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Identifiers
Identify a listener function call based on its call stack 🕵️
A listener identifier is an array of strings representing the current call stack in reverse chronological order (newest first).
Listener functions receive a listener identifier (
lid) as the first argument.Here we show how listener functions pass the
lid along to the next listener function.① Create a library with listeners that call each other and save it as
lidExample.ts:lidExample.ts
class LidExample {
public a(lid: string[]) {
console.log(lid)
this.b(lid)
}
public b(lid: string[]) {
console.log(lid)
}
}
export default new LidExample()
The identifier array is immutable and remains the same value for the scope of the function.
② Load the listener, call the listener function, and save it as
main.ts:main.ts
import listener from "@listener-js/listener"
import lidExample from "./lidExample"
listener.load([], { lidExample })
lidExample.a([])
③ Execute
main.ts and view the output:$ ts-node main.ts
["lidExample.a"]
["lidExample.b", "lidExample.a"]
Its not heresy to simply prepend your own id to the
lid as you pass it along:customIdExample.ts
class CustomIdExample {
public a(lid: string[]) {
this.b(["customId", ...lid])
}
public b(lid: string[]) {
console.log(lid)
// ["customIdExample.b", "customId"]
}
}
export default new CustomIdExample()
By changing
lid to lid_, we signal for listener to prepend a unique identifier to the listener function call:uniqueIdExample.ts
class UniqueIdExample {
public a(lid_: string[]) {
console.log(lid_[1]) // a, b, c...
}
}
export default new UniqueIdExample()
Unique identifier is a misnomer; the identifier is more like an alphanumeric counter that produces ids in the same order with each new execution.
Last modified 4yr ago