CODEWITHSUNDEEP
javascript
Lane Lourcey
Lane Lourcey

Reputation: 21

Take array of values and defined function and generate an array of functions with each containing the respective values

I'm looking for a way to take an array of values, and generate an array of functions with the argument of said function being populated by each initial array item. For example...

const IDs = [001, 002, 003]
const getEmpData = (id) => { fetch(`companysite.com/data/user eq '${id}'`) }
// Code to generate below array
[
  fetch(`companysite.com/data/user eq '001'`),
  fetch(`companysite.com/data/user eq '002'`),
  fetch(`companysite.com/data/user eq '003'`)
]

This is a very simplified version of a problem I'm trying to solve, which may not even be the ideal thing to do - but I was curious if this was an actual pattern. I would take the resulting array, chunk it, and then put it into a reduce method to make batches of API requests.

Upvotes: 2

Views: 41

Answers (2)

AKX
AKX

Reputation: 168913

If you don't actually need code but just an array of functions, you can use Function.bind:

const IDs = [001, 002, 003];
const getEmpData = (id) => fetch(`companysite.com/data/user eq '${id}'`);
const getters = IDs.map(id => getEmpData.bind(null, id);

Now getters will be an array of functions that accept no arguments and return the fetch promise.

And if what you actually need is an array of promises you want to resolve to results, you can use Promise.all(IDs.map(getEmpData))...

Upvotes: 0

Harsh Gundecha
Harsh Gundecha

Reputation: 1197

  • replace the console.log in below to required function

const IDs = [001, 002, 003]
// returns a function which can be invoked lazily when needed
const getFunction = (someData) => () => console.log(someData);
// the array of functions for all `IDs`
const functions = IDs.map(x => getFunction(x));
// optionally running all the `functions`
//    replace forEach with `map` if you wish to collect the resultant array from the function invocations
functions.forEach(functionToRun => functionToRun());

Upvotes: 1

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