Tabris implements a subset of popular W3C standards. Besides providing web developers with familiar APIs, this also enables you to use libraries developed for a browser environment.
window in Tabris.js. For example, the tabris object can be accessed either via
As in the browser, messages can be logged to the developer console using the global
console.log("A log message"); console.error("An error Message"); console.warn("A warning message"); console.info("An info message"); console.debug("A debug Message");
console.error will also cause a message to pop up (even if the developer console is closed), but it won’t interrupt script execution. See Console.
Tabris supports the timer methods
clearInterval. See timer.
Blobs represent raw data that may be created from various sources and can also be read into an
ArrayBuffer or converted to a string. They are accepted by fetch, XMLHttpRequest, FileSystem and WebSocket APIs.
Tabris supports the
XMLHttpRequest to make HTTP request and to read resources that are part of the application.
- Only asynchronous requests are supported. Attempting a synchronous request will cause an error.
- When a relative URL is given, Tabris.js will interpret it as a path relative to the application’s
package.json. This allows you to read static resources (files residing in your project folder).
- When using a custom built developer client, a relative URL may be used to access local files (bundled with the client as a resource) as well as those residing in the remote project folder (from which the code is loaded via HTTP). Local files take precedence.
- To enable access to SSL protected resources that use self signed certificates, use the
UseStrictSSLpreference in the config.xml. See Building a Tabris.js App.
As a more powerful and flexible alternative to XHR, you can also use the Fetch API. As of Tabris.js 1.7, an implementation of this API is included.
To load static resources, working with URLs relative to the current module may be more convenient. In the case of a JSON file, this can be done simply by using the
requiremethod instead of XHR. For other types of files, use the
xhr.open("GET", __dirname + "/foo.txt");.
WebSockets are an advanced technology that makes it possible to open an interactive communication session between the user’s client and a server. With this API, you can send messages to a server and receive event-driven responses without having to poll the server for a reply.
As of Tabris.js 1.10, an implementation of this API is included.
The Tabris.js implementation supports to send and receive text messages as well as binary data in the form of
ArrayBuffer. We currently do not support to receive data as
Tabris supports the global object
localStorage, which allows storing key-value pairs in a persistent store. Both keys and values are stored as strings.
On iOS, there is an additional object
secureStorage available in the global scope. This is a drop-in replacement for
localStorage that keeps data in the encrypted iOS Keychain.
secureStoragesupport the methods
sessionStorageis not supported, as it would serve no purpose in a non-browser environment.
- The storage event is currently not supported.
localStorageis only meant to store relatively short strings. To store larger amounts of data it is recommended to use the cordova
Canvas widget provides an HTML5 canvas compatible “2D Context” object. See Canvas.
Random Source (Crypto)
The global object
crypto provides an implementation of the RandomSource interface. It can be used to generate cryptographically secure random numbers.