Call a Function - React Native SDK

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Before You Begin

Call a Function

Realm is now Atlas Device SDK – Learn More

The examples in this section demonstrate calling a simple Atlas Function named sum that takes two arguments, adds them, and returns the result:

// sum: adds two numbers
exports = function(a, b) {
  return a + b;
};

Before You Begin

In an App Services App, define an Atlas Function.
In your client project, initialize the App client.
Then, authenticate a user in your React Native project.

Call a Function

Important

Make sure to sanitize client data to protect against code injection when using Functions.

To call a function, you can either pass its name and arguments to User.callFunction() or call the function as if it were a method on the User.functions property.

import React from 'react';
import {useUser} from '@realm/react';
function Addition() {
  // Get currently logged in user
  const user = useUser();
  const addNumbers = async (numA: number, numB: number) => {
    // Call Atlas Function
    // Method 1: call with User.callFunction()
    const sumMethod1 = await user?.callFunction('sum', numA, numB);
    // Method 2: Call with User.function.<Function name>()
    const sumMethod2 = await user?.functions.sum(numA, numB);
    // Both methods return the same result
    console.log(sumMethod1 === sumMethod2); // true
  };
  // ...
}

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