### Application Start Script Example

Source: https://developer.fnnas.com/docs/core-concepts/environment-variables

This script demonstrates how to use various environment variables to manage application startup, configuration, and status checks. It handles start, status, and stop commands.

```bash
#!/bin/bash  
  
case $1 in  
start)  
    echo "启动应用: $TRIM_APPNAME 版本: $TRIM_APPVER"  
    echo "应用目录: $TRIM_APPDEST"  
    echo "配置文件目录: $TRIM_PKGETC"  
    echo "数据目录: $TRIM_PKGVAR"  
    echo "服务端口: $TRIM_SERVICE_PORT"  
      
    # 检查配置文件是否存在  
    if [ ! -f "$TRIM_PKGETC/config.conf" ]; then  
        echo "配置文件不存在，创建默认配置..."  
        cp "$TRIM_APPDEST/config.conf.example" "$TRIM_PKGETC/config.conf"  
    fi  
      
    # 启动应用  
    cd "$TRIM_APPDEST"  
    ./myapp --config "$TRIM_PKGETC/config.conf" \  
            --data "$TRIM_PKGVAR" \  
            --port "$TRIM_SERVICE_PORT" \  
            --user "$TRIM_USERNAME" \  
            --log "$TRIM_TEMP_LOGFILE" &  
      
    echo "应用启动完成"  
    exit 0  
    ;;  
      
status)  
    # 检查应用是否在运行  
    if pgrep -f "myapp.*$TRIM_SERVICE_PORT" > /dev/null; then  
        echo "应用正在运行"  
        exit 0  
    else  
        echo "应用未运行"  
        exit 3  
    fi  
    ;;  
      
stop)  
    echo "停止应用..."  
    pkill -f "myapp.*$TRIM_SERVICE_PORT"  
    exit 0  
    ;;  
      
*)  
    echo "未知命令: $1"  
    exit 1  
    ;;  
esac  

```

--------------------------------

### Simulate Custom Exception in Start Script

Source: https://developer.fnnas.com/docs/core-concepts/framework

This example shows how to handle a missing configuration file during application startup. It writes an error to TRIM_TEMP_LOGFILE and exits with code 1.

```bash
#!/bin/bash  
  
case $1 in  
start)  
    # 检查配置文件是否存在  
    if [ ! -f "$TRIM_PKGETC/config.conf" ]; then  
        echo "配置文件不存在, 应用启动失败！" > "${TRIM_TEMP_LOGFILE}"  
        exit 1  
    fi  
      
    # 启动应用  
    cd "$TRIM_APPDEST"  
    ./myapp --config "$TRIM_PKGETC/config.conf" \  
            --data "$TRIM_PKGVAR" \  
            --port "$TRIM_SERVICE_PORT" \  
            --user "$TRIM_USERNAME" \  
            --log "$TRIM_TEMP_LOGFILE" &  
      
    echo "应用启动完成"  
    exit 0  
    ;;  
stop)  
    echo "停止应用..."  
    pkill -f "myapp.*$TRIM_SERVICE_PORT"  
    exit 0  
    ;;  
status)  
    # 检查应用是否在运行  
    if pgrep -f "myapp.*$TRIM_SERVICE_PORT" > /dev/null; then  
        echo "应用正在运行"  
        exit 0  
    else  
        echo "应用未运行"  
        exit 3  
    fi  
    ;;  
*)  
    exit 1  
    ;;  
esac  
```

--------------------------------

### Installation Wizard Configuration

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Defines the steps and fields for an installation wizard, including welcome messages, terms agreement, admin account creation, and application configuration like database type and port.

```json
[
    {
        "stepTitle": "欢迎安装",
        "items": [
            {
                "type": "tips",
                "helpText": "欢迎使用我们的应用！在开始使用前，请阅读并同意我们的服务条款。"
            },
            {
                "type": "tips",
                "helpText": "请阅读 <a target="_blank" href="https://example.com/privacy">隐私政策</a> 和 <a target="_blank" href="https://example.com/terms">服务条款</a>。"
            },
            {
                "type": "switch",
                "field": "wizard_agree_terms",
                "label": "我已阅读并同意服务条款",
                "rules": [
                    {
                        "required": true,
                        "message": "请同意服务条款"
                    }
                ]
            }
        ]
    },
    {
        "stepTitle": "创建管理员账号",
        "items": [
            {
                "type": "text",
                "field": "wizard_admin_username",
                "label": "管理员用户名",
                "initValue": "admin",
                "rules": [
                    {
                        "required": true,
                        "message": "请输入管理员用户名"
                    },
                    {
                        "pattern": "^[a-zA-Z0-9_]+$",
                        "message": "用户名只能包含字母、数字和下划线"
                    }
                ]
            },
            {
                "type": "password",
                "field": "wizard_admin_password",
                "label": "管理员密码",
                "rules": [
                    {
                        "required": true,
                        "message": "请输入管理员密码"
                    },
                    {
                        "min": 8,
                        "message": "密码长度不能少于8位"
                    }
                ]
            },
            {
                "type": "password",
                "field": "wizard_admin_password_confirm",
                "label": "确认密码",
                "rules": [
                    {
                        "required": true,
                        "message": "请确认密码"
                    }
                ]
            }
        ]
    },
    {
        "stepTitle": "应用配置",
        "items": [
            {
                "type": "select",
                "field": "wizard_database_type",
                "label": "数据库类型",
                "initValue": "sqlite",
                "options": [
                    {
                        "label": "SQLite (推荐，无需额外配置)",
                        "value": "sqlite"
                    },
                    {
                        "label": "MySQL",
                        "value": "mysql"
                    }
                ]
            },
            {
                "type": "text",
                "field": "wizard_app_port",
                "label": "应用端口",
                "initValue": "8080",
                "rules": [
                    {
                        "required": true,
                        "message": "请输入端口号"
                    },
                    {
                        "pattern": "^[0-9]+$",
                        "message": "端口号必须是数字"
                    }
                ]
            }
        ]
    }
]  
```

--------------------------------

### Example Manifest File

Source: https://developer.fnnas.com/docs/core-concepts/manifest

This example demonstrates a typical manifest file structure, including essential fields for application identification, system requirements, developer information, UI configuration, port settings, and dependency management.

```properties
appname=myapp
version=1.0.0
display_name=我的应用
desc=这是一个示例应用，展示了 manifest 文件的基本用法
arch=x86_64
source=thirdparty

maintainer=张三
maintainer_url=https://example.com
distributor=示例公司
distributor_url=https://company.com

os_min_version=0.9.0

desktop_uidir=ui
desktop_applaunchname=myapp.APPLICATION

service_port=8080
checkport=true

install_dep_apps=mariaDB:redis
```

--------------------------------

### Docker Compose File Example

Source: https://developer.fnnas.com/docs/core-concepts/resource

An example Docker Compose file defining services, ports, volumes, environment variables, and dependencies for a multi-container application.

```yaml
version: '3.8'

services:
  web:
    build: .
    ports:
      - "8080:80"
    volumes:
      - ./data:/app/data
    environment:
      - DB_HOST=db
      - DB_PORT=3306
    depends_on:
      - db

  db:
    image: mysql:8.0
    environment:
      - MYSQL_ROOT_PASSWORD=password
      - MYSQL_DATABASE=myapp
    volumes:
      - db_data:/var/lib/mysql

volumes:
  db_data:

```

--------------------------------

### Python MinIO Client Initialization and Bucket Creation

Source: https://developer.fnnas.com/docs/core-concepts/middleware

Initialize the MinIO client with your endpoint, access key, and secret key. This example demonstrates how to check for and create a bucket if it doesn't exist.

```python
import minio  
from minio import Minio  
from minio.error import S3Error  
  
# 1. 初始化客户端  
# 默认配置下的 MinIO 可通过 host 127.0.0.1 和 port 9000 连接  
client = Minio(  
    endpoint="127.0.0.1:9000",  
    access_key="your_access_key",   # 替换为你的 MinIO 管理员用户名 或 Access Key   
    secret_key="your_secret_key",   # 替换为你的 MinIO 管理员密码 或 Secret Key   
    secure=False                    # 本地测试通常为 False  
)  
  
# 2. 定义桶名  
bucket_name = "my-bucket"  
  
# 创建 Bucket 示例  
def main():  
    try:  
        # 检查桶是否存在，如果不存在则创建它  
        if not client.bucket_exists(bucket_name):  
            client.make_bucket(bucket_name)  
            print(f"Bucket '{bucket_name}' 已创建.")  
        else:  
            print(f"Bucket '{bucket_name}' 已存在.")  
    except S3Error as err:  
        print("创建 Bucket 时发生错误:", err)  
  
if __name__ == "__main__":  
    main()  

```

--------------------------------

### Correct Dependency Order for Installation

Source: https://developer.fnnas.com/docs/core-concepts/dependency

When declaring multiple dependencies, the order in `install_dep_apps` specifies the installation sequence. The system installs dependencies from right to left, ensuring that prerequisites are met before dependent applications are installed.

```properties
# 正确的依赖顺序，安装时将先安装dep1，后安装dep2  
install_dep_apps=dep2:dep1  

```

--------------------------------

### Incorrect Dependency Order Example

Source: https://developer.fnnas.com/docs/core-concepts/dependency

An incorrect dependency order in `install_dep_apps` can lead to installation failures or runtime issues if a dependent application is installed before its prerequisites. Always ensure the order reflects the actual dependency graph.

```properties
# 错误的依赖顺序，如果dep2依赖于dep1，可能导致问题  
install_dep_apps=dep1:dep2  

```

--------------------------------

### Application Directory Structure

Source: https://developer.fnnas.com/docs/core-concepts/framework

This outlines the standard directory structure for applications installed on the飞牛 fnOS system. It details system-created directories and developer-defined directories.

```bash
```
/var/apps/[appname]  
├── cmd  
│   ├── install_callback  
│   ├── install_init  
│   ├── main  
│   ├── uninstall_callback  
│   ├── uninstall_init  
│   ├── upgrade_init  
│   ├── upgrade_callback  
│   ├── config_init  
│   └── config_callback  
├── config  
│   ├──privilege  
│   └──resource  
├── ICON_256.PNG  
├── ICON.PNG  
├── LICENSE  
├── manifest  
├── etc->/vol[volume_number]/@appconf/[appname]  
├── home->/vol[volume_number]/@apphome/[appname]  
├── target->/vol[volume_number]/@appcenter/[appname]  
├── tmp->/vol[volume_number]/@apptemp/[appname]  
├── var->/vol[volume_number]/@appdata/[appname]  
├── shares  
│   ├──datashare1->/vol[volume_number]/@appshare/datashare1  
│   └──datashare2->/vol[volume_number]/@appshare/datashare2  
└── wizard  
    ├── install  
    ├── uninstall  
    ├── upgrade  
    └── config  

```
```

--------------------------------

### Configure Python Environment and Virtual Environment

Source: https://developer.fnnas.com/docs/core-concepts/runtime

Configure the PATH to include the Python 3.12 bin directory. Then, create and activate a virtual environment for project dependencies using venv and install requirements.

```bash
# Optional versions: python312, python311, python310, python39, python38
export PATH=/var/apps/python312/target/bin:$PATH

# Create virtual environment
python3 -m venv .venv

# Activate virtual environment
source .venv/bin/activate

# Install python related dependencies to .venv
pip install -r requirements.txt
```

--------------------------------

### Declare MinIO Dependency in Manifest

Source: https://developer.fnnas.com/docs/core-concepts/middleware

Add 'minio' to `install_dep_apps` in your manifest to ensure MinIO is running when your application starts.

```yaml
install_dep_apps=minio  
```

--------------------------------

### Application Lifecycle Management Script

Source: https://developer.fnnas.com/docs/core-concepts/framework

A basic structure for the main script that manages application start, stop, and status checks. It uses a case statement to handle different commands.

```bash
#!/bin/bash  
  
case $1 in  
start)  
    # 启动应用的命令，成功返回 0，失败返回 1  
    exit 0  
    ;;  
stop)  
    # 停止应用的命令，成功返回 0，失败返回 1  
    exit 0  
    ;;  
status)  
    # 检查应用运行状态，运行中返回 0，未运行返回 3  
    exit 0  
    ;;  
*)  
    exit 1  
    ;;  
esac  
```

--------------------------------

### Radio Button Group Configuration

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Set up radio buttons for single selection from a list of options, such as installation types. Requires a selection to be made.

```json
{
    "type": "radio",
    "field": "wizard_install_type",
    "label": "安装类型",
    "initValue": "standard",
    "options": [
        {
            "label": "标准安装",
            "value": "standard"
        },
        {
            "label": "自定义安装",
            "value": "custom"
        }
    ],
    "rules": [
        {
            "required": true,
            "message": "请选择安装类型"
        }
    ]
}
```

--------------------------------

### Declare Redis Dependency in Manifest

Source: https://developer.fnnas.com/docs/core-concepts/middleware

Add 'redis' to `install_dep_apps` in your manifest to ensure Redis is running when your application starts.

```yaml
install_dep_apps=redis  
```

--------------------------------

### Declare App Dependencies in Manifest

Source: https://developer.fnnas.com/docs/core-concepts/dependency

Use the `install_dep_apps` field in the `manifest` file to declare applications that must be installed and running for your application to function correctly. Dependencies are listed in order of execution, from last to first.

```properties
version=1.0.0  
install_dep_apps=dep2:dep1  

```

--------------------------------

### Declare Node.js v22 Dependency

Source: https://developer.fnnas.com/docs/core-concepts/runtime

Declare a dependency on Node.js v22 in the manifest file. The application center ensures this version is installed and available.

```yaml
install_dep_apps=nodejs_v22
```

--------------------------------

### Python Redis Connection and Usage Example

Source: https://developer.fnnas.com/docs/core-concepts/middleware

Connect to Redis using a connection pool, specifying the database and other parameters. The connection pool manages connections, so explicit closing is not required.

```python
import redis  

def main():  
    # 创建连接池，指定逻辑数据库（如 db=1），防止冲突  
    # 默认配置下的 redis 可通过 host 127.0.0.1 和 port 6739 连接  
    pool = redis.ConnectionPool(host='127.0.0.1', port=6379, db=1, decode_responses=True, max_connections=10)  

    # 从连接池获取连接  
    client = redis.Redis(connection_pool=pool)  

    # 使用连接  
    client.lpush('my_list', 'item1', 'item2')  
    items = client.lrange('my_list', 0, -1)  
    print(items)  # 输出: ['item2', 'item1']  

    # 不需要手动关闭连接，连接池会管理  
    # 但在程序退出前，可以关闭连接池  
    # pool.disconnect()  
    # 如需切换数据库，可重新创建连接池并指定不同的 db 参数  
  
if __name__ == "__main__":  
    main()  

```

--------------------------------

### Declare Python 3.12 Dependency

Source: https://developer.fnnas.com/docs/core-concepts/runtime

Declare a dependency on Python 3.12 in the manifest file. The application center ensures this version is installed and available.

```yaml
install_dep_apps=python312
```

--------------------------------

### Checkbox Group Configuration

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Define a checkbox group for multiple selections, like choosing installation modules. Users must select at least one option.

```json
{
    "type": "checkbox",
    "field": "wizard_modules",
    "label": "安装模块",
    "initValue": ["web", "api"],
    "options": [
        {
            "label": "Web界面",
            "value": "web"
        },
        {
            "label": "API接口",
            "value": "api"
        },
        {
            "label": "数据库",
            "value": "database"
        }
    ],
    "rules": [
        {
            "required": true,
            "message": "请至少选择一个模块"
        }
    ]
}
```

--------------------------------

### Declare Java 21 OpenJDK Dependency

Source: https://developer.fnnas.com/docs/core-concepts/runtime

Declare a dependency on Java 21 OpenJDK in the manifest file. The application center ensures this version is installed and available.

```yaml
install_dep_apps=java-21-openjdk
```

--------------------------------

### 打包应用

Source: https://developer.fnnas.com/docs/core-concepts/docker

在项目根目录执行 `fnpack build` 命令来打包应用，生成 `.fpk` 文件。

```bash
fnpack build
```

--------------------------------

### 创建 Docker 应用目录

Source: https://developer.fnnas.com/docs/core-concepts/docker

使用 `fnpack create` 命令创建应用目录，并指定 `docker` 模板。生成的目录结构包含应用代码、Docker 资源、配置文件和生命周期管理脚本。

```bash
fnpack create my-app -t docker
```

--------------------------------

### HTML Structure for App Center Demo

Source: https://developer.fnnas.com/docs/quick-started/create-application

Sets up the basic HTML for the App Center tutorial, including meta tags, title, CSS, and JavaScript imports.

```html
<!DOCTYPE html>  
<!-- 声明文档类型为 HTML5 -->  
<html lang="zh-CN">  
<head>  
    <!-- 字符编码：确保中文/特殊字符正常显示 -->  
    <meta charset="UTF-8">  
    <!-- 视口设置：适配移动端 -->  
    <meta name="viewport" content="width=device-width, initial-scale=1.0">  
    <!-- 页面标题：浏览器标签显示 -->  
    <title>应用中心教学演示</title>  
      
    <!-- 引入外部 CSS 样式文件（核心知识点：外部样式引入） -->  
    <!-- 路径说明：./ 表示当前目录，css/style.css 是样式文件的相对路径 -->  
    <link rel="stylesheet" href="./css/style.css">  
</head>  
<body>  
    <!-- 1. Logo 展示区（核心知识点：图片引入） -->  
    <div class="logo-container">  
        <!-- src：图片路径；alt：图片加载失败时的替代文本（无障碍/SEO） -->  
        <img src="./images/logo.png" alt="教学演示Logo" class="logo">  
    </div>  
  
    <div class="hello-container">  
        <h1 id="helloText">Welcome to the fnOS AppCenter</h1>  
        <p class="tips">点击上方文字体验JS交互</p>  
    </div>  
  
    <!-- 2. 引入外部 JS 文件（核心知识点：JS 文件引入） -->  
    <!-- 建议放在 body 底部：确保 DOM 加载完成后再执行 JS，避免获取不到元素 -->  
    <!-- 路径说明：./js/main.js 是JS文件的相对路径 -->  
    <script src="./js/main.js"></script>  
</body>  
</html>  

```

--------------------------------

### Configure System Integration Resources

Source: https://developer.fnnas.com/docs/core-concepts/resource

Specify files to be symlinked into system directories (`/usr/local/bin`, `/usr/local/lib`, `/usr/local/etc`) upon application startup and removed upon shutdown.

```json
{
    "usr-local-linker": {
        "bin": [
            "bin/myapp-cli",
            "bin/myapp-server"
        ],
        "lib": [
            "lib/mylib.so",
            "lib/mylib.a"
        ],
        "etc": [
            "etc/myapp.conf",
            "etc/myapp.d/default.conf"
        ]
    }
}
```

--------------------------------

### 检查 Docker 应用启停状态脚本

Source: https://developer.fnnas.com/docs/core-concepts/docker

此脚本用于检查 Docker 应用的运行状态。它会读取 `docker-compose.yaml` 文件以获取容器名称，并使用 `docker inspect` 命令判断容器是否正在运行。默认情况下，Docker 应用的启停由应用中心管理。

```bash
#!/bin/bash  
  
FILE_PATH="${TRIM_APPDEST}/docker/docker-compose.yaml"  
  
is_docker_running () {  
    DOCKER_NAME=""  
  
    if [ -f "$FILE_PATH" ]; then  
        DOCKER_NAME=$(cat $FILE_PATH | grep "container_name" | awk -F ':' '{print $2}' | xargs)  
        echo "DOCKER_NAME is set to: $DOCKER_NAME"  
    fi  
  
  
    if [ -n "$DOCKER_NAME" ]; then  
        docker inspect $DOCKER_NAME | grep -q "\"Status\": \"running\"," || exit 1  
        return  
    fi  
}  
  
case $1 in  
start)  
    # run start command. exit 0 if success, exit 1 if failed  
    # do nothing, docker application will be started by appcenter  
    exit 0  
    ;;  
stop)  
    # run stop command. exit 0 if success, exit 1 if failed  
    # do nothing, docker application will be stopped by appcenter  
    exit 0  
    ;;  
status)  
    # check application status command. exit 0 if running, exit 3 if not running  
    # check first container by default, you cound modify it by yourself  
    if is_docker_running; then  
        exit 0  
    else  
        exit 3  
    fi  
    ;;  
*)  
    exit 1  
    ;;  
esac%
```

--------------------------------

### 编辑应用启停脚本 (main)

Source: https://developer.fnnas.com/docs/core-concepts/native

定义应用启动和停止时的执行逻辑，包括日志文件、PID 文件路径和环境变量设置。

```bash
#!/bin/bash

LOG_FILE="${TRIM_PKGVAR}/info.log"
PID_FILE="${TRIM_PKGVAR}/app.pid"

export PATH=/var/apps/nodejs_v22/target/bin:$PATH
# data directory to write note.txt
DATA_DIR="${TRIM_DATA_SHARE_PATHS%%:*}"
```

--------------------------------

### 配置 Root 权限模式

Source: https://developer.fnnas.com/docs/core-concepts/privilege

通过将 `run-as` 设置为 `root` 来启用 Root 权限模式，允许应用执行特权操作。此模式仅适用于官方合作企业开发者。

```json
{
    "defaults": {
        "run-as": "root"
    },
    "username": "myapp_user",
    "groupname": "myapp_group"
}

```

--------------------------------

### 创建飞牛 fnOS 应用打包目录

Source: https://developer.fnnas.com/docs/core-concepts/native

使用 fnpack 命令创建飞牛 fnOS 应用的打包目录结构。

```bash
fnpack create fnnas.notepad
```

--------------------------------

### Collect and Use Wizard Selections

Source: https://developer.fnnas.com/docs/core-concepts/wizard

This script demonstrates how to capture user selections from a wizard, including administrator username, password, database type, and application port. It then prints these values and conditionally configures the database based on the selected type.

```bash
ADMIN_USERNAME="$wizard_admin_username"
ADMIN_PASSWORD="$wizard_admin_password"
DATABASE_TYPE="$wizard_database_type"
APP_PORT="$wizard_app_port"

echo "管理员用户名: $ADMIN_USERNAME"
echo "数据库类型: $DATABASE_TYPE"
echo "应用端口: $APP_PORT"

if [ "$DATABASE_TYPE" = "mysql" ]; then
    echo "配置MySQL数据库..."
else
    echo "使用SQLite数据库..."
fi

```

--------------------------------

### 配置默认应用用户权限

Source: https://developer.fnnas.com/docs/core-concepts/privilege

使用 `config/privilege` 文件定义应用的默认运行身份为应用用户。如果未指定 `username` 和 `groupname`，系统将自动使用 `appname`。

```json
{
    "defaults": {
        "run-as": "package"
    },
    "username": "myapp_user",
    "groupname": "myapp_group"
}

```

--------------------------------

### Configure Java Environment

Source: https://developer.fnnas.com/docs/core-concepts/runtime

Configure the PATH to include the Java 21 OpenJDK bin directory. This ensures the correct java command is available in the current session.

```bash
# Optional versions: java-21-openjdk, java-17-openjdk, java-11-openjdk
export PATH=/var/apps/java-21-openjdk/target/bin:$PATH

# Confirm java version
java --version
```

--------------------------------

### 检查当前运行用户身份

Source: https://developer.fnnas.com/docs/core-concepts/privilege

在应用脚本中，使用环境变量 `TRIM_RUN_USERNAME` 和 `TRIM_USERNAME` 来检查当前运行的用户身份，并根据需要执行不同的逻辑。

```bash
#!/bin/bash

echo "当前运行用户: $TRIM_RUN_USERNAME"
echo "应用专用用户: $TRIM_USERNAME"

if [ "$TRIM_RUN_USERNAME" = "root" ]; then
    echo "应用以 root 权限运行"
else
    echo "应用以应用用户权限运行"
fi

```

--------------------------------

### Uninstallation Wizard Configuration

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Defines the steps for an uninstallation wizard, focusing on user confirmation for data handling, such as keeping or deleting application data.

```json
[
    {
        "stepTitle": "确认卸载",
        "items": [
            {
                "type": "tips",
                "helpText": "您即将卸载此应用。请选择如何处理应用数据："
            },
            {
                "type": "radio",
                "field": "wizard_data_action",
                "label": "数据保留选项",
                "initValue": "keep",
                "options": [
                    {
                        "label": "保留数据（推荐）- 将来重新安装时可恢复",
                        "value": "keep"
                    },
                    {
                        "label": "删除所有数据 - 此操作不可恢复！",
                        "value": "delete"
                    }
                ],
                "rules": [
                    {
                        "required": true,
                        "message": "请选择数据保留选项"
                    }
                ]
            },
            {
                "type": "tips",
                "helpText": "<strong>警告：</strong> 选择删除数据后，所有应用数据将永久丢失，无法恢复。"
            }
        ]
    }
]  
```

--------------------------------

### 复制编译产物到应用目录

Source: https://developer.fnnas.com/docs/core-concepts/native

将构建好的前端和后端代码复制到飞牛 fnOS 应用的指定目录中。

```bash
mkdir notepad/fnnas.notepad/app/server
cp -r notepad/dist/* notepad/fnnas.notepad/app/server/
```

--------------------------------

### Switch Toggle Configuration

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Implement a simple on/off switch for boolean settings, like enabling automatic backups. It has an initial value of 'true'.

```json
{
    "type": "switch",
    "field": "wizard_enable_backup",
    "label": "启用自动备份",
    "initValue": "true"
}
```

--------------------------------

### Configure Node.js Environment

Source: https://developer.fnnas.com/docs/core-concepts/runtime

Configure the PATH to include the Node.js v22 bin directory. This ensures the correct node and npm commands are available in the current session.

```bash
# Optional versions: nodejs_v22, nodejs_v20, nodejs_v18, nodejs_v16, nodejs_v14
export PATH=/var/apps/nodejs_v22/target/bin:$PATH

# Confirm node version
node -v

# Confirm npm version
npm -v
```

--------------------------------

### App Directory Structure

Source: https://developer.fnnas.com/docs/quick-started/create-application

Defines the expected file and folder organization for the HelloFnosAppCenter application.

```plaintext
HelloFnosAppCenter  
├── css  
│   └── style.css  
├── images  
│   └── logo.png  
├── index.html  
└── js  
    └── main.js  

```

--------------------------------

### Configure Data Sharing Resources

Source: https://developer.fnnas.com/docs/core-concepts/resource

Define directories to share with users and their access permissions (read-only or read-write). Shares are visible in the system's file manager under 'Application Files'.

```json
{
    "data-share": {
        "shares": [
            {
                "name": "documents",
                "permission": {
                    "rw": ["myapp_user"]
                }
            },
            {
                "name": "documents/backups",
                "permission": {
                    "ro": ["myapp_user"]
                }
            }
        ]
    }
}
```

--------------------------------

### 构建前端和后端

Source: https://developer.fnnas.com/docs/core-concepts/native

执行构建命令以生成可执行文件，为部署到飞牛 fnOS 做准备。

```bash
npm run build
```

--------------------------------

### Configure Docker Project Resources

Source: https://developer.fnnas.com/docs/core-concepts/resource

Define Docker Compose projects, specifying their name and the relative path to the directory containing the `docker-compose.yaml` file.

```json
{
    "docker-project": {
        "projects": [
            {
                "name": "myapp-stack",
                "path": "docker"
            }
        ]
    }
}
```

--------------------------------

### Select Dropdown Configuration

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Configure a dropdown select box for choosing one option from a list, such as database types. A selection is mandatory.

```json
{
    "type": "select",
    "field": "wizard_database_type",
    "label": "数据库类型",
    "initValue": "sqlite",
    "options": [
        {
            "label": "SQLite (推荐)",
            "value": "sqlite"
        },
        {
            "label": "MySQL",
            "value": "mysql"
        },
        {
            "label": "PostgreSQL",
            "value": "postgresql"
        }
    ],
    "rules": [
        {
            "required": true,
            "message": "请选择数据库类型"
        }
    ]
}
```

--------------------------------

### 编辑应用配置 (resource)

Source: https://developer.fnnas.com/docs/core-concepts/native

配置应用的数据共享和读写权限，允许应用访问和修改共享数据。

```json
{
    "data-share": {
        "shares": [
            {
                "name": "fnnas.notepad",
                "permission": {
                    "rw": [
                        "fnnas.notepad"
                    ]
                }
            }
        ]
    }
}
```

--------------------------------

### CSS Styling for App Center Demo

Source: https://developer.fnnas.com/docs/quick-started/create-application

Provides CSS for styling the App Center demo page, including global resets, body background, logo, and text elements with hover effects.

```css
/* 全局样式重置 */  
* {  
    margin: 0;  
    padding: 0;  
    box-sizing: border-box;  
}  
  
/* 页面整体样式 */  
body {  
    font-family: "Microsoft YaHei", sans-serif; /* 字体设置 */  
    background: linear-gradient(120deg, #5f85ff, #48e08f); ; /* 页面蓝绿渐变背景*/  
    min-height: 100vh; /* 页面高度占满视口 */  
    display: flex; /* Flex布局：让内容垂直+水平居中 */  
    flex-direction: column;  
    align-items: center;  
    justify-content: center;  
    gap: 30px; /* 元素之间的间距 */  
    /* 渐变背景防重复 */  
    background-repeat: no-repeat;  
}  
  
/* Logo容器样式 */  
.logo-container {  
    width: 120px; /* 容器宽度 */  
    height: 120px; /* 容器高度 */  
    border-radius: 50%; /* 圆形容器 */  
    overflow: hidden; /* 裁剪超出容器的图片 */  
    border: 3px solid #2563eb; /* 边框样式 */  
    box-shadow: 0 0 15px rgba(37, 99, 235, 0.4); /* 阴影效果 */  
}  
  
/* Logo图片样式 */  
.logo {  
    width: 100%; /* 图片宽度占满容器 */  
    height: 100%; /* 图片高度占满容器 */  
    object-fit: cover; /* 图片等比缩放，填充容器 */  
    cursor: pointer; /* 鼠标悬浮显示手型 */  
    transition: transform 0.3s ease; /* 过渡动画（教学点：CSS动画） */  
}  
  
/* Logo悬浮效果 */  
.logo:hover {  
    transform: scale(1.2); /* 鼠标悬浮放大1.2倍 */  
}  
  
.hello-container {  
    text-align: center; /* 文本居中 */  
}  
  
#helloText {  
    font-size: 48px; /* 字体大小 */  
    color: #303133; /* 字体颜色 */  
    transition: all 0.3s ease; /* 过渡动画 */  
    cursor: pointer;  
}  
  
/* 标题悬浮效果 */  
#helloText:hover {  
    color: #2563eb; /* 悬浮变色 */  
    transform: translateY(-5px); /* 悬浮上移 5px */  
    /* 新增文字阴影，增强视觉层次 */  
    text-shadow: 0 2px 8px rgba(37, 99, 235, 0.3)  
}  
  
/* 提示文本样式 */  
.tips {  
    margin-top: 15px;  
    font-size: 16px;  
    color: #64748b;  
}  

```

--------------------------------

### 安装和启动本地应用

Source: https://developer.fnnas.com/docs/core-concepts/native

在本地开发环境中安装项目依赖并启动应用，用于开发和测试。

```bash
npm install --workspaces
npm run start
```

--------------------------------

### Tips Text Display

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Use this to display informational text, links, or warnings to the user. It does not collect input.

```json
{
    "type": "tips",
    "helpText": "请阅读 <a target="_blank" href="https://example.com/privacy">隐私政策</a> 了解我们如何处理您的数据。"
}
```

--------------------------------

### 编辑应用权限 (privilege)

Source: https://developer.fnnas.com/docs/core-concepts/native

定义应用运行的用户和组，确保应用以指定的权限运行。

```json
{
    "defaults": {
        "run-as": "package"
    },
    "username": "fnnas.notepad",
    "groupname": "fnnas.notepad"
}
```

--------------------------------

### 编辑应用基本信息 (manifest)

Source: https://developer.fnnas.com/docs/core-concepts/native

配置飞牛 fnOS 应用的元数据，包括名称、版本、描述、架构等。

```properties
appname=fnnas.notepad
version=0.0.1
desc=A simple notepad
arch=x86_64
display_name=Notepad
maintainer=someone
distributor=someone
desktop_uidir=ui
desktop_applaunchname=fnnas.notepad.Application
source=thirdparty
```

--------------------------------

### Wizard File Structure

Source: https://developer.fnnas.com/docs/core-concepts/wizard

A wizard is defined as a JSON array, where each object represents a step with a title and a list of form items.

```json
[
    {
        "stepTitle": "第一步标题",
        "items": [
            // 表单项列表
        ]
    },
    {
        "stepTitle": "第二步标题",
        "items": [
            // 表单项列表
        ]
    }
]
```

--------------------------------

### Accessing Wizard Input via Environment Variables

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Explains that user selections from the wizard are converted into environment variables, using the field name directly as the variable name.

```bash
#!/bin/bash  
  
```

--------------------------------

### Define Nested Dependencies (Flattened)

Source: https://developer.fnnas.com/docs/core-concepts/dependency

The application center only checks one level of dependency. For nested dependencies (e.g., App A depends on App B, and App B depends on App C), you must explicitly declare all dependencies in the `manifest` file by listing them all in `install_dep_apps`.

```properties
# 嵌套依赖的平铺定义  
install_dep_apps=depB:depC  

```

--------------------------------

### JavaScript for App Center Interaction

Source: https://developer.fnnas.com/docs/quick-started/create-application

Adds interactivity to the App Center demo page by handling click events on the heading to change text and display an alert.

```javascript
// 教学点1：DOM 获取元素  
const helloText = document.getElementById('helloText');  
  
// 教学点2：绑定点击事件（交互核心）  
helloText.addEventListener('click', function() {  
    // 教学点3：修改 DOM 内容（动态改变文本）  
    const originalText = 'Hello fnOS AppCenter !';  
    const newText = '👋 你好，飞牛应用中心先锋开发者！';  
      
    if (helloText.innerText === originalText) {  
        helloText.innerText = newText;  
        // 教学点4：弹出提示框（基础交互）  
        alert('🎉 JS交互生效啦！文本已修改～');  
    } else {  
        helloText.innerText = originalText; // 还原文本  
    }  
});  
  
// 教学点5：控制台输出（调试常用）  
console.log('✅ 外部JS文件加载成功！');  
console.log('🔍 当前点击的元素：', helloText);  

```

--------------------------------

### Password Input Field Configuration

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Configure a password input field for sensitive information. Input is masked with asterisks and can have minimum length requirements.

```json
{
    "type": "password",
    "field": "wizard_password",
    "label": "管理员密码",
    "rules": [
        {
            "required": true,
            "message": "请输入密码"
        },
        {
            "min": 6,
            "message": "密码长度不能少于6位"
        }
    ]
}
```

--------------------------------

### Write Error to Log and Exit

Source: https://developer.fnnas.com/docs/core-concepts/framework

This snippet demonstrates how to write an error message to the TRIM_TEMP_LOGFILE environment variable and exit with an error code of 1. This is used for custom error reporting in scripts.

```bash
echo "Error: Something went wrong" > $TRIM_TEMP_LOGFILE  
exit 1  
```

--------------------------------

### Text Input Field Configuration

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Use this for collecting user text input like usernames or emails. It supports required and length validation rules.

```json
{
    "type": "text",
    "field": "wizard_username",
    "label": "用户名",
    "initValue": "admin",
    "rules": [
        {
            "required": true,
            "message": "请输入用户名"
        },
        {
            "min": 3,
            "max": 20,
            "message": "用户名长度应在3-20个字符之间"
        }
    ]
}
```

--------------------------------

### Exact Length Validation Rule

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Use this rule to ensure the input has a specific, exact length, such as for verification codes.

```json
{
    "len": 6,
    "message": "请输入6位验证码"
}
```

--------------------------------

### Regular Expression Validation Rule

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Configure validation using a regular expression pattern to match specific character sets or formats.

```json
{
    "pattern": "^[a-zA-Z0-9_]+$",
    "message": "只能包含字母、数字和下划线"
}
```

--------------------------------

### Length Restriction Validation Rule

Source: https://developer.fnnas.com/docs/core-concepts/wizard

Apply this rule to limit the input length to a minimum and maximum character count.

```json
{
    "min": 3,
    "max": 50,
    "message": "长度应在3-50个字符之间"
}
```

--------------------------------

### Required Field Validation Rule

Source: https://developer.fnnas.com/docs/core-concepts/wizard

This rule enforces that a field must not be empty.

```json
{
    "required": true,
    "message": "此字段不能为空"
}
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.