Provider

The Provider protocol creates a simple and predictable way for adding functionality and third party packages to your Vapor project.

Adding a Provider

Adding a provider to your application takes 2-3 steps.

Add Package

All of Vapor's providers end with the -provider syntax. You can see a list of available providers by searching on our GitHub.

To add the provider to your package, add it as a dependency in your Package.swift file.

let package = Package(
    name: "MyApp",
    dependencies: [
        .Package(url: "https://github.com/vapor/vapor.git", majorVersion: 1, minor: 0),
        .Package(url: "https://github.com/vapor/mysql-provider.git", majorVersion: 1, minor: 0)
    ]
)

It's important to vapor clean or vapor build --clean after adding new packages.

Import

Once the provider has been added, you can import it using import VaporFoo where Foo is the name of the provider.

Here is what importing the MySQL provider looks like:

import Vapor
import VaporMySQL

let drop = Droplet()

try drop.addProvider(VaporMySQL.Provider.self)

// ...

drop.run()

Every provider comes with a class named Provider. Append the Type of this class to your providers array in the Droplet's init method.

Config

Some drivers may require a configuration file. For example, VaporMySQL requires a Config/mysql.json file like the following:

{
    "host": "localhost",
    "user": "root",
    "password": "",
    "database": "vapor"
}

You will receive an error during the Droplet's initialization if a configuration file is required.

Advanced

You may choose to initialize the provider yourself.

import Vapor
import VaporMySQL

let drop = Droplet()

let mysql = try VaporMySQL.Provider(host: "localhost", user: "root", password: "", database: "vapor")
drop.addProvider(mysql)

...

drop.run()

Create a Provider

Creating a provider is easy, you just need to create a package with a class Provider that conforms to Vapor.Provider.

Example

Here is what a provider for an example Foo package would look like. All the provider does is take a message, then print the message when the Droplet starts.

import Vapor

public final class Provider: Vapor.Provider {
    public let message: String
    public let provided: Providable

    public convenience init(config: Config) throws {
        guard let message = config["foo", "message"].string else {
            throw SomeError
        }

        try self.init(message: message)
    }

    public init(message: String) throws {
        self.message = message
    }

    public func afterInit(_ drop: Droplet) {

    }

    public func beforeServe(_ drop: Droplet) {
        drop.console.info(message)
    }
}

This provider wil require a Config/foo.json file that looks like:

{
    "message": "The message to output"
}

The provider can also be initialized manually with the init(message: String) init.