offline support with web control v8 RRS feed

  • Question

  • What is the status for using v8 web control offline?  I'm working on an app that will track boats out of cell range and should work on your average smart phone with no satcom capability.  



    Wednesday, August 3, 2016 1:18 AM


  • V8 can't work offline and there are no plans to support this at this time. We did look into this early on when planning the V8 control but found that web apps are severely limited when it comes to offline. Primarily that there is a lot of storage opens but not one good one that works everywhere, storage limits and browser support. Realistically, to support offline and have a good offering to make this feature worth the investment, at least 50MB of storage would be needed, by closer to 150MB - 500MB would be preferred. For example:

    • LocalStorage on mobile has a storage limit from 2MB to 10MB depending on mobile browser.
    • IndexedDB is only supported in some mobile browser and has a storage limit from 5MB to roughly 20% of available disk space depending on browser.
    • WebSQL, deprecated API.
    • Application Cache, not really an option due to the massive number of files that would be needed. To cover a just a few city blocks with a couple of zoom levels the number of map tiles is very large. The config file for app cache would end up being too large for the browser to handle. I actually tested this out and the browser just crashed. Also, some browsers have storage limits that are too low.
    • File System, few browsers have any way to access the file system.
    • Session Storage, limits range from 5MB to large, depending on browser.

    In addition to storage limits there are also read/write performance to consider which can rule out a few of these options as well.

    Bing Maps V8 is also highly dynamic. The more features you use the more of scripts that are loaded to provide the needed functionality. Many of these are not loaded until needed. For instance, if you load the map and initially only show pushpins, minimal logic will exist for the polygon class until you create a polygon instance, at which point the required supporting logic will be downloaded. This is done to keep the page light and fast.

    All this said, we will likely reinvestigate this feature again at a later date.

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    Wednesday, August 3, 2016 1:54 AM