Pi's Blog

const Ref = firebase.database().ref()

const user = firebase.auth().currentUser
const userRef = firebase.database().ref('/users/'+ user.uid)

const userHobbyRef = userRef.child('hobby')

userRef.set({
	name:'Tony',
	age:24
	hobby:['tennis','coding','eating']
	timeStamp: Date.now()
})

const postListRef = firebase.database().ref('/posts/')

//保留 Ref 以便之後使用
const newPostRef = postListRef.push()
newPostRef.set('New Post')

// 直接寫入
postListRef.push('New Post')

const newPostKey = postListRef.push().key

// userRef.on(eventtype,callback(snap))

userRef.on('value', (snap)=>{
	setUserEmail(JSON.stringify(snap.child('user_email').val()))
})

userRef.get()
  .then()
  .catch()
// return a Promise (dataSnapshot or rejection)

var adaNameRef = firebase.database().ref('users/ada/name');
// Modify the 'first' and 'last' properties, but leave other data at
// adaNameRef unchanged.
adaNameRef.update({ first: 'Ada', last: 'Lovelace' });

var ref = firebase.database().ref()
// Generate a new push ID for the new post
var newPostRef = ref.child("posts").push();
var newPostKey = newPostRef.key();
// Create the data we want to update
var updatedUserData = {};
updatedUserData["user/posts/" + newPostKey] = true;
updatedUserData["posts/" + newPostKey] = {
  title: "New Post",
  content: "Here is my new post!"
};
// Do a deep-path update
ref.update(updatedUserData, function(error) {
  if (error) {
    console.log("Error updating data:", error);
  }
});

Ref.Remove()
// return a Promise

async function onLogIn() {
        try {
            await Facebook.initializeAsync({
                appId: YOUR_APP_ID,      // 換成你的AppId
            });

            //{type,token,expirationDate,permissions,declinedPermissions,}
            const result = await Facebook.logInWithReadPermissionsAsync({
                permissions: ['public_profile', 'email'],   // 還有其他 permission
            });
            if (result.type === 'success') {
                // 利用 FB 提供的圖形API fetch 用戶名
                const response = await fetch(`https://graph.facebook.com/me?access_token=${result.token}`);
		alert( await response.json().name)
		//setToken(result.token) 
		//在這把token存起來，有時會在onLogIn外面遇到

                console.log('Logged in!');
            } else {
                console.log('type = cancel')
            }
        } catch ({ message }) {
            alert(`Facebook Login Error: ${message}`);
        }
    }

function checkLoginState(response) {
        let unsubscribe = firebase.auth().onAuthStateChanged((firebaseUser) => {
            unsubscribe();
            if (!isUserEqual(response, firebaseUser)) {
                let credential = firebase.auth.FacebookAuthProvider.credential(
                    response.token);
                firebase.auth().signInWithCredential(credential)
                    .catch((error) => { });
            } else {
                console.log('User is already signed-in Firebase with the correct user.')
            }
        });
    }

function isUserEqual(facebookAuthResponse, firebaseUser) {
        if (firebaseUser) {
            var providerData = firebaseUser.providerData;
            for (var i = 0; i < providerData.length; i++) {
                if (providerData[i].providerId === firebase.auth.FacebookAuthProvider.PROVIDER_ID &&
                    providerData[i].uid === facebookAuthResponse.userID) {
                    // We don't need to re-auth the Firebase connection.
                    return true;
                }
            }
        }
        return false;
    }

import * as Google from 'expo-google-app-auth';

async function signInWithGoogleAsync() {
  try {
    const result = await Google.logInAsync({
      androidClientId: YOUR_CLIENT_ID_HERE, //在這裡貼上你的用戶端編號, 記得加引號
      // iosClientId: YOUR_CLIENT_ID_HERE,
      scopes: ['profile', 'email'],
    });

    if (result.type === 'success') {
      return result.accessToken;
    } else {
      return { cancelled: true };
    }
  } catch (e) {
    return { error: true };
  }
}

function onSignIn(googleUser) {
        var unsubscribe = firebase.auth().onAuthStateChanged((firebaseUser) => {
            unsubscribe();   
							// 似乎是listener的常用語法，藉由呼叫函式本身，讓後面的程式只運行一次就好
            if (!isUserEqual(googleUser, firebaseUser)) {
                var credential = firebase.auth.GoogleAuthProvider.credential(
                    googleUser.idToken,
                    googleUser.accessToken
                );

                firebase.auth().signInWithCredential(credential)
                    .catch((error) => { alert('onSignInCredential'+error) });
            } else {
                console.log('User already signed-in Firebase.');
            }
        });
    }

function isUserEqual(googleUser, firebaseUser) {
        if (firebaseUser) {
            var providerData = firebaseUser.providerData;
            for (var i = 0; i < providerData.length; i++) {
                if (providerData[i].providerId === firebase.auth.GoogleAuthProvider.PROVIDER_ID &&
                    providerData[i].uid === googleUser.user.id) {   
                    // We don't need to reauth the Firebase connection.
                    return true;
                }
            }
        }
        return false;
    }

async function signInWithGoogleAsync() {
        try {
            const result = await Google.logInAsync({
                androidClientId: '994735805040-7q2nlrcnma0mssgvs7fimrmdp6dvuaqk.apps.googleusercontent.com', //在這裡貼上你的用戶端編號
                // iosClientId: YOUR_CLIENT_ID_HERE,
                scopes: ['profile', 'email'],
            });

            if (result.type === 'success') {
                onSignIn(result)               // <---- HERE
                return result.accessToken;
            } else { return { cancelled: true } }
        } catch (e) { return { error: true } }
    }