config middleware

Install and use

The config middleware is an independent middleware and needs to be installed and used separately

npm i sener-config

import { Static } from 'sener-config';
new Static();

Basic usage

The config middleware is used to configure some server-side parameters, saved as a json file, and supports dynamic modification to take effect immediately.

import { Sener, Router } from 'sener';
import { Config } from 'sener-config';

const router = new Router({
     '/demo': ({ config }) => {
         console.log(config.level); // get level configuration
         return { data: {success: true} };
     },
});

new Sener({
   middlewares: [router, new Config()],
});

Construction parameters

The config middleware supports the following configurations:

type IConfigChange = (data: {
   key: string, value: any, prev: any
}) => void;

interface IConfigOptions {
     dir?: string, // The storage directory of the configuration file. The default is 'config', which is {Sener.Dir}/config
     format?: boolean, // Whether to format the configuration file, the default is true
     initial?: Record<string, Record<string, any>>, // Initial configuration data. The default value is {_default: {}}
     onchange?: IConfigChange; // Callback function for configuration data changes
}

dir can be configured with a relative path, which means relative to Sener.Dir, or an absolute path can be configured

Initial configuration data

The initial configuration data is a piece of data, the element contains filename and data, indicating a configuration file, and multiple means that multiple configuration files need to be used

new Config({
    //User configuration file, stored as user.json
    user: {
        showImage: true, // Configure whether to display the avatar
        maxVisitors: 999, // Configure the maximum visible visitors
    },
    goods: { // Product configuration file, stored as goods.json
        maxPrice: 9999,
        // ...
    }
});

Note:

1. If the file in initial does not exist, the data will be created and written. If it exists, the data will be merged into the data in the original file. The merging rule is to only replace the undefined attribute in the original file without modifying it. Existing attributes, and will traverse the original data in depth.
2. After all the data in the initial file is merged with the data in the original file (if it exists), all attributes will be merged into a map, which is the config object of SenerContext. config[key] can be read and set to the latest json file data

Custom SenerContext

The config middleware has only one Context attribute, which is config

You can use attributes to get or assign values directly, or you can listen to configuration file changes through the $onchange method

const router = new Router({
     '/demo': ({ config }) => {
         console.log(config.level); // get level configuration
         config.level = 3;
         config. $onchange = (key, value, prev) => {
             console.log(key, value, prev);
         }
         return { data: {success: true} };
     },
});

API

The config-middleware object has the following APIs that can be used directly

data

data is equivalent to SenerContext.config

const config = new Config();
config.data.$onchange(()=>{});
config.data.level = 1;

writeConfig

writeConfig is equivalent to config.data.xxx = xxx;

const config = new Config();
config.writeConfig('age', 1);

###onConfigChange

onConfigChange is equivalent to config.data.$onchange

const config = new Config();
config.onConfigChange(()=>{});

ts type declaration

If you want to declare the type of config data, you can use the following code to extend it:

declare module 'sener-extend' {
     interface IConfigData {
         level: number,
         age: number,
     }
}