API usage

A general description and demonstration of each of the APIs used in the game are given in the following sections. For an explanation of how each piece of functionality was incorporated into the final game, look at the code section. For the complete source code for this game, check out the book's page from Packt Publishing's website.

Web messaging

Web messaging allows us to communicate with other HTML document instances, even if they're not in the same domain. For example, suppose our snake game, hosted at http://snake.fun-html5-games.com, is embedded into a social website through iframe (let's say this social website is hosted at http://www.awesome-html5-games.net). When the player achieves a new high score, we want to post that data from the snake game directly into the host page (the page with iframe from which the game is loaded). With the web messaging API, this can be done natively, without the need for any server-side scripting whatsoever.

Before web messaging, documents were...