Resolve issue #4.

If there is no container, toast will be enqueue and dispatched as soon as an
container is available

src/ToastContainer.js

@@ -71,9 +71,11 @@ class ToastContainer extends Component {
   }
 
   componentDidMount() {
-    EventManager.on(config.ACTION.SHOW,
+    EventManager
+      .on(config.ACTION.SHOW,
       (content, options) => this.show(content, options))
-      .on(config.ACTION.CLEAR, () => this.clear());
+      .on(config.ACTION.CLEAR, () => this.clear())
+      .emit(config.ACTION.MOUNTED);
   }
 
   componentWillUnmount() {

src/__tests__/ToastContainer.js

@@ -49,6 +49,7 @@ describe('ToastContainer', () => {
     // Create a toast
     toastify('coucou');
     const props = component.children().find(Toast).props();
+
     [
       'autoClose',
       'closeButton',

src/__tests__/toastify.js

@@ -0,0 +1,21 @@
+/* eslint-env jest */
+
+import React from 'react';
+import { mount } from 'enzyme';
+
+import ToastContainer from './../ToastContainer';
+import toastify from './../toastify';
+import EventManager from './../util/EventManager';
+import config from './../config';
+
+describe('toastify', () => {
+  it("Should emit notification only if a container is mounted", () => {
+    const spy = jest.fn();
+    EventManager.on(config.ACTION.SHOW, spy);
+    toastify('hello');
+    expect(spy).not.toHaveBeenCalled();
+
+    mount(<ToastContainer />);
+    expect(spy).toHaveBeenCalled();
+  });
+});

src/config.js

@@ -16,6 +16,7 @@ export default {
   },
   ACTION: {
     SHOW: 'SHOW_TOAST',
-    CLEAR: 'CLEAR_TOAST'
+    CLEAR: 'CLEAR_TOAST',
+    MOUNTED: 'CONTAINER_MOUNTED'
   }
 };

src/toastify.js

@@ -20,7 +20,24 @@ function mergeOptions(options) {
   return Object.assign({}, defaultOptions, options);
 }
 
-const emitEvent = (content, options) => EventManager.emit(ACTION.SHOW, content, options);
+let isContainerMounted = false;
+let queue = [];
+
+EventManager.on(ACTION.MOUNTED, () => {
+  isContainerMounted = true;
+  queue.forEach(item => {
+    EventManager.emit(item.action, item.content, item.options);
+  });
+  queue = [];
+});
+
+const emitEvent = (content, options) => {
+  if (isContainerMounted) {
+    EventManager.emit(ACTION.SHOW, content, options);
+  } else {
+    queue.push({ action: ACTION.SHOW, content, options });
+  }
+};
 
 export default Object.assign(
   (content, options) => emitEvent(content, mergeOptions(options)),