，是 hundered 的倍数时，才应该触发通知。我知道value%100 == 0 的逻辑来检查数字是否是百的倍数，但是我不知道如何实现这个逻辑？请进一步指导我

【问题讨论】：

标签： javascript firebase google-cloud-firestore google-cloud-functions firebase-cloud-messaging

【解决方案1】：

希望这会有所帮助！只需将发送通知代码放在if 块中，然后在else 中返回null 或其他内容。

if (value%100 === 0){
const payload = {

              notification : {
                  title: notificaionmessage,
                  body: notificaionmessage,
                  icon:"default"
                              },

                              data: {

                                       click_action: 'FLUTTER_NOTIFICATION_CLICK2',
                                       notification_id: notification_id,

                                       category: 'default'
                                     }
          };



         return admin.messaging().sendToDevice(to_token_id,payload).then(result=>{

              console.log("Notification Sent Successfulllllllllllll");
              return null;
          });
}//end if block
else return null;

【讨论】：