Kraken Terminal

This is a kraken Terminal made with Tauri project template using Next.js, bootstrapped by combining create-next-app and create tauri-app.

This template uses yarn as the Node.js dependency manager.

Template Features

• TypeScript frontend using Next.js React framework
• TailwindCSS as a utility-first atomic CSS framework
  • The example page in this template app has been updated to use only TailwindCSS
  • While not included by default, consider using HeadlessUI components for completely unstyled and fully accessible UI components, which integrate nicely with TailwindCSS
• Opinionated formatting and linting already setup and enabled
  • ESLint + Prettier for frontend, clippy and rustfmt for Rust code
• GitHub Actions to check code formatting and linting for both TypeScript and Rust

Getting Started

Running development server and use Tauri window

To develop and run the frontend in a Tauri window:

yarn dev

This will load the Next.js frontend directly in a Tauri webview window, in addition to starting a development server on localhost:3000.

Building for release

To export the Next.js frontend via SSG and build the Tauri application for release:

yarn build

Please remember to change the bundle identifier in tauri.conf.json > tauri > bundle > identifier, as the default value will yield an error that prevents you from building the application for release.

Source structure

Next.js frontend source files are located in src/ and Tauri Rust application source files are located in src-tauri/. Please consult the Next.js and Tauri documentation respectively for questions pertaining to either technology.

Caveats

Static Site Generation / Pre-rendering

Next.js is a great React frontend framework which supports server-side rendering (SSR) as well as static site generation (SSG or pre-rendering). For the purposes of creating a Tauri frontend, only SSG can be used since SSR requires an active Node.js server.

Using Next.js and SSG helps to provide a quick and performant single-page-application (SPA) frontend experience. More information regarding this can be found here: https://nextjs.org/docs/basic-features/pages#pre-rendering

next/image

The next/image component is an enhancement over the regular <img> HTML element with additional optimizations built in. However, because we are not deploying the frontend onto Vercel directly, some optimizations must be disabled to properly build and export the frontend via SSG. As such, the unoptimized property is set to true for the next/image component in the next.config.js configuration. This will allow the image to be served as-is from source, without changes to its quality, size, or format.

error[E0554]: #![feature] may not be used on the stable release channel

If you are getting this issue when trying to run yarn tauri dev, it may be that you have a newer version of a Rust dependency that uses an unstable feature. yarn tauri build should still work for production builds, but to get the dev command working, either downgrade the dependency or use Rust nightly via rustup override set nightly.

ReferenceError: navigator is not defined

If you are using Tauri's invoke function or any OS related Tauri function from within JavaScript, you may encounter this error when importing the function in a global, non-browser context. This is due to the nature of Next.js' dev server effectively running a Node.js server for SSR and hot module replacement (HMR), and Node.js does not have a notion of window or navigator.

Solution 1 - Dependency Injection (may not always work)

Make sure that you are calling these functions within the browser context, e.g. within a React component inside a useEffect hook when the DOM actually exists by then. If you are trying to use a Tauri function in a generalized utility source file, a workaround is to use dependency injection for the function itself to delay the actual importing of the real function (see example below for more info).

Example using Tauri's invoke function:

src/lib/some_tauri_functions.ts (problematic)

// Generalized file containing all the invoke functions we need to fetch data from Rust
import { invoke } from "@tauri-apps/api/tauri"

const loadFoo = (): Promise<string> => {
  return invoke<string>("invoke_handler_foo")
}

const loadBar = (): Promise<string> => {
  return invoke<string>("invoke_handler_bar")
}

const loadBaz = (): Promise<string> => {
  return invoke<string>("invoke_handler_baz")
}

// and so on ...

src/lib/some_tauri_functions.ts (fixed)

// Generalized file containing all the invoke functions we need to fetch data from Rust
//
// We apply the idea of dependency injection to use a supplied invoke function as a
// function argument, rather than directly referencing the Tauri invoke function.
// Hence, don't import invoke globally in this file.
//
// import { invoke } from "@tauri-apps/api/tauri"  <-- remove this!
//

import { InvokeArgs } from "@tauri-apps/api/tauri"
type InvokeFunction = <T>(cmd: string, args?: InvokeArgs | undefined) => Promise<T>

const loadFoo = (invoke: InvokeFunction): Promise<string> => {
  return invoke<string>("invoke_handler_foo")
}

const loadBar = (invoke: InvokeFunction): Promise<string> => {
  return invoke<string>("invoke_handler_bar")
}

const loadBaz = (invoke: InvokeFunction): Promise<string> => {
  return invoke<string>("invoke_handler_baz")
}

// and so on ...

Then, when using loadFoo/loadBar/loadBaz within your React components, import the invoke function from @tauri-apps/api and pass invoke into the loadXXX function as the InvokeFunction argument. This should allow the actual Tauri API to be bundled only within the context of a React component, so it should not be loaded by Next.js upon initial startup until the browser has finished loading the page.

Solution 2: Wrap Tauri API behind dynamic import()

Since the Tauri API needs to read from the browser's window and navigator object, this data does not exist in a Node.js and hence SSR environment. One can create an exported function that wraps the Tauri API behind a dynamic runtime import() call.

Example: create a src/lib/tauri.ts to re-export invoke

import type { InvokeArgs } from "@tauri-apps/api/tauri"

const isNode = (): boolean =>
  Object.prototype.toString.call(typeof process !== "undefined" ? process : 0) ===
  "[object process]"

export async function invoke<T>(
  cmd: string,
  args?: InvokeArgs | undefined,
): Promise<T> {
  if (isNode()) {
    // This shouldn't ever happen when React fully loads
    return Promise.resolve(undefined as unknown as T)
  }
  const tauriAppsApi = await import("@tauri-apps/api")
  const tauriInvoke = tauriAppsApi.invoke
  return tauriInvoke(cmd, args)
}

Then, instead of importing import { invoke } from "@tauri-apps/api/tauri", use invoke from import { invoke } from "@/lib/tauri".

Learn More

To learn more about Next.js, take a look at the following resources:

• Next.js Documentation - learn about Next.js features and API.
• Learn Next.js - an interactive Next.js tutorial.

And to learn more about Tauri, take a look at the following resources:

• Tauri Documentation - Guides - learn about the Tauri toolkit.