# Signal
> **API Reference** ▸ **Signal**
Signal is a function with listeners which can be emitted.
Access it with:
```javascript
const { signal } = Neft;
```
> [`Source`](https://github.com/Neft-io/neft/blob/f9c128ccb37aa79380c961e878cd76ec9e79c99e/src/signal/index.litcoffee)
* * *
### `signal.STOP_PROPAGATION`
- Static property of
- signal
- Type
- Integer
Special constant used to stop calling further listeners.
Must be returned by the listener function.
```javascript
var obj = {};
signal.create(obj, 'onPress');
obj.onPress(function(){
console.log('listener 1');
return signal.STOP_PROPAGATION;
});
// this listener won't be called, because first listener will capture this signal
obj.onPress(function(){
console.log('listener 2');
});
obj.onPress.emit();
// listener 1
```
> [`Source`](https://github.com/Neft-io/neft/blob/f9c128ccb37aa79380c961e878cd76ec9e79c99e/src/signal/index.litcoffee#integer-signalstoppropagation)
* * *
### `signal.create()`
- Static property of
- signal
- Parameters
- object — NotPrimitive — optional
- name — String — optional
- Type
- Signal
Creates a new signal in the given object under the given name property.
Returns created signal.
```javascript
var obj = {};
signal.create(obj, 'onRename');
obj.onRename.connect(function(){
console.log(arguments);
});
obj.onRename.emit('Max', 'George');
// {0: "Max", 1: "George"}
```
> [`Source`](https://github.com/Neft-io/neft/blob/f9c128ccb37aa79380c961e878cd76ec9e79c99e/src/signal/index.litcoffee#signal-signalcreatenotprimitive-object-string-name)
* * *
### `signal.isEmpty()`
- Static method of
- signal
- Parameters
- Returns
- Boolean
Returns `true` if the given signal has no listeners.
> [`Source`](https://github.com/Neft-io/neft/blob/f9c128ccb37aa79380c961e878cd76ec9e79c99e/src/signal/index.litcoffee#boolean-signalisemptysignal-signal)
* * *
### `emit()`
- Parameters
- argument1 — Any — optional
- argument2 — Any — optional
Call all of the signal listeners with the given arguments (2 maximally).
> [`Source`](https://github.com/Neft-io/neft/blob/f9c128ccb37aa79380c961e878cd76ec9e79c99e/src/signal/index.litcoffee#signalemitany-argument1-any-argument2)
* * *
### `connect()`
- Parameters
- listener — Function
- context — Any — optional
Adds the given listener function into the signal listeners.
By default, the signal function works like this method.
```javascript
var obj = {};
signal.create(obj, 'onPress');
obj.onPress(function(){
console.log('listener 1');
});
obj.onPress.connect(function(){
console.log('listener 2');
});
obj.onPress.emit()
// listener 1
// listener 2
```
The given context will be used as a context in listener calling.
By default, the listener is called with the object on which the signal is created.
```javascript
var obj = {standard: true};
signal.create(obj, 'onPress');
var fakeContext = {fake: true};
obj.onPress(function(){
console.log(this);
}, fakeContext);
obj.onPress(function(){
console.log(this);
});
obj.onPress.emit();
// {fake: true}
// {standard: true}
```
> [`Source`](https://github.com/Neft-io/neft/blob/f9c128ccb37aa79380c961e878cd76ec9e79c99e/src/signal/index.litcoffee#signalconnectfunction-listener-any-context)
* * *
### `disconnect()`
- Parameters
- listener — Function
- context — Any — optional
Returns the given listener function from the signal listeners.
```javascript
var obj = {};
signal.create(obj, 'onPress');
var listener = function(){
console.log('listener called!');
};
obj.onPress.connect(listener);
obj.onPress.disconnect(listener);
obj.onPress.emit()
// no loggs...
```
> [`Source`](https://github.com/Neft-io/neft/blob/f9c128ccb37aa79380c961e878cd76ec9e79c99e/src/signal/index.litcoffee#signaldisconnectfunction-listener-any-context)
* * *
### `disconnectAll()`
Removes all the signal listeners.
> [`Source`](https://github.com/Neft-io/neft/blob/f9c128ccb37aa79380c961e878cd76ec9e79c99e/src/signal/index.litcoffee#signaldisconnectall)