Date post: | 25-May-2015 |
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Education |
Upload: | tor-bjoern-minde |
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Web Background Service
A labs.ericsson.com enablerhttps://labs.ericsson.com/apis/web-background-service/
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Web Background service
A stand-alone Java application that runs on Android as well as on platforms supporting Java Standard Edition
Enables web applications, running in the browser, to run part of the application logic in the background
The JavaScript code running in the background will continue to run when the associated web application running in the browser is closed
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Web Background features
The background JavaScript code can useAPIs such as XMLHttpRequest to communicate over the network and Web Notifications to get the user's attention
Remote Procedure Call (RPC) bridge allows for simple interaction between the main application and the background code
Management Console lets the user manage currently running background applications
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Web Background example
Simple banana counting script runningin the Web Background service
The background script updates the web page with the current banana count using RPC
When the web application running in the browser is closed, notifications are used to alert the user
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Web Background example
Web application running in the browser<html><head><title>Simple Web Background application</title><script src="wb.js"></script> <!– bootstrap script --><script>wb.onload = function () {
wb.enable("icon.png", document.title, "Here's the description", "persistent.js");
};
function log(msg) {document.body.innerHTML += msg + "<br>";
}</script></head><body></body></html>
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Web Background example
persistent.js (running in the WB service)var count = 0;var notification;wb.client.importFunctions("log");
wb.client.onconnect = function () {setInterval(function() {
var msg = "number of bananas: " + count++;if (wb.client.connected)
wb.client.log(msg);else {
if (notification)notification.cancel();
notification = notifications.createNotification("icon.png",”Banana count", msg);
notification.show();}
}, 3000);};
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