
- Complete NestJS TypeScript implementation with WebSocket support - Direct messaging (DM) and group chat functionality - End-to-end encryption with AES encryption and key pairs - Media file support (images, videos, audio, documents) up to 100MB - Push notifications with Firebase Cloud Messaging integration - Mention alerts and real-time typing indicators - User authentication with JWT and Passport - SQLite database with TypeORM entities and relationships - Comprehensive API documentation with Swagger/OpenAPI - File upload handling with secure access control - Online/offline status tracking and presence management - Message editing, deletion, and reply functionality - Notification management with automatic cleanup - Health check endpoint for monitoring - CORS configuration for cross-origin requests - Environment-based configuration management - Structured for Flutter SDK integration Features implemented: ✅ Real-time messaging with Socket.IO ✅ User registration and authentication ✅ Direct messages and group chats ✅ Media file uploads and management ✅ End-to-end encryption ✅ Push notifications ✅ Mention alerts ✅ Typing indicators ✅ Message read receipts ✅ Online status tracking ✅ File access control ✅ Comprehensive API documentation Ready for Flutter SDK development and production deployment.
1.7 KiB
1.7 KiB
once
Only call a function once.
usage
var once = require('once')
function load (file, cb) {
cb = once(cb)
loader.load('file')
loader.once('load', cb)
loader.once('error', cb)
}
Or add to the Function.prototype in a responsible way:
// only has to be done once
require('once').proto()
function load (file, cb) {
cb = cb.once()
loader.load('file')
loader.once('load', cb)
loader.once('error', cb)
}
Ironically, the prototype feature makes this module twice as complicated as necessary.
To check whether you function has been called, use fn.called
. Once the
function is called for the first time the return value of the original
function is saved in fn.value
and subsequent calls will continue to
return this value.
var once = require('once')
function load (cb) {
cb = once(cb)
var stream = createStream()
stream.once('data', cb)
stream.once('end', function () {
if (!cb.called) cb(new Error('not found'))
})
}
once.strict(func)
Throw an error if the function is called twice.
Some functions are expected to be called only once. Using once
for them would
potentially hide logical errors.
In the example below, the greet
function has to call the callback only once:
function greet (name, cb) {
// return is missing from the if statement
// when no name is passed, the callback is called twice
if (!name) cb('Hello anonymous')
cb('Hello ' + name)
}
function log (msg) {
console.log(msg)
}
// this will print 'Hello anonymous' but the logical error will be missed
greet(null, once(msg))
// once.strict will print 'Hello anonymous' and throw an error when the callback will be called the second time
greet(null, once.strict(msg))