Package - sdk-base

sdk-base

A base class for sdk with some common & useful functions.

Installation

$ npm install sdk-base

Usage

Constructor argument:

{Object} options

{String} [initMethod] - the async init method name, the method should be a function return promise. If set, will execute the function in the constructor.
{AsyncLocalStorage} [localStorage] - async localStorage instance.

const Base = require('sdk-base');

class Client extends Base {
  constructor() {
    super({
      initMethod: 'init',
      localStorage: app.ctxStorage,
    });
  }

  async init() {
    // put your async init logic here
  }
  // support async function too
  // async init() {
  //   // put your async init logic here
  // }
}

(async function main() {
  const client = new Client();
  // wait client ready, if init failed, client will throw an error.
  await client.ready();

  // support async event listener
  client.on('data', async function (data) {
    // put your async process logic here
    //
    // @example
    // ----------
    // await submit(data);
  });

  client.emit('data', { foo: 'bar' });

})().catch(err => { console.error(err); });

API

.ready(flagOrFunction) flagOrFunction is optional, and the argument type can be Boolean, Error or Function.

// init ready
client.ready(true);
// init failed
client.ready(new Error('init failed'));

// listen client ready
client.ready(err => {
  if (err) {
    console.log('client init failed');
    console.error(err);
    return;
  }
  console.log('client is ready');
});

// support promise style call
client.ready()
  .then(() => { ... })
  .catch(err => { ... });

// support async function style call
await client.ready();

async readyOrTimeout(milliseconds) ready or timeout, after milliseconds not ready will throw TimeoutError
```
await client.readyOrTimeout(100);
```
.isReady getter detect client start ready or not.
.on(event, listener) wrap the EventEmitter.prototype.on(event, listener), the only difference is to support adding async function listener on events, except 'error' event.
once(event, listener) wrap the EventEmitter.prototype.once(event, listener), the only difference is to support adding async function listener on events, except 'error' event.
prependListener(event, listener) wrap the EventEmitter.prototype.prependListener(event, listener), the only difference is to support adding async function listener on events, except 'error' event.
prependOnceListener(event, listener) wrap the EventEmitter.prototype.prependOnceListener(event, listener), the only difference is to support adding generator listener on events, except 'error' event.

addListener(event, listener) wrap the EventEmitter.prototype.addListener(event, listener), the only difference is to support adding async function listener on events, except 'error' event.

client.on('data', async function(data) {
  // your async process logic here
});
client.once('foo', async function(bar) {
  // ...
});

// listen error event
client.on('error', err => {
  console.error(err.stack);
});

.await(event): await an event, return a promise, and it will resolve(reject if event is error) once this event emmited.
```
const data = await client.await('data');
```

.awaitFirst(event): await the first event in a set of event pairs, return a promise, and it will clean up after itself.

(async function main() {
  const o = await client.awaitFirst([ 'foo', 'bar' ]);
  if (o.event === 'foo') {
    // ...
  }
  if (o.event === 'bar') {
    // ...
  }
})();

._close(): The _close() method is called by close, It can be overridden by child class, but should not be called directly. It must return promise or generator.
.close(): The close() method is used to close the instance.