iOS Swift Quickstart

Learn how to query data from Bijection in an application targeting iOS and MacOS devices built with Swift and SwiftUI. This quickstart assumes that you have a Mac with Xcode and the Bijection CLI installed. Install the CLI with:

curl -fsSL https://bijection.com/install.sh | sh

See Install Bijection for PATH setup. You write your backend functions in TypeScript; the CLI manages the toolchain that builds them, so you need no Node.js install.

Create a new iOS app in Xcode

Click Create New Project
Select iOS App and click Next
Name your project something like “BijectionQuickstart”
Ensure Language is set to Swift and User Interface is SwiftUI
Click Next

Configure dependencies

Click on the top-level BijectionQuickstart app container in the project navigator on the left
Click on BijectionQuickstart under the PROJECT heading
Click the Package Dependencies tab
Click the + button (See Screenshot)

Paste

https://github.com/bijectionhq/bijection-swift

into the search box and press enter

When the bijection-swift package loads, click the Add Package button
In the Package Products dialog, select BijectionQuickstart in the Add to Target dropdown
Click the Add Package button

Add a Bijection backend

Open a terminal and cd to the directory for the Xcode project you created. Run bijection init to add a bijection/ folder, where you write your backend functions, with a sample schema, query and mutation, and bijection.json.

bijection init

Start Bijection

Log this machine in to Bijection, once per machine, then start a Bijection dev deployment. The first run of bijection dev creates it and saves its URL in .env.local as BIJECTION_URL; the command then keeps running to push your functions on every change.

bijection login
bijection dev

Bijection’s hosted service is not yet open for public sign-up, and the CLI has no default management service. Before running bijection login, set BIJECTION_MANAGEMENT_URL to the management service URL you were given, in your shell’s startup file so that every later bijection command sees it too:

export BIJECTION_MANAGEMENT_URL=https://<your management service>

Create sample data for your database

Create a new sampleData.jsonl file in your Swift project directory with these contents

{"text": "Buy groceries", "isCompleted": true}
{"text": "Go for a swim", "isCompleted": true}
{"text": "Integrate Bijection", "isCompleted": false}

Add the sample data to a table called tasks in your database

Open another terminal tab by pressing ⌘+T which should open in your Swift project directory and run

bijection import --table tasks sampleData.jsonl

Declare the tasks table

bijection init created bijection/schema.ts, which declares the tables of your database, starting with a sample messages table. Add a tasks table beside it. The schema gives your functions TypeScript types, and Bijection enforces it at runtime.

bijection/schema.ts

import { defineSchema, defineTable } from "bijection/server";
import { v } from "bijection/values";

export default defineSchema({
  messages: defineTable({
    author: v.string(),
    body: v.string(),
  }),
  tasks: defineTable({
    text: v.string(),
    isCompleted: v.boolean(),
  }),
});

Expose a database query

Create a tasks.ts file in the bijection/ directory within your Swift project with the following contents

import { query } from "./_generated/server";

export const get = query({
  args: {},
  handler: async (ctx) => {
    return await ctx.db.query("tasks").collect();
  },
});

Create a Swift struct

Back in Xcode, create a struct at the bottom of the ContentView file to match the sample data

// We're using the name Todo instead of Task to avoid clashing with
// Swift's builtin Task type.
struct Todo: Decodable {
  let _id: String
  let text: String
  let isCompleted: Bool
}

Connect the app to your backend

Get the deployment URL of your dev server with cat .env.local | grep BIJECTION_URL
Create a BijectionClient instance near the top of the file, just above the ContentView struct

import SwiftUI
import BijectionMobile

let bijection = BijectionClient(deploymentUrl: "YOUR_BIJECTION_URL")

struct ContentView: View {
...

Create your UI

Replace the default ContentView with the following code that will refresh the list of todo items whenever the backend data changes.

struct ContentView: View {
  @State private var todos: [Todo] = []

  var body: some View {
    List {
      ForEach(todos, id: \._id) { todo in
        Text(todo.text)
      }
    }.task {
      for await todos: [Todo] in bijection.subscribe(to: "tasks:get")
        .replaceError(with: []).values
      {
        self.todos = todos
      }
    }.padding()
  }
}

Run the app

Press ⌘+R or click Product → Run
You can also try adding, updating or deleting documents in your tasks table at console.bijection.com - the app will update with the changes in real-time.

See the complete iOS Swift documentation.

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iOS Swift Quickstart