Merge pull request #2 from CodingZeal/chores/documentation

Add installation and usage documentation to the README

Author: randycoulman

README.md

@@ -4,23 +4,63 @@
 [![CircleCI](https://circleci.com/gh/CodingZeal/redux-persist-sensitive-storage.svg?style=shield)](https://circleci.com/gh/CodingZeal/redux-persist-sensitive-storage)
 [![License](https://img.shields.io/badge/license-MIT-blue.svg)](https://opensource.org/licenses/MIT)
 
-redux-persist storage engine for react-native-sensitive-info
+Storage engine to use [react-native-sensitive-info](https://github.com/mCodex/react-native-sensitive-info) with [redux-persist](https://github.com/rt2zz/redux-persist).
 
-More details coming soon!
+react-native-sensitive-info manages all data stored in Android Shared Preferences and iOS Keychain.
 
-### TODO:
+**NOTE:** Android Shared Preferences are not secure, but there is [a branch of react-native-sensitive-info](https://github.com/mCodex/react-native-sensitive-info/tree/keystore) that uses the Android keystore instead of shared preferences.  You can use that branch with redux-persist-sensitive-storage if you prefer.
 
-- [ ] Write documentation
-  - [ ] How to install (react-native-sensitive-info needs to be installed and `react-native link`-ed)
-  - [ ] Example of how to use it
-  - [ ] Describe what options are (same ones accepted by react-native-sensitive-info)
-  - [ ] Mention that storage is not (yet) secure on Android, but point at branch on r-n-s-i that adds that.
-  - [ ] Contributing
+## Installation
 
-- [x] Add tests
+You can install this package using either `yarn` or `npm`.  You will also need to install and link [react-native-sensitive-info](https://github.com/mCodex/react-native-sensitive-info).
 
-- [ ] Test on both iOS and Android
+Using Yarn:
+```
+yarn add redux-persist-sensitive-storage react-native-sensitive-info
+react-native link react-native-sensitive-info
+```
 
-- [ ] Submit PR to add a link to this lib from redux-persist
+Using npm:
+```
+npm install --save redux-persist-sensitive-storage react-native-sensitive-info
+react-native link react-native-sensitive-info
+```
 
-- [ ] Submit PR to add a link to this lib from react-native-sensitive-info
+## Usage
+
+To use redux-persist-sensitive-storage, configure redux-persist according to [its documentation](https://github.com/rt2zz/redux-persist#redux-persist).
+
+Modify the `persistStore` call as follows:
+
+```js
+import createSensitiveStorage from "redux-persist-sensitive-storage";
+
+// ...
+
+persistStore(store, { storage: createSensitiveStorage(options) });
+```
+
+`options` is optional and are used to configure the keychain service (iOS) and shared preferences name (Android) that react-native-sensitive-info uses.  See [the documentation](https://github.com/mCodex/react-native-sensitive-info#methods) for more information.
+
+Here's a full example:
+
+```js
+import { compose, applyMiddleware, createStore } from "redux";
+import { persistStore, autoRehydrate } from "redux-persist";
+import createSensitiveStorage from "redux-persist-sensitive-storage";
+
+const store = createStore(
+  reducer,
+  compose(
+    applyMiddleware(...),
+    autoRehydrate()
+  )
+);
+
+persistStore(store, {
+  storage: createSensitiveStorage({
+    keychainService: "myKeychain",
+    sharedPreferencesName: "mySharedPrefs"
+  });
+);
+```