nestjs-cache-decorator

NestJS Cache Decorator · npm version
A custom decorator is implemented in Nestjs to provide convenience for caching, called the 'cache decorator'.


## Table of Contents
  1. Installation
  2. Configuration
  3. Usage (Controller)
  4. Usage (Provider)
  5. License
## Installation ```sh npm install nestjs-cache-decorator pnpm install nestjs-cache-decorator ``` ## Configuration ### Static redis cache configuration ```typescript import {Module} from "@nestjs/common"; import {LocalCacheDecoratorModule} from "nestjs-cache-decorator"; import redisStore from "cache-manager-redis-store"; @Module({ imports: [ CacheDecoratorModule.register({ host: "host", port: 6379, password: "password", db: 0, store: redisStore, }), ], }) export class AppModule { } ``` ### Static local cache configuration ```typescript import {Module} from "@nestjs/common"; import {LocalCacheDecoratorModule} from "nestjs-cache-decorator"; @Module({ imports: [ CacheDecoratorModule.register({}), // default `store: "memory"` ], }) export class AppModule { } ``` ### Async redis cache configuration ```typescript import {Module} from "@nestjs/common"; import {LocalCacheDecoratorModule} from "nestjs-cache-decorator"; import redisStore from "cache-manager-redis-store"; @Module({ imports: [ CacheDecoratorModule.registerAsync({ imports: [ConfigModule], inject: [ConfigService], useFactory: async (configService: ConfigService): Promise => { const config = configService.get("redis"); return {...config, store: redisStore}; }, }), ], }) export class AppModule { } ``` ## Usage (Controller) `@APICache({})` The first cache module that is imported will serve as the storage for the controller cache. For instance, in this scenario, the controller's cache storage would be set to "memory". ```typescript @Module({ imports: [ CacheDecoratorModule.register({ store: "memory"}), CacheDecoratorModule.register({ store : redisStore}), ], }) export class AppModule { ``` If the `key` field is empty, the default cache key will be **HTTP URL Path** where `/` is replaced to `:`. If the `key` field exists, the cache key will be `{http url path}:{http url path}:...:{key}`. Use the `validate` filed function to verify the result of the method. The `logger` creates a log when data is cached or when there is a cache hit. When the `logger` is set to `console.log`, the output will be as follows: - When data is cached : `Cached { cacheKey: 'example:redis' }` - When cache hit : `Cache Hit { cacheKey: 'example:redis' }` ```typescript @Controller("example") @UseInterceptors(ControllerCacheInterceptor) export class ExampleController { @RedisCache({ ttl: 60, validate: (value: any) => Boolean(value), logger: console.log, }) @Get("redis") async example() { } } ``` ## Usage (Provider) `@RedisCache({})`, `@LocalCache({})` If the `key` field is empty, the default cache key will be `{className}:{methodName}:{methodArgs}`. If the `key` field exists, the cache key will be `{className}:{methodName}:{key}`. Use the `validate` filed function to verify the result of the method. The `logger` creates a log when data is cached or when there is a cache hit. When the `logger` is set to `console.log`, the output will be as follows: - When data is cached : `Cached { cacheKey: 'ExampleService:cacheExample:test' }` - When cache hit : `Cache Hit { cacheKey: 'ExampleService:cacheExample:test' }` ### Cache by TTL Caching takes place when the function `cacheExample()` is called and the result is not already cached. The cache will expire after the TTL (Time To Live) duration. ```typescript @Injectable() export class ExampleService { @RedisCache({ ttl: 60, // expire after 60s key: "test", // cache key : `ExampleService:cacheExample:test` validate: (value: any) => Boolean(value), logger: console.log, }) redisCacheExample() { } @LocalCache({ ttl: 60, // expire after 60s key: "test", // cache key : `ExampleService:cacheExample:test` validate: (value: any) => Boolean(value), logger: console.log, }) localCacheExample() { } } ``` ### Cache by Cron For the example below, `cacheExample()` method will be called each time the current second is 45. In other words, the method will be run once per minute, at the 45 second mark. The `cron` field supports all standard [cron patterns](http://crontab.org/): - Asterisk (e.g. *) - Ranges (e.g. 1-3,5) - Steps (e.g. */2) ```typescript @Injectable() export class ExampleService { @RedisCache({ cron: "45 * * * * *", // The method is executed every 45 second, and the result is cached. key: "test", validate: (value: any) => Boolean(value), logger: console.log, }) redisCacheExample() { } @LocalCache({ cron: "45 * * * * *", // The method is executed every 45 second, and the result is cached. key: "test", validate: (value: any) => Boolean(value), logger: console.log, }) localCacheExample() { } } ``` In the example above, we passed `45 * * * * *` to the decorator. The following key shows how each position in the cron pattern string is interpreted: ```typescript * * * * * * | | | | | | | | | | | day of week | | | | months | | | day of month | | hours | minutes seconds (optional) ``` ### Decorator options ```typescript export interface CacheOptions { cron?: string; key?: string; ttl?: number; validate?: Function; logger?: Function; } ```