Ferno allows you to easily connect your Vapor project with your Firebase realtime database. It is built with the brand new Vapor 4. It gives you a nice and clean interface to interact with the Firebase Realtime REST API. It will automatically turn the response into your class/struct!

You will need:

• Vapor 4.8+

In your Package.swift file, add the line

.package(url: "https://github.com/vapor-community/ferno.git", from: "0.6.0")

Also make sure you add Ferno as a dependency

dependencies: [
  .product(name: "Ferno", package: "ferno")
]

1. Ferno uses an access token to read and write to your database. First we will need to get your service account information.

   • Log into the Firebase console
   • Click the settings gear next to Project Overview
   • Select Project settings
   • Select the SERVICE ACCOUNTS tab
   • Click the button at the bottom that says GENERATE NEW PRIVATE KEY
   • This will download a .json file. You will now have access to the email and private key. You will pass those into the initialize during the next step.

2. Register Ferno as a Provider and import Ferno. This is usually done in configure.swift

1. Log into the Firebase console
2. Click the settings gear next to Project Overview
3. Select Project settings
4. Select the SERVICE ACCOUNTS tab
5. Select Firebase Admin SDK option
6. Click the button Generate new private key to download the json file.

You can use the content of json file information to fill out the FernoDefaultConfiguration or use the json file to preper the FernoServiceJsonConfiguration.

import Ferno

let fernoConfiguration = FernoDefaultConfiguration(
    basePath: "database-url", 
    email: "service-account-email", 
    privateKey: "private-key"
)
app.ferno.use(.default(fernoConfiguration))

If you prefer to use the Firebase ServiceAccount.json follow the example below.

import Ferno

// option 1
let fernoConfiguration = try FernoServiceJsonConfiguration(json: Data)

// option 2
let fernoConfiguration = try FernoServiceJsonConfiguration(path: URL)

// option 3
let fernoConfiguration = FernoServiceJsonConfiguration(
                type: String,
                projectId: String,
                privateKeyId: String,
                privateKey: String,
                clientEmail: String,
                clientId: String,
                authUri: String,
                tokenUri: String,
                authProviderX509CertUrl: String,
                clientX509CertUrl: String,
                universeDomain: String
)

app.ferno.use(.serviceAccountKey(fernoConfiguration))

There are some custom parameters to pass into functions. I want to go over all the parameters you will need to know.

In GET requests, you might want to query on your data. This is what [FernoQuery] is for.

FernoQuery is an enum with:

1. case shallow(Bool)
2. case orderBy(FernoValue)
3. case limitToFirst(FernoValue)
4. case limitToLast(FernoValue)
5. case startAt(FernoValue)
6. case endAt(FernoValue)
7. case equalTo(FernoValue)

These are all the possible queries that are allowed on Firebase according to the docs

• shallow(Bool) cannot be mixed with any other query parameters.
• you usually use orderBy(FernoValue) in conjunction with enums 3-7
• using orderBy(FernoValue) alone will just order the data returned

You will notice most cases in FernoQuery have a value of FernoValue. FernoValue is just a wrapper for Bool, String, Int, Double, Float. So you can just do .startAt(5) and everything will work.

Just using shallow:

[.shallow(true)]

Filter data to only return data that matches "age": 21:

[.orderBy("age"), .equalTo(21)]

Just orderBy(returns data in ascending order):

[.orderBy("age")]

There are 6 functions that allow you to interact with your Firebase realtime database.

There are four functions that allow you get your data.

app.ferno.retrieve(_ path: [String], queryItems: [FernoQuery] = [])

app.ferno.retrieve(_ path: String..., queryItems: [FernoQuery] = [])

app.ferno.retrieveMany(_ path: [String], queryItems: [FernoQuery] = [])

app.ferno.retrieveMany(_ path: String..., queryItems: [FernoQuery] = [])

The only difference between retrieve and retrieveMany is the return type.

• retrieve returns -> F where F is of type Decodable
• retrieveMany returns -> [String: F] where F is of type Decodable and String is the key

1. Define the value you want the data converted.

struct Developer: Content {
   var name: String
   var favLanguage: String
   var age: Int
}

2. Make the request. Make sure you set the type of the response so Ferno knows what to convert.

let developers: [String: Developer] = try await app.ferno.retrieveMany("developers")
let developer: Developer = try await app.ferno.retrieve(["developers", "dev1"])

Used to create a new entry in your database

app.ferno.create(_ path: [String], body: T) try await -> FernoChild

app.ferno.create(_ path: String..., body: T) try await -> FernoChild

• body: T is of type Content.
• FernoChild is a struct:

struct FernoChild: Content {
  var name: String
}

• FernoChild is returned, because the API request returns the key from the newly created child.

let newDeveloper = Developer(name: "Elon", favLanguage: "Python", age: 46) // conforms to Content
let newDeveloperKey: FernoChild = try await app.ferno.create("developers", body: newDeveloper)

Used to delete an entry in your database

app.ferno.delete(_ path: [String]) try await -> Bool

app.ferno.delete(_ path: String...) try await -> Bool

• the delete method will return a boolean depending on if the delete was successful

let successfulDelete: Bool = try await app.ferno.delete(["developers", "dev-1"])

Update values at a specific location, but omitted values won't get removed

app.ferno.update(_ path: [String], body: T) try await -> T

app.ferno.update(_ path: String..., body: T) try await -> T

• the update method will return the body

struct UpdateDeveloperName: Content {
  var name: String
}

let newDeveloperName = UpdateDeveloperName(name: "Kimbal") //conforms to Content
let updatedDeveloperName: UpdateDeveloperName = try await app.ferno.update(["developers", newDeveloperKey.name], body: newDeveloper) //newDeveloperKey.name comes from the create method

Overwrite the current location with data you are passing in

client.ferno.overwrite(_ path: [String], body: T) try await -> T

client.ferno.overwrite(_ path: String..., body: T) try await -> T

struct LeadDeveloper: Content {
  var name: String
  var company: String
  var age: Int
}

let leadDeveloper = LeadDeveloper(name: "Ashley", company: "Bio-Fit", age: 20)
let leadDevResponse: LeadDeveloper = try await app.ferno.overwrite(["developers", newDeveloperKey.name], body: leadDeveloper)

Currently, tests were written using an actual dummy Firebase realtime database. If you want to run all of the tests, you will need to create a dummy Firebase realtime database.

You need to go to Application+Testing.swift and fill in the missing values based on your Firebase service account. Then you will be able to run tests.

• Austin Astorga - Main developer
• Maxim Krouk - Migration to Vapor4
• Petr Pavlik - Migrated to async/await

This project is licensed under the MIT License - see the LICENSE.md file for details

• Vapor Discord (for helping me with all my issues <3)
• Stripe Provider as a great template! stripe-provider