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https://github.com/lisez/xevt
another event emiiter.
https://github.com/lisez/xevt
emitter event event-bus event-emitter event-listener javascript typescript
Last synced: 3 months ago
JSON representation
another event emiiter.
- Host: GitHub
- URL: https://github.com/lisez/xevt
- Owner: lisez
- License: mit
- Created: 2024-05-17T15:49:46.000Z (7 months ago)
- Default Branch: main
- Last Pushed: 2024-05-22T12:46:40.000Z (7 months ago)
- Last Synced: 2024-05-22T13:57:24.498Z (7 months ago)
- Topics: emitter, event, event-bus, event-emitter, event-listener, javascript, typescript
- Homepage:
- Size: 21.5 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# xevt
another event emiiter.
features:
- can listen async/conjoined event.
- support to mixed async/sync handlers
- conditional event handlers.
- return unscriber when you subscribe an event.
[](https://coveralls.io/github/lisez/xevt) [](https://opensource.org/licenses/MIT) [](https://github.com/lisez/xevt/releases) [](https://www.npmjs.com/package/xevt) [](https://jsr.io/@lisez/xevt)
## Installation
```bash
npm install xevt
```
Then:
```typescript
import { Xevt } from "xevt";
```
## Usage
### Basic usage
```typescript
const emitter = new Xevt();
let result = 0;
emitter.on("event", () => {
result++;
});
emitter.emit("event");
```
### Async event
```typescript
const emitter = new Xevt();
let result = 0;
emitter.on("event", async () => {
result++;
});
await emitter.emit("event");
```
### Conditional event handlers.
IMPORTANT:
- NOT supported in conjoined events.
- NOT supported any arguments in handlers.
- It will be executed after the triggered event finished. (Blocking mode.)
```typescript
const emitter = new Xevt();
const result: any[] = [];
emitter.on("event", async (arg: number) => {
result.push(arg);
return arg % 2 === 0;
});
emitter.on("event", {
true: async () => {
result.push("first");
},
});
emitter.on("event", {
false: async () => {
result.push("fail");
},
});
emitter.on("event", {
true: () => {
result.push(100);
},
false: () => {
result.push(99);
},
});
emitter.emit("event", 1);
emitter.emit("event", 2);
await delay(10);
// [1, "fail", 99, 2, "first", 100]
```
### Conjoined event
IMPORTANT: conjoined events are not supported any arguments in handlers.
```typescript
const emitter = new Xevt();
let count = 0;
emitter.on(["event1", "event2"], () => {
count++;
});
emitter.emit("event1");
emitter.emit("event2");
console.log(count); // 1
```
### Mixed async/sync handlers
Non-blocking in default.
```typescript
const emitter = new Xevt();
const result: number[] = [];
emitter.on("event", (data) => {
result.push(data);
});
emitter.on(
"event",
async (data) =>
new Promise((res) => {
setTimeout(() => {
result.push(data);
res(true);
}, 10);
}),
);
for (let i = 0; i < 5; i++) {
emitter.emit("event", i);
}
// [0, 1, 2, 3, 4, 0, 1, 2, 3, 4]
```
Blocking mode.
```typescript
const emitter = new Xevt();
const result: number[] = [];
emitter.on("event", (data) => {
result.push(data);
});
emitter.on(
"event",
// deno-lint-ignore require-await
async (data) =>
new Promise((res) => {
setTimeout(() => {
result.push(data);
res(true);
}, 1);
}),
{ async: true },
);
for (let i = 0; i < 5; i++) {
emitter.emit("event", i);
}
await delay(15);
// [0, 0, 1, 1, 2, 2, 3, 3, 4, 4]
```
## Return unscriber after registered an event
```typescript
const emitter = new Xevt();
const result: number[] = [];
const unscribe = emitter.on("event", (arg: number) => {
result.push(arg);
});
unscribe();
```
```typescript
const emitter = new Xevt();
const result: number[] = [];
const unscribe = emitter.conjoin(["event1", "event2"], () => {
result.push(1);
});
unscribe();
```
### Debug mode
```typescript
const emitter = new Xevt();
emitter.debug = true;
```
Then you can see the debug information in the console.
## Similar projects
- [mitt](https://github.com/developit/mitt)
- [emittery](https://github.com/sindresorhus/emittery)
- [eventemitter3](https://github.com/primus/eventemitter3)
- [evt](https://github.com/garronej/evt)