Expa

Firebase Realtime Database

Firebase API

{GET} - Get items

# Get whole collection
https://[database-name].firebaseio.com/[collection-name].json

# Get by key
https://[database-name].firebaseio.com/[collection-name]/[key].json

# Get by key and field in it
https://[database-name].firebaseio.com/[collection-name]/[key]/[field].json

{POST} - Create item

# Post some data 
https://[database-name].firebaseio.com/[collection-name].json

{DELETE} - Delete item

# Post some data 
https://[database-name].firebaseio.com/[collection-name]/[key].json

{PUT} - Update item

# Post data for update item
https://[database-name].firebaseio.com/[collection-name]/[key].json

# Post data for update item's field
https://[database-name].firebaseio.com/[collection-name]/[key]/[field].json

Firebase-API class

function FirebaseCRUD (table) {
  this.table = table || ''
  this.FIREBASE_API = function(id) {
   return https://zorg-007.firebaseio.com/${id ? this.table + '/' + id : this.table}.json
  }
}

FirebaseCRUD.prototype.request = function(url, method, data) {
 let options = {
    method: method || 'GET', // *GET, POST, PUT, DELETE, etc.
    body: data ? JSON.stringify(data) : null,
  headers: {
        'Content-Type': 'application/json',
        // 'Content-Type': 'application/x-www-form-urlencoded',
    },
 } 
 return fetch(url, options)
  .then((response) => response.json())
  // alert(response.headers.get('Content-Type')) // application/json charset=utf-8
    // alert(response.status) // 200
  .catch(alert)
}

FirebaseCRUD.prototype.get = function(id = null) {
  let url = this.FIREBASE_API(id)
  return this.request(url)
}

FirebaseCRUD.prototype.create = function(data) {
  let url = this.FIREBASE_API()
    // let data = {name: 'Fedor', surname: 'Alik'}
  return this.request(url, 'POST', data)
}

FirebaseCRUD.prototype.update = function(id, data) {
  let url  = this.FIREBASE_API(id)
  return this.request(url, 'PUT', data)
}

FirebaseCRUD.prototype.delete = function(id) {
  let url  = this.FIREBASE_API(id)
  return this.request(url, 'DELETE')
}

Firebase-SDK class


/**
  * Connect to a firebase realtime database and get connection 
  * @return {Object} database connection
  */
 module.exports.getDB = function () {
  const admin          = require('firebase-admin');
  const serviceAccount = require('./path/to/key.json')
  
  admin.initializeApp({
    credential: admin.credential.cert(serviceAccount),
    databaseURL: "https://__________.firebaseio.com"
  })
  
  return admin.database()
}



/**
 * FirebaseEntity - class for firebase realtime DB,
 * that have CRUD functions that allow to work with some nested object in realtime db 
 */

// constructor
function FirebaseEntity (table = '', db) {
  this.table    = table
  this.tableRef = db.ref(table)
}

/**
 * Add item in some nested item
 * @param {Object} data
 * @return {Promise} 
 */
FirebaseEntity.prototype.getItems = function () {
  let tableRef = this.tableRef
  return new Promise((res, rej) => {
    tableRef
    .on('value',
     (snapshot)    => res(snapshot.val()), 
     (errorObject) => console.log("The read failed: " + errorObject.code)
    )
  })
  .then((data) => {
    // Firebase возвращает записи в виде обьекта, где id это ключ, 
    // надо вынять ключи и поставить их как id,
    return Object.keys(data).map((key, index) => ({ id: key, ...data[key] })) 
  })
}

/**
 * Add item in some nested item(table)
 * @param {Object} data
 * @return {String} 
 */
FirebaseEntity.prototype.addItem = function (data) {
  let itemRef = this.tableRef.push(data)
  return itemRef.key
}

/**
 * Remove item by id
 * @param {String} id
 */
FirebaseEntity.prototype.deleteItem = function (id) {
  this.tableRef.child(id).remove()
}

/**
 * Update item by id
 * @param {String} id
 * @param {Object} data
 */
FirebaseEntity.prototype.updateItem = function (id, data) {
  if (!id) {
    console.log('No id provided')
    return
  }
  
  this.tableRef.update({
    [id]: data
  })

}

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