feat(core): Intent to ship instance property (#315)

Implement a property of array containing instances generated in a page

Fix #308
Close #315

spec/internals/bb-spec.js

@@ -27,6 +27,12 @@ describe("Interface & initialization", () => {
 		expect(d3.select(chart.element).classed("bb")).to.be.true;
 		expect(internal.svg.node().tagName).to.be.equal("svg");
 		expect(internal.convertInputType()).to.be.equal(internal.inputType);
+
+		expect(chart).to.be.equal(bb.instance[0]);
+	});
+
+	it("should return version string", () => {
+		expect(bb.version.length > 0).to.be.ok;
 	});
 
 	it("should resize correctly in flex container", done => {

src/core.js

@@ -48,8 +48,28 @@ const bb = {
 	 *  chart.data("data1");
 	 */
 	generate(config) {
-		return new Chart(config);
+		const inst = new Chart(config);
+
+		this.instance.push(inst);
+
+		return inst;
 	},
+	/**
+	 * An array containing instance created
+	 * @property {Array} instance instance array
+	 * @example
+	 *  // generate charts
+	 *  var chart1 = bb.generate(...);
+	 *  var chart2 = bb.generate(...);
+	 *
+	 *  bb.instance;  // [ chart1, chart2, ... ]
+	 * @memberOf bb
+	 */
+	instance: [],
+	/**
+	 * Internal chart object
+	 * @private
+	 */
 	chart: {
 		fn: Chart.prototype,
 		internal: {

src/internals/ChartInternal.js

@@ -1,6 +1,7 @@
 /**
  * Copyright (c) 2017 NAVER Corp.
  * billboard.js project is licensed under the MIT license
+ * @ignore
  */
 import {
 	timeParse as d3TimeParse,