这是我的数据库的结构
root
datizme
site10
site22
site35
下面的脚本允许我获得在我的对象datizme中进行的所有修改,但我只想获得添加或删除的文档或其中进行了修改的文档的密钥。我没有在范围内找到教程
( function() {
// Your web app's Firebase configuration
const config = {
apiKey: "AIzaSsfxIeIaC1bruN12g",
authDomain: "c-3d423.firebaseapp.com",
databaseURL: "https://c-3d423.firebaseio.com",
projectId: "c-3d423",
storageBucket: "c-3d423.appspot.com",
messagingSenderId: "745995",
appId: "1:74591495:web:edec51656db3df2"
};
// Initialize Firebase
firebase.initializeApp(config);
const preObject = document.getElementById("datizme");
var dbRefObject = firebase.database().ref('datizme');
dbRefObject.on('value', snap => {
preObject.innerText = JSON.stringify(snap.val(), null, 3);
});
}());
如果要检测datizme
的哪个子节点发生了更改,可以使用child_changed
事件:
dbRefObject.on('child_changed', snap => {
console.log(snap.key+" was changed, its new value is "+snap.val());
});
添加(child_added
(或删除(child_removed
(子项时也有类似的事件。