offline storage

[jpadie]

I am writing an ajax application that needs to work offline as well as online.

For this app to work offline i need to be able to store a whole bunch of parameters until the network connectivity is restored. This could amount to several 100kb and so cookies are not the best mechanism.

I know that i could develop this as an hta but i'd rather not because not all functionality will be ajax scripted.

has anyone come up with other good mechanisms for storing information on the local file system (without using java or flash)?

 

[BillyRayPreachersSon]

Could you store the data in a hidden textarea?

Hope this helps,
Dan



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[jpadie]

thanks for the thought. the offline data needs to be persistent (survive browser shut down/OS restart) - like a cookie but but without the size limitation.

 

[BillyRayPreachersSon]

Then without writing to the file system, you're pretty much out of luck.

Dan



Coedit Limited - Delivering standards compliant, accessible web solutions

[tt]Dan's Page [blue]@[/blue] Code Couch

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[jpadie]

and am i right in thinking that (outside an html application) javascript cannot write to the filesystem?

 

[Xaqte]

Take a look at this for some ideas:

http://ajaxian.com/archives/dojostorage-offline-access-and-permanent-client-side-storage

Let us know your results!

X

 

[jpadie]

Thanks.

I have used dojo for some stuff and took a look at it for this app i'm writing. I was uncomfortable with the size of the library and how supportable this would be on mobile devices (advanced pdas that support js). i was also uncomfortable about the use of flash as a storage engine but this was/is mainly due to my ignorance of all things flash.

but ... i think flash and hta (as alternatives) will be where I end up in all likelihood. which makes a stripped down version of dojo a contender (just have to work out how to strip it down...)

thanks again,
Justin

 

[theniteowl]

jpadie, you can access the local filesystem using ActiveX and the code would not really be much different than using an HTA file directly but of course this limits you to Internet Explorer and you would get ActiveX warning messages when the script executes.

Using HTA files locally on the client PC would prevent the ActiveX warnings from occuring but if you want it web based then you would have to be linking to the HTA file on the server which will cause it to download and execute from the client which again would cause ActiveX warnings.

You could build a custom control that would have to be registered on the client system and thereby allow access without warning messages but that seems it might be more complex than you want and I have no experience with it myself.



At my age I still learn something new every day, but I forget two others.

 

[Xaqte]

theniteowl,

you can also prevent the activeX warnings if you use the "mark of the web