Firebase Tips

fetchKeyOnly.js

var { google } = require("googleapis");
var request = require("request");

var serviceAccountDir = "./serviceAccountKey.json"

generateAccessToken(serviceAccountDir).then(access_token => {
    request({
        url: "https://database-cua-ban.firebaseio.com/path/nao/do.json",
        qs: {
            shallow: "true",
            access_token: access_token
        }
    }, (err, res, data) => {
        console.log(data)
    })
})

/** 
 * Tạo access_token từ serviceAccountKey.json
 * @param {String} dir     Đường dẫn đến file .json
 * @returns {Promise}      Resolve access_token
*/
function generateAccessToken(dir) {
    return new Promise(resolve => {
        // Load the service account key JSON file.
        var serviceAccount = require(dir);

        // Define the required scopes.
        var scopes = [
            "https://www.googleapis.com/auth/userinfo.email",
            "https://www.googleapis.com/auth/firebase.database"
        ];

        // Authenticate a JWT client with the service account.
        var jwtClient = new google.auth.JWT(
            serviceAccount.client_email,
            null,
            serviceAccount.private_key,
            scopes
        );
        
        // Use the JWT client to generate an access token.
        jwtClient.authorize(function(error, tokens) {
            if (error) {
                console.error("Error making request to generate access token:", error);
            } else if (tokens.access_token === null) {
                console.error("Provided service account does not have permission to generate access tokens");
            } else {
                resolve(tokens.access_token);
            }
        });
    })
}

generateSearchIndex.js

// For example:
// generateSearchIndex("Nguyen Xuan Son")
// returns ["Ngu", "Nguy", "Nguye", "Nguyen", "Xua", "Xuan", "Son"]

function generateSearchIndex(str) {
	var temp = []
	str.trim().split(" ").forEach(word => {
		temp = temp.concat(generateSearchIndexWord(word))
	})
	return temp
}

function generateSearchIndexWord(word) {
	if (word.length == 0) {
		return []
	} else if (word.length <= 3) {
		return [word]
	} else {
		var ret = []
		for (var i = 3 ; i <= word.length ; i++) {
			ret.push(word.substring(0, i))
		}
		return ret
	}
}

getOnlyGender.js

// Đây chỉ là code mẫu, mang tính tham khảo

var db = firebase.database()

// Danh sách id có thể lấy bằng cách dùng code từ mục 2
var ids = {
    "12417221992xxxxx": true,
    "16558810177xxxxx": true,
    "16030810531xxxxx": true,
    "22281263838xxxxx": true
}

var promises = Object.keys(ids).map(id => {
    return db.ref("/user/"+id+"/gender").once("value")
})

Promise.all(promises).then(snapshots => {
    var data = snapshots.map(snapshot => {
        return {
            id: snapshot.key,
            gender: snapshot.val()
        }
    })

    /*
        data giờ sẽ thành
        [
            { id: "12417221992xxxxx", gender: "female" },
            { id: "16558810177xxxxx", gender: "male" },
            { id: "16030810531xxxxx", gender: "female" },
            { id: "22281263838xxxxx", gender: "male" }
        ]
    */
})