Offline differences

The majority of mobile device users are currently operating in an offline mode, without a wireless connection. These users periodically doc and synchronize their mobile devices with a desktop PC that has an Internet connection, then they work offline for extended periods of time. Even those users who do have a wireless connection generally tend to connect only periodically to synchronize, and then disconnect and work offline.

  • Offline browsing – Relatively few mobile device users currently have a wireless connection, and many of those who do just connect through modem, synchronize their devices, and then disconnect and work offline.

    This means that you must design a fairly tight chunk of pages to download with the home page. You determine which pages are downloaded from your site when a user synchronizes your channel by specifying a setting for Link Depth—the number of links from your home page within which your pages are to be downloaded.

    You can also specify whether pages within that link depth, but outside of your Web site, are to be downloaded in a synchronization. Also, it is very important to avoid links to outside pages that are not optimized for mobile devices.

    If you don't plan carefully, important pages may not be downloaded—either because they are beyond the Link Depth, or because the total size of pages exceeds the maximum size set for your channel. See Size limit issues.

  • Offline form submissions – You must ensure that any forms used in your channel Web site do not require the user to wait for a response from the server after the form is submitted. Forms submitted offline are queued for submission to the server in the next synchronization. If it is absolutely necessary, you can prevent an offline user from submitting the same form again before synchronizing and getting back the server's response page.

    In addition, you will probably want to set up special handling of form submissions to ensure that the user understands what has happened to the submitted form and can easily find the response page after synchronizing. See Managing Channel Form Submissions.