Signal class
Signal is used to hold the data. Signal is immutable, each modification will generate a new signal instance.
Properties
Signal.id
String, the id of the signal, the id represents the origin of the signal. All the variations from this signal will share the same id.
Signal.seq
String, alias of Signal.id
Signal.payload
Object, the payload data
Signal.anonPayload
Primitive type, the anonymous payload. When you pass a primitive type in the signal's constructor, it will be stored in the anonymous payload
Signal.error
Error type, the error represented by the signal, if there is any.
Signal.end
Boolean, if it it and end signal. (For back pressure)
Methods
constructor(payload)
Arguments
| Arguement | Type | Description |
|---|---|---|
| payload | any | the payload object |
Note: you don't need to create a signal by your own. Usually, you use node's
sendorpushmethod directly with the payload itself. These method will construct a signal for you.
create signal with constructor
const s1 = new Signal(1);
console.log(s1.payload); // --> {__anon__: 1} anonymous payload, with value 1
const s2 = new Signal({v: 10});
console.log(s2.payload); // --> {v: 10}
Signal.new(payload)
create a new signal with new payload, but keep the signal id
Arguments
| Arguement | Type | Description |
|---|---|---|
| payload | any | the payload object |
Return
| Type | Description |
|---|---|
| Signal | the new signal |
create new signal and keep the signal id
const s1 = new Signal({v: 1});
const s2 = s1.new({v: 2});
console.log(s1.payload); // --> {v:1}
console.log(s2.payload); // --> {v:2}
console.log(s1.id === s2.id); // true
Signal.get(key)
get value in the payload with a key
Arguments
| Arguement | Type | Description |
|---|---|---|
| key | String | the key of the value in payload |
Return
| Type | Description |
|---|---|
| any | the value or null |
get the payload with a key
const s1 = new Signal({v: 1});
console.log(s1.get('v')); // --> 1
Signal.set(key, value)
set the payload with a key, returns a new signal with the same id
Arguments
| Arguement | Type | Description |
|---|---|---|
| key | String | the key of the value in payload |
| value | any | the value |
Return
| Type | Description |
|---|---|
| Signal | the new signal |
get the payload with a key
const s1 = new Signal({v: 1});
const s2 = s1.set('k', 'this is a value');
console.log(s2.get('v')); // --> 1,
console.log(s2.get('k')); // --> this is a value
Signal.del(key)
del the payload with a key, returns a new signal with the same id
Arguments
| Arguement | Type | Description |
|---|---|---|
| key | String | the key of the value in payload |
Return
| Type | Description |
|---|---|
| Signal | the new signal |
get the payload with a key
const s1 = new Signal({v: 1, k: 'string value', j: true});
const s2 = s1.del('k');
console.log(s2.get('v')); // --> 1,
console.log(s2.get('k')); // --> null
Signal.getResult()
get the value of special field __result__. This special field in signal is used to store the processing result of an actuator.
The result value of actuator will be stored in this field.
Return
| Type | Description |
|---|---|
| any | the result or null |
get the payload with a key
const ns = collar.ns('test');
const input = ns.input('input');
input
.do(s => {
return 100;
})
.do(s => {
console.log(s.getResult()); // --> 100
});
input.push({}); // push any input signal through input node