Web background service on labs

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The Web Background service enables web applications to run partly in the background, even when the browser is not running. The part of the JavaScript code that is executed in the background can use APIs such as XMLHttpRequest to communicate over the network and Web Notifications to get the user's attention.

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Web background service on labs

  1. 1. Web Background Service A labs.ericsson.com enabler https://labs.ericsson.com/apis/web-background-service/
  2. 2. 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 2
  3. 3. Web Background features The background JavaScript code can use APIs 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 3
  4. 4. Web Background example Simple banana counting script running in 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 4
  5. 5. 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> 5
  6. 6. 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); }; 6
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