---
title: config - 配置 API
sidebar_position: 8
---
> **@types** [IPublicModelEngineConfig](https://github.com/alibaba/lowcode-engine/blob/main/packages/types/src/shell/model/engine-config.ts)
> **@since** v1.0.0
## 模块简介
配置模块，负责配置的读、写等操作。
## 方法
### get
获取指定 key 的值
```typescript
/**
* 获取指定 key 的值
* get value by key
* @param key
* @param defaultValue
* @returns
*/
get(key: string, defaultValue?: any): any;
```
#### 示例
```typescript
import { config } from '@alilc/lowcode-engine';
config.get('keyA', true);
config.get('keyB', { a: 1 });
```
### set
设置指定 key 的值
```typescript
/**
* 设置指定 key 的值
* set value for certain key
* @param key
* @param value
*/
set(key: string, value: any): void;
```
#### 示例
```typescript
import { config } from '@alilc/lowcode-engine';
config.set('keyC', 1);
```
### has
判断指定 key 是否有值
```typescript
/**
* 判断指定 key 是否有值
* check if config has certain key configed
* @param key
* @returns
*/
has(key: string): boolean;
```
#### 示例
```typescript
import { config } from '@alilc/lowcode-engine';
config.has('keyD');
```
### setConfig
批量设值，set 的对象版本
```typescript
/**
* 批量设值，set 的对象版本
* set multiple config key-values
* @param config
*/
setConfig(config: { [key: string]: any }): void;
```
#### 示例
```typescript
import { config } from '@alilc/lowcode-engine';
config.setConfig({ keyA: false, keyB: 2 });
```
### getPreference
获取全局 Preference 管理器，用于管理全局浏览器侧用户 Preference，如 Panel 是否钉住
```typescript
/**
* 获取全局 Preference, 用于管理全局浏览器侧用户 Preference，如 Panel 是否钉住
* get global user preference manager, which can be use to store
* user`s preference in user localstorage, such as a panel is pinned or not.
* @returns {IPublicModelPreference}
* @since v1.1.0
*/
getPreference(): IPublicModelPreference;
```
相关类型：[IPublicModelPreference](https://github.com/alibaba/lowcode-engine/blob/main/packages/types/src/shell/model/preference.ts)
**@since v1.1.0**
示例
```javascript
import { config } from '@alilc/lowcode-engine';
const panelName = 'outline-master-pane';
// 设置大纲树面板钉住，在大纲树下次重新打开时生效
config.getPreference().set(`${panelName}-pinned-status-isFloat`, false, 'skeleton')
```
## 事件
### onceGot
获取指定 key 的值，若此时还未赋值，则等待，若已有值，则直接返回值
注：此函数返回 Promise 实例
```typescript
/**
* 获取指定 key 的值，若此时还未赋值，则等待，若已有值，则直接返回值
* 注：此函数返回 Promise 实例，只会执行（fullfill）一次
* wait until value of certain key is set, will only be
* triggered once.
* @param key
* @returns
*/
onceGot(key: string): Promise;
```
#### 示例
```typescript
import { config } from '@alilc/lowcode-engine';
config.onceGot('keyA').then(value => {
console.log(`The value of keyA is ${value}`);
});
// or
const value = await config.onceGot('keyA');
```
### onGot
获取指定 key 的值，函数回调模式，若多次被赋值，回调会被多次调用
```typescript
/**
* 获取指定 key 的值，函数回调模式，若多次被赋值，回调会被多次调用
* set callback for event of value set for some key
* this will be called each time the value is set
* @param key
* @param fn
* @returns
*/
onGot(key: string, fn: (data: any) => void): () => void;
```
#### 示例
```typescript
import { config } from '@alilc/lowcode-engine';
config.onGot('keyA', (value) => {
console.log(`The value of keyA is ${value}`);
});
const.set('keyA', 1); // 'The value of keyA is 1'
const.set('keyA', 2); // 'The value of keyA is 2'
```