Developers
AvantGo Channel Developer Guide

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Pages are returned in upredictable order

Pages from your channel site are returned to the AvantGo sync server in a generally unpredictable order. As a consequence, you must ensure that all the pages that you want downloaded in your channel fit within your Maximum Channel Size setting.

Why? If your channel content within the set Link Depth exceeds your Maximum Channel Size setting, you cannot predict which pages or graphics will fail to download. And the exact combination of pages and graphics that fails to download can change every time you sync, because you never know what pages the AvantGo sync server will receive first before your channel reaches its maximum size.

For example, in a site like the following...

Figure 4-2 Hypothetical channel website structure

The AvantGo sync server will grab page A, and then make requests for page B and Z. After that, it all depends on what comes back first. If page Z comes back first, we will request pages Y and X before requesting C and D. But if B comes back first, we will request pages C and D next. (And heck, we may end up grabbing pages E and F before we even get page Z back.). Pretty much the only thing you can guarantee is that you will receive a page before any of its children (that is, you will receive page B before C, D, E, and F, assuming no other pages link to them.)



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