如何在Firebase Cloud功能中执行类似'child-added'事件的操作？

2 回答

• 0

  您将要使用 onCreate 用于新推送的对象而不是 onWrite ，这将触发创建，更新或删除的对象 .

  您可以通过用大括号括起来将路径组件指定为通配符;

  您需要在数据库引用中使用通配符路径，如下所示：

  exports.checkForNew = functions.database.ref('foo/{createdID}').onCreate((created_child, context) => {
  
  //context.params.createdID to reference the ID of the created object in the database under 'foo'
  //created_child.val() to reference any field values of the created objcet
  
  });
  

  回复于 2024-05-14T13:39:26+08:00
• 0

  你走在正确的轨道上，你甚至自己找到了the relevant documentation ...在那个页面上，看看最后一个例子，我已经采用了这个例子并对其进行了一些编辑，以使你更清楚：

  Notice this parameter?
                                                       This function will only fire on
                                                       the new data-node itself, not on
                                                       the parent node...
                                                                \/
                                                                \/
  exports.makeUppercase = functions.database.ref('/messages/{pushId}')
      .onCreate( (change, context) => {
  
        // Since the function will only fire on the newly created node itself
        // the data that is 'after' the event will be your new data.
        // You can access the new data by calling:
        change.after.val()
  
        // From here you can do whatever actions you want with that data. 
        // You can access the {pushId} parameter with:
        context.params.pushId
  
      });
  

  回复于 2024-05-14T13:39:26+08:00