operation.md

Operations

Check the specification to know more about the definition of Nimbus Operations.

Creating your own Operations

Nimbus already comes with some pre-defined operations, but for most applications, they're not enough and we need to extend them.

We'll use a function to format a value as a currency as an example.

1. Implement the operation

Write the structure with the parameters of the operation and make it conform to the protocol OperationDecodable.

import NimbusSwiftUI

struct FormatCurrency: OperationDecodable {
  static var properties = ["value", "currency"]
  
  var value: Double
  var currency: String
  
  func execute() -> String? {
    let formatter = NumberFormatter()
    formatter.numberStyle = .currency
    formatter.currencyCode = code
    return formatter.string(from: NSNumber(value: value))
  }
}

The OperationDecodable protocol is defined as follows:

public protocol OperationDecodable: Decodable {
  associatedtype Return
  func execute() -> Return
  
  static var properties: [String] { get }
}

• func execute() -> Return: A function that holds the implementation of the operation and returns a generic type Return.
• static var properties: [String]: An array with each element being the name of the struct's properties in the order they appear in the operation.

2. Register the operation

The same structure used for registering components and actions is used for registering operations: NimbusComposeUILibrary. See the example below:

let myAppUI = NimbusSwiftUILibrary("myApp")
  .addOperation("formatCurrency", FormatCurrency.self)

Whenever the operation "formatCurrency" is used by a server driven view, the function execute of FormatCurrency will be executed.

3. Certify your UI Library is registered to your Nimbus instance

import SwiftUI
import NimbusSwiftUI

struct ContentView: View {
  var body: some View {
    Nimbus(baseUrl: "my-base-url") {
      // Your navigator here
    }
    .ui([layout, myAppUI])
  }
}

Read next

👉 If you want to learn more about the Decodable usage in NimbusSwiftUI: Decodable. :point_right: Otherwise: Actions