Smartphone Development Page 3 - Advanced BlackBerry Browser Development |
Applications developers create can now push content directly to the BlackBerry browser cache. This advanced feature will prove to be particularly helpful, as it allows users to access pages from a local cache at any time, even when they’re well outside of the wireless coverage area. Cache push content can now also be associated with a specific channel. If you specify a channel identifier, the content URL will be added to the appropriate channel. If you don’t specify a channel identifier, the content will be added to the persistent cache. The user will have no idea that this content has been updated, but the next time they visit the specified URL, the BlackBerry browser can retrieve the content from the cache. Developers can now create applications that push data to the browser cache with what can only be described as an expiration date. Developers can increase or decrease the amount of time the cache memory stores content simply by including a date and time in the “expires” header in the push requests HTTP header. Like most BlackBerry technology, Push is easy to use and even easier to take full advantage of. When you begin to develop push apps, you should consider the types of information your users might need pushed to them and then determine how often you should push that information. You should also consider having your users subscribe to the push information they require the most, which will enable them to manage their own subscriptions. When you begin to design a push application, just keep in mind that it requires that you create a URL for the location you will post the data, create the content for the push app, and identify the addresses of those you want to send the message to. Anything beyond that is entirely up to you and your imagination.
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