DataLayerHelper.js

/* Create helper using google/data-layer-helper from browser console */
var script   = document.createElement("script");
script.type  = "text/javascript";
script.text   = "(function(){var g=\/\\[object (Boolean|Number|String|Function|Array|Date|RegExp)\\]\/;function h(a){return null==a?String(a):(a=g.exec(Object.prototype.toString.call(Object(a))))?a[1].toLowerCase():\"object\"}function k(a,b){return Object.prototype.hasOwnProperty.call(Object(a),b)}function m(a){if(!a||\"object\"!=h(a)||a.nodeType||a==a.window)return!1;try{if(a.constructor&&!k(a,\"constructor\")&&!k(a.constructor.prototype,\"isPrototypeOf\"))return!1}catch(b){return!1}for(var c in a);return void 0===c||k(a,c)};function n(a,b,c){this.b=a;this.f=b||function(){};this.d=!1;this.a={};this.c=[];this.e=p(this);r(this,a,!c);var d=a.push,e=this;a.push=function(){var b=[].slice.call(arguments,0),c=d.apply(a,b);r(e,b);return c}}window.DataLayerHelper=n;n.prototype.get=function(a){var b=this.a;a=a.split(\".\");for(var c=0;c<a.length;c++){if(void 0===b[a[c]])return;b=b[a[c]]}return b};n.prototype.flatten=function(){this.b.splice(0,this.b.length);this.b[0]={};s(this.a,this.b[0])};function r(a,b,c){for(a.c.push.apply(a.c,b);!1===a.d&&0<a.c.length;){b=a.c.shift();if(\"array\"==h(b))a:{var d=b,e=a.a;if(\"string\"==h(d[0])){for(var f=d[0].split(\".\"),u=f.pop(),d=d.slice(1),l=0;l<f.length;l++){if(void 0===e[f[l]])break a;e=e[f[l]]}try{e[u].apply(e,d)}catch(v){}}}else if(\"function\"==typeof b)try{b.call(a.e)}catch(w){}else if(m(b))for(var q in b)s(t(q,b[q]),a.a);else continue;c||(a.d=!0,a.f(a.a,b),a.d=!1)}}function p(a){return{set:function(b,c){s(t(b,c),a.a)},get:function(b){return a.get(b)}}}function t(a,b){for(var c={},d=c,e=a.split(\".\"),f=0;f<e.length-1;f++)d=d[e[f]]={};d[e[e.length-1]]=b;return c}function s(a,b){for(var c in a)if(k(a,c)){var d=a[c];\"array\"==h(d)?(\"array\"==h(b[c])||(b[c]=[]),s(d,b[c])):m(d)?(m(b[c])||(b[c]={}),s(d,b[c])):b[c]=d}};})();";
document.body.appendChild(script);
var helper = new DataLayerHelper(dataLayer);

/* Get ecommerce dataLayer variable */
helper.get('ecommerce');

/* Get products array on product detail view pages from dataLayer */
helper.get('ecommerce.detail.products');

Copy lines 2-6 and paste them on your browser console to create a DataLayerHelper javascript object.