ArkTS Development

Build HarmonyOS applications using ArkTS and the ArkUI declarative UI framework.

Quick Start

Create a basic component:

@Entry
@Component
struct HelloWorld {
  @State message: string = 'Hello, ArkTS!';

  build() {
    Column() {
      Text(this.message)
        .fontSize(30)
        .fontWeight(FontWeight.Bold)
      Button('Click Me')
        .onClick(() => { this.message = 'Button Clicked!'; })
    }
    .width('100%')
    .height('100%')
    .justifyContent(FlexAlign.Center)
  }
}

State Management Decorators

V1 (Traditional)

Decorator	Usage	Description
@State	@State count: number = 0	Component internal state
@Prop	@Prop title: string	Parent → Child (one-way)
@Link	@Link value: number	Parent ↔ Child (two-way, use $varName)
@Provide/@Consume	Cross-level	Ancestor → Descendant
@Observed/@ObjectLink	Nested objects	Deep object observation

V2 (Recommended - API 12+)

Decorator	Usage	Description
@ComponentV2	@ComponentV2 struct MyComp	Enable V2 state management
@Local	@Local count: number = 0	Internal state (no external init)
@Param	@Param title: string = ""	Parent → Child (one-way, efficient)
@Event	@Event onChange: () => void	Child → Parent (callback)
@ObservedV2	@ObservedV2 class Data	Class observation
@Trace	@Trace name: string	Property-level tracking
@Computed	@Computed get value()	Cached computed properties
@Monitor	@Monitor('prop') onFn()	Watch changes with before/after
@Provider/@Consumer	Cross-level	Two-way sync across tree

See references/state-management-v2.md for complete V2 guide.

Common Layouts

// Vertical
Column({ space: 10 }) { Text('A'); Text('B'); }
  .alignItems(HorizontalAlign.Center)

// Horizontal
Row({ space: 10 }) { Text('A'); Text('B'); }
  .justifyContent(FlexAlign.SpaceBetween)

// Stack (overlay)
Stack({ alignContent: Alignment.Center }) {
  Image($r('app.media.bg'))
  Text('Overlay')
}

// List with ForEach
List({ space: 10 }) {
  ForEach(this.items, (item: string) => {
    ListItem() { Text(item) }
  }, (item: string) => item)
}

Component Lifecycle

@Entry
@Component
struct Page {
  aboutToAppear() { /* Init data */ }
  onPageShow() { /* Page visible */ }
  onPageHide() { /* Page hidden */ }
  aboutToDisappear() { /* Cleanup */ }
  build() { Column() { Text('Page') } }
}

Navigation

import { router } from '@kit.ArkUI';

// Push
router.pushUrl({ url: 'pages/Detail', params: { id: 123 } });

// Replace
router.replaceUrl({ url: 'pages/New' });

// Back
router.back();

// Get params
interface RouteParams {
  id: number;
  title?: string;
}
const params = router.getParams() as RouteParams;

Network Request

import { http } from '@kit.NetworkKit';

const req = http.createHttp();
const res = await req.request('https://api.example.com/data', {
  method: http.RequestMethod.GET,
  header: { 'Content-Type': 'application/json' }
});
if (res.responseCode === 200) {
  const data = JSON.parse(res.result as string);
}
req.destroy();

Local Storage

import { preferences } from '@kit.ArkData';

const prefs = await preferences.getPreferences(this.context, 'store');
await prefs.put('key', 'value');
await prefs.flush();
const val = await prefs.get('key', 'default');

ArkTS Language Constraints

ArkTS enforces stricter rules than TypeScript for performance and safety:

Prohibited	Use Instead
any, unknown	Explicit types, interfaces
var	let, const
Dynamic property access obj['key']	Fixed object structure
for...in, delete, with	for...of, array methods
#privateField	private keyword
Structural typing	Explicit implements/extends

See references/migration-guide.md for complete TypeScript → ArkTS migration details.

Command Line Test (hvigorw)

Build, clean, packaging, and device installation are covered by the harmonyos-build-deploy skill — use it for those workflows. The complete hvigorw flag reference is in references/hvigor-commandline.md.

Test commands:

# Run all tests for a module
hvigorw onDeviceTest -p module=entry -p coverage=true --no-daemon   # On-device
hvigorw test -p module=entry --no-daemon                            # Local (host-side)

# Run a single test suite or single test (on-device)
hvigorw onDeviceTest -p module=entry -p testParam="{\"unittest\":\"TestClassName\"}" --no-daemon
hvigorw onDeviceTest -p module=entry -p testParam="{\"unittest\":\"TestClassName#testMethodName\"}" --no-daemon

Code Linter (codelinter)

codelinter is the code checking and fixing tool for ArkTS/TS files.

# Basic usage
codelinter                           # Check current project
codelinter /path/to/project          # Check specified project
codelinter -c ./code-linter.json5    # Use custom rules

# Check and auto-fix
codelinter --fix
codelinter -c ./code-linter.json5 --fix

# Output formats
codelinter -f json -o ./report.json  # JSON report
codelinter -f html -o ./report.html  # HTML report

# Incremental check (Git changes only)
codelinter -i

# CI/CD with exit codes
codelinter --exit-on error,warn      # Non-zero exit on error/warn

Parameter	Description
-c, --config <file>	Specify rules config file
--fix	Auto-fix supported issues
-f, --format	Output format: default/json/xml/html
-o, --output <file>	Save result to file
-i, --incremental	Check only Git changed files
-p, --product <name>	Specify product
-e, --exit-on <levels>	Exit code levels: error,warn,suggestion

See references/codelinter.md for complete reference.

Stack Trace Parser (hstack)

hstack parses obfuscated crash stacks from Release builds back to source code locations.

# Parse crash files directory
hstack -i crashDir -o outputDir -s sourcemapDir -n nameCacheDir

# Parse with C++ symbols
hstack -i crashDir -o outputDir -s sourcemapDir --so soDir -n nameCacheDir

# Parse single crash stack
hstack -c "at func (entry|entry|1.0.0|src/main/ets/pages/Index.ts:58:58)" -s sourcemapDir

Parameter	Description
-i, --input	Crash files directory
-c, --crash	Single crash stack string
-o, --output	Output directory (or file with -c)
-s, --sourcemapDir	Sourcemap files directory
--so, --soDir	Shared object (.so) files directory
-n, --nameObfuscation	NameCache files directory

Requirements:

• Must provide either -i or -c (not both)
• Must provide at least -s or --so
• For method name restoration, provide both -s and -n

See references/hstack.md for complete reference.

Code Obfuscation (ArkGuard)

Enable in build-profile.json5:

"arkOptions": {
  "obfuscation": {
    "ruleOptions": {
      "enable": true,
      "files": ["./obfuscation-rules.txt"]
    }
  }
}

Common rules in obfuscation-rules.txt:

-enable-property-obfuscation      # Property name obfuscation
-enable-toplevel-obfuscation      # Top-level scope obfuscation
-enable-filename-obfuscation      # Filename obfuscation
-keep-property-name apiKey        # Whitelist specific names

See references/arkguard-obfuscation.md for complete guide.

Reference Files

• State Management V2: references/state-management-v2.md - Complete guide to V2 state management (@ComponentV2, @Local, @Param, @Event, @ObservedV2, @Trace, @Computed, @Monitor, @Provider, @Consumer)
• V1 to V2 Migration: references/state-management-v2-migration.md - Step-by-step migration from V1 to V2 decorators
• V2 Best Practices: references/state-management-v2-practices.md - V2 best practices and troubleshooting
• Migration Guide: references/migration-guide.md - Complete TypeScript to ArkTS migration rules and examples
• Component Patterns: references/component-patterns.md - Advanced component patterns and best practices
• API Reference: references/api-reference.md - Common HarmonyOS APIs
• ArkGuard Obfuscation: references/arkguard-obfuscation.md - Code obfuscation configuration and troubleshooting
• Hvigor Command Line: references/hvigor-commandline.md - Complete hvigorw build tool reference
• CodeLinter: references/codelinter.md - Code checking and fixing tool
• Hstack: references/hstack.md - Crash stack trace parser for Release builds

Development Environment

• IDE: DevEco Studio
• SDK: HarmonyOS SDK
• Simulator: Built-in DevEco Studio emulator

Related Skills

• Build & Deploy: See harmonyos-build-deploy skill for building, packaging, and device installation