@twitter-api-v2/plugin-cache-core

> Provide core utils to create a request cache plugin for twitter-api-v2

This package is meant to be used by other plugin packages, and can't be used alone.

Usage

``ts
import { TwitterApiCachePluginCore } from '@twitter-api-v2/plugin-cache-core';

class MyRequestCachePlugin extends TwitterApiCachePluginCore {
// You must write those methods with the following signatures:
protected hasKey(key: string): boolean | Promise;

protected getKey(key: string): TwitterResponse | undefined | Promise | undefined>;

protected setKey(key: string, response: TwitterResponse): void | Promise;
}
`

then, use your plugin into twitter-api-v2:

`ts
import { TwitterApi } from 'twitter-api-v2';
import { MyRequestCachePlugin } from './your-plugin';

const client = new TwitterApi(yourKeys, { plugins: [new MyRequestCachePlugin()] });
`

Defaults and customization

$3

- a key is generated from a request using request URL and parameters
- cached requests are ONLY requests for GET method
- request key is not scoped by user/token, so if you're using a shared key/value storage (like file system or Redis), cache will be shared across all client instances

$3

#### Key generation

If you just want to add a prefix to the key, you can customize this by overriding the .getKeyPrefix() method:

`ts
class MyRequestCachePlugin extends TwitterApiCachePluginCore {
protected getKeyPrefix() {
return 'prefix-';
}
}
`

If you want to generate key by yourself, override the .getRequestKey() method:

`ts
class MyRequestCachePlugin extends TwitterApiCachePluginCore {
protected getRequestKey({ url, params }: ITwitterApiBeforeRequestConfigHookArgs) {
const method = params.method.toUpperCase();
// Ignore request params/query, just use URL + method
return this.getHashOfString(${method} ${url.toString()});
}
}
`

#### Cached requests are ONLY requests for GET method

You can customize this by overriding the .isRequestCacheable() method.
If you accept other methods than GET, you might need to rewrite the .getRequestKey() method, because the base one ignores a possible request body.

`ts
class MyRequestCachePlugin extends TwitterApiCachePluginCore {
protected isRequestCacheable(args: ITwitterApiBeforeRequestConfigHookArgs) {
const method = args.params.method.toUpperCase();
// Accept GET and DELETE
return method === 'GET' || method === 'DELETE';
}
}
`

#### Request key is not scoped by user/token

You can customize this, for example, by overriding the .getKeyPrefix() method and using a user ID as key prefix:

`ts
class UserScopedRequestCachePlugin extends TwitterApiCachePluginCore {
constructor(protected userId: string) {
super();
}

protected getKeyPrefix() {
return this.userId;
}
}

const client = new TwitterApi(user.twitterKeys, { plugins: [new UserScopedRequestCachePlugin(user.id)] });
`

If you want to have unique cache per plugin instance, but your storage is shared, you can generate a unique prefix in constructor:

`ts
import * as crypto from 'crypto';

class UniqueRequestCachePlugin extends TwitterApiCachePluginCore {
protected uniqueId: string;

constructor() {
super();
this.uniqueId = crypto.randomBytes(16).toString('hex');
}

protected getKeyPrefix() {
return this.uniqueId;
}
}

const client = new TwitterApi(yourKeys, { plugins: [new UniqueRequestCachePlugin()] });
``