Parsing large XML files in Adobe Flex

Question

I am working on an Adobe Flex app, which needs to parse a relativley large XML file. ATM it is only 35MB, but in an ideal world would get much larger in the future. **Edit: I have no control over the XML file

I am essentially dropping it's contents right into an SQLITE database, so I could use the SimpleXML class to turn it into an object and then iterate through it, but I am worried that this would be a bad approach as the file gets larger. Am I being paranoid, or is there a better way of doing this?

Answer 1

You will definitely run into some performance issues parsing an XML file that large. Back in Flex 2 days we used SOAP for services and had one data call that pulled back about 5K records and the Flash Player would hang / browser go unresponsive for about 10 seconds on a reasonably fast machine. I can't remember the size of that SOAP message but it couldn't have been more than 1-2 MB.

If it's possible for your backend to transform the XML into an object graph and send it back over AMF you will see much better performance. Flash Player does really well with large datasets provided they're encoded in AMF (condensed binary format).

Even stil, I'd really consider whether you want to send a single result that large of break it up into pieces. At least that way you have a path for better scaling and can give the user some better feedback, i.e. displaying a message such as "Processing Item 6 of 35..."