From: Marc-Aurèle DARCHE <ma.darche@cynode.org>
Date: Sat, 6 Feb 2016 18:57:21 +0000 (+0100)
Subject: Document different techniques to share objects
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=fa734d7824ae9bf1bae7fe0fad2e35fde40b1406;p=platform%2Fframework%2Fweb%2Fcrosswalk-tizen.git

Document different techniques to share objects

This has been discussed in
---

diff --git a/docs/faq/electron-faq.md b/docs/faq/electron-faq.md
index 643bde7..d5470f7 100644
--- a/docs/faq/electron-faq.md
+++ b/docs/faq/electron-faq.md
@@ -18,6 +18,40 @@ New features of Node.js are usually brought by V8 upgrades, since Electron is
 using the V8 shipped by Chrome browser, the shiny new JavaScript feature of a
 new Node.js version is usually already in Electron.
 
+## What are the different techniques to share objects between web pages?
+
+To share objects between web pages (that is on the renderer side) the simplest
+and more natural technique is to use a web standard API already available in all
+browsers. A good candidate is the
+[Storage API](https://developer.mozilla.org/en-US/docs/Web/API/Storage),
+through either the
+[`window.localStorage`](https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage) property or the
+[`window.sessionStorage`](https://developer.mozilla.org/en-US/docs/Web/API/Window/sessionStorage) property.
+Note that the Storage API allows only to store strings, so objects must be
+serialized as JSON.
+Another candidate is
+[IndexedDB](https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API).
+
+Another technique, but this time specific to Electron, is to store objects in
+the main process as a global variable and then to access them from the renderers
+through the `remote` module:
+
+```javascript
+// In main.js of browser process
+global.sharedObject = {};
+```
+
+```javascript
+// js in page-1.html
+require('remote').getGlobal('sharedObject').someProperty = 'some value';
+```
+
+```javascript
+// js in page-2.html
+console.log(require('remote').getGlobal('sharedObject').someProperty);
+```
+
+
 ## My app's window/tray disappeared after a few minutes.
 
 This happens when the variable which is used to store the window/tray gets
diff --git a/docs/tutorial/quick-start.md b/docs/tutorial/quick-start.md
index ebf907e..ccb3836 100644
--- a/docs/tutorial/quick-start.md
+++ b/docs/tutorial/quick-start.md
@@ -47,6 +47,9 @@ In Electron, we have provided the [ipc](../api/ipc-renderer.md) module for
 communication between the main process and renderer process. There is also a
 [remote](../api/remote.md) module for RPC style communication.
 
+And finally there are different techniques [to share objects between web
+pages](../faq/electron-faq.md#) of the same window or of different windows.
+
 ## Write your First Electron App
 
 Generally, an Electron app is structured like this: