Sending Some Traits to Some Tools But Not To Others!

index.js

// these are the trait keys you want to send to customer.io
var importantTraits = ['trait1', 'trait2', 'trait3'];

function identify(userId, traits) {
  traits = extend({}, traits || {});
  
  var matchingTraits = reduce(function(acc, val, key){
    if (~importantTraits.indexOf(key)) acc[key] = val;
    return acc;
  }, {}, traits);
  
  each(function(obj) {
    analytics.identify(userId, obj.traits, { integrations: obj.context }, function(){
      analytics.user().traits({});  
    })
  }, [
    {
      traits: traits,
      context: { "All": true, "Customer.io": false }
    },
    {
      traits: matchingTraits, 
      context: { "All": false, "Customer.io": true }
    }
  ]);
}

// @segmentio/extend
function extend(object /*, ...sources */) {
  var sources = Array.prototype.slice.call(arguments, 1);
  for (var i = 0, source; source = sources[i]; i++) {
      if (!source) continue;
      for (var property in source) {
          object[property] = source[property];
      }
  }
  return object;
}

// @ndhoule/foldl
function reduce(iterator, accumulator, collection) {
  each(function(val, key, collection) {
    accumulator = iterator(accumulator, val, key, collection);
  }, collection);
  return accumulator;
}

// @ndhoule/each
function each(iterator, object) {
  var ks = keys(object);
  for (var i = 0; i < ks.length; i += 1) {
    if (iterator(object[ks[i]], ks[i], object) === false) {
      break;
    }
  }
}

// @ndhoule/keys
function keys(object) {
  var results = [];
  for (var key in object) {
    if (Object.prototype.hasOwnProperty.call(object, key)) {
      results.push(String(key));
    }
  }
  return results;
}

usage.js

identify('123', { trait1: 'this will go through to customer.io', trait4: 'this wont!' });