Creating an SMS group forwarder in Twilio with NodeJS

Question

Here's what I'm trying to accomplish:

Set a list of names and numbers (my "group")
When a text message is sent to the Twilio number, forward it on to every member in the group

At a high-level, the idea seems straight forward enough. My programming / syntax skills are rusty, though, and I'd love some help.

I'm using Twilio Functions, and I've been able to send and receive messages successfully. Now I am stuck on how to carry this idea of iterating through a group.

Here's what I've written so far:

var groupmembers = {

    jonathan:{
        name: 'Jonathan',
        number: '+0000000000'
    },
    joshua:{
        name: 'Joshua',
        number: '+1110000000'
    }

}

exports.handler = function(context, event, callback) {

  // Set some values for later use
  this.fromNumber = event.From
  this.body = event.Body || ''

  let twiml = new Twilio.twiml.MessagingResponse();

  groupmembers.forEach(function(member) {

    // Skip sending if it's the same number
    if (member.number === this.fromNumber ) {
        return;
    }

    // Otherwise, let's send a mesage!
    twiml.message("Hello World").to( member.number );

    callback(null, twiml);
  });

};

The issues I believe I have:

Not being sure how to properly set my array or "dictionary"
Not knowing the proper syntax for passing the "to" variable to the message
Not knowing the proper syntax for doing a loop in NodeJS (the Functions console is telling me that 'groupmembers.forEach is not a function')

Thank you for any and all feedback and for pointing me in the right direction!

score 3 · Answer 1 · answered Dec 30 '17 at 01:03

The mistake you have is pretty simple. groupmembers is an object, you want an array.

You may want something akin to this instead:

var groupmembers = [{
        name: 'Jonathan',
        number: '+0000000000'
    },
    {
        name: 'Joshua',
        number: '+1110000000'
    }]

Apart from that, it looks to me as okay.

score 3 · Answer 2 · answered Dec 30 '17 at 07:56

With more searching and the point in the right direction from Slava I was able to figure it out! Here's the complete code:

/**
 * Represents a search trough an array.
 * @function search
 * @param {Array} array - The array you wanna search trough
 * @param {string} key - The key to search for
 * @param {string} [prop] - The property name to find it in
 * Props: https://stackoverflow.com/a/33097318/315818
 */

function search(array, key, prop){
    // Optional, but fallback to key['name'] if not selected
    prop = (typeof prop === 'undefined') ? 'name' : prop;    

    for (var i=0; i < array.length; i++) {
        if (array[i][prop] === key) {
            return array[i];
        }
    }
}

var groupmembers = [
    {
        name: 'Jonathan',
        number: '+000000000'
    },
    {
        name: 'Joshua',
        number: '+111111111'
    }
];

exports.handler = function(context, event, callback) {

  let twiml = new Twilio.twiml.MessagingResponse();

  // Search for the group member that matches the sender number
  let sender = search(groupmembers, event.From, 'number');

  // Now, loop through each of the group members
  groupmembers.forEach(function(member) {

    // Skip sending if it's the same number
    if (member.number === event.From ) {
        return;
    }

    // Now, forward on the message to the group member, using the sender's name 
    twiml.message(`${sender.name}: ${event.Body}`, {
        to: member.number
    });

  });
  // Loop ended 

  callback(null, twiml);

};

Creating an SMS group forwarder in Twilio with NodeJS

2 Answers2