src/core/decorators/track.js
import trackEvent from "../events/track_event";
/**
* Use when you need to track a method call w/ the `trackEvent` utility.
* The value returned will be passed as `data` to `trackEvent`.
* If a function is used for the `trackingFn`, it must return an object w/ a `name`, and optional `data`
* @param {Function|String} trackingFn Either a function to build up the event data or a string event name.
* @param {Object} [options] An opject of options
* @param {Boolean} [options.sendReturnValue] Whether or not to send the return value as data
* @return {Function} The decorator function
* @example <caption>String Tracking</caption>
*
* class Foo {
* @track("Button Clicked")
* buttonClicked() {
* // ...
* return { some: "data" };
* }
* }
* @example <caption>Function</caption>
*
* import FooTracker from "./foo.tracker";
*
* class Foo {
* @track(FooTracker.clicked)
* buttonClicked() {
* // ...
* return { some: "data" };
* }
* }
*
* // foo.tracker.js
*
* export default function clicked(data) {
* // data = { some: "data" }
* data.otherData = "other data";
*
* return {
* name: "Button Clicked",
* data
* };
* }
* @example <caption>String Tracking w/ sendReturnValue false</caption>
*
* class Foo {
* @track("Button Clicked").sendReturnValue(false)
* buttonClicked() {
* // ...
* return { some: "data" };
* }
* }
*/
function track(trackingFn, options={ sendReturnValue: true }) {
let decorator = function(target, name, descriptor) {
const hasDescriptor = typeof descriptor.value !== "undefined";
const fn = hasDescriptor ? descriptor.value : target;
function trackDecorator() {
let fnReturnValue = fn.apply(this, arguments),
value = null;
if (options.sendReturnValue) {
value = fnReturnValue;
}
trackEvent(typeof trackingFn === "string" ?
Object.assign({ name: trackingFn, data: value }, options) :
trackingFn.apply(this, [value]));
return fnReturnValue;
};
if (hasDescriptor) {
descriptor.value = trackDecorator;
}
else {
target = trackDecorator;
}
};
decorator.sendReturnValue = function(value = true) {
options.sendReturnValue = !!value;
return this;
};
return decorator;
}
export default track;