global: add external event listener

* Adds an event listener so a search can be triggered externally.
* Removes `historyListen` prop which is redundant now.

docs/docs/components/react_search_kit.md

@@ -48,7 +48,10 @@ See the [complete guide](main_concepts.md) for detailed information.
 
   A boolean to define a default `sort by` value when the query string is empty. This is useful when the results sorting should be different when the user inserts a query string or not (e.g. `most recent` or `most relevant` first).
 
-* **history** `object` *optional*
+* **appName** `string` *optional*
 
-  The [React Router history](https://github.com/ReactTraining/history) object to add a new listener to the browser history to perform searches on URL parameters changed.
+  A name identifier to distinguish uniquely the application. Default `RSK`.
 
+* **eventListenerEnabled** `boolean` *optional*
+
+  If `true` the application listens to the `queryChanged` event else if `false` no listener is registered. When this event is emitted the application triggers a search based on the payload that is passed to the event at the emission time. Default `false`.

docs/docs/main_concepts.md

@@ -106,6 +106,66 @@ The concept around `SearchAPI` and `UrlHandlerApi` will be explained more in det
 
 ---
 
+---
+
+## Events
+
+You can control the app state externally using available events in `React-SearchKit`:
+
+* `queryChanged`: `React-SearchKit` listens to this event and updates the `query` state based on the payload of the event. `React-SearchKit` will ignore any field that is passed and is not part of the store's keys.
+
+> Note: By default `React-SearchKit` is not registering any event. To enable this behaviour you need to pass in the root component the below variable:
+
+```jsx
+class MyReactSearchKit extends Component {
+  render() {
+    return (
+      <ReactSearchKit {...this.props} eventListenerEnabled={true}>
+        {this.props.children}
+      </ReactSearchKit>
+    );
+  }
+}
+```
+
+In order to trigger the `queryChanged` event you can use the `onQueryChanged` emitter function that is part the `React-SearchKit` library. For example:
+
+
+```jsx
+import { onQueryChanged } from 'react-searchkit';
+
+class MyExternalApp extends Component {
+    render() {
+        return (
+        <Button onClick={() => onQueryChanged({queryString: 'search'})}>Trigger Search</Button>
+        );
+    }
+}
+
+class MyReactSearchKit extends Component {
+  render() {
+    return (
+      <ReactSearchKit {...requiredProps} searchOnInit={false} eventListenerEnabled={true}>
+        {this.props.children}
+      </ReactSearchKit>
+    );
+  }
+}
+
+class MyApp extends Component {
+    render() {
+        return (
+            <>
+                <MyExternalApp />
+                <MyReactSearchKit />
+            </>
+        )
+    }
+}
+```
+
+---
+
 ## TL;DR
 
 * UI Components change the `query` state through Redux actions in response to user inputs. They receive the updated `results` state after a REST APIs search through props injected automatically by Redux.

docs/docs/using_url_parameters.md

@@ -168,42 +168,6 @@ const myUrlParamsHandler = new MyUrlParamsHandler();
 
 ---
 
-## React Router history integration
-
-React-SearchKit can integrate with [React Router history](https://github.com/ReactTraining/history) library. This is useful when any React component in your app (external to React-SearchKit) changes URL search parameters and you expect that a search is triggered.
-
-For example, if a component changes the query parameters to `?q=react`, then a new search with the query string value `react` should be triggered.
-
-To achieve this, you can inject the `history` object to the main `<ReactSearchKit>` component. A new listener will be automatically added and from now on any change to the URL parameters will trigger a search.
-
-> React-SearchKit will **not** listen to changes to `window.location` object. You will have to use `React Router history` in your app and inject it in React-SearchKit.
-
-```jsx
-import React, { Component } from 'react';
-import { createBrowserHistory } from 'history';
-import { ReactSearchKit, InvenioSearchApi } from 'react-searchkit';
-
-const history = createBrowserHistory();
-
-const searchApi = new InvenioSearchApi({
-  url: 'https://zenodo.org/api/records/',
-  timeout: 5000,
-  headers: { Accept: 'application/vnd.zenodo.v1+json' },
-});
-
-class App extends Component {
-  render() {
-    return (
-      <ReactSearchKit searchApi={searchApi} history={history}>
-        <h1>My search UI</h1>
-      </ReactSearchKit>
-    );
-  }
-}
-```
-
----
-
 ## TL;DR
 
 * You can enabled or disable deep linking with a flag