XML Parsing on the fly

[topus]

I found many libraries that parsing XML files but all of this use a standard approacing. Read the entire file in memory and parsing the tree. This is very expensive if the file is very big or if you lock far a minimal set of informations (for intance, suppose to check if in a 50Mb XML file exist a reference to a user "Donal Duck" ecc). Any people know a "parsing on the fly" library or class that parse a XML file but don't load the entire file in memory? Thanks in advance and sorry for the poor english

[kakan]

Use the SAX API. The samples/libraries you have been looking at appearantly uses DOM. Kakan

[lemur2]

To be more specific, you want to find a parser that *supports* the SAX API. It isn't SAX exactly, but James Clark's expat supports a similar interface and is one of the earliest and IMO still one of the best XML parsers around. It's certainly very easy to use. You can get this on sourceforge. Kev

[Prakash Nadar]

I think MSXML supports both SAX and DOM way of parseing the xml file. It would be good thing to use unless you dont want to use COM in your application.

---

-Prakash

[kakan]

lemur2 wrote:

To be more specific, you want to find a parser that *supports* the SAX API.

Well... It's pretty hard to to use the SAX API (as I suggested), if the parser in question doesn't support it :laugh:

[kakan]

Yes, it does.

[Prakash Nadar]

kakan wrote:

Yes, it does.

thanx :->:->

---

-Prakash

[lemur2]

kakan wrote:

Well... It's pretty hard to to use the SAX API (as I suggested), if the parser in question doesn't support it

Oops, sorry - slipped into work document-reviewing-mode. Comment still stands though ;) K

[topus]

I looking for a library working like: ParseXMLFile(file...,callback ) { while( scanning file...){ ..... callback.OnEnterNode( nodeName, attributes...) .... .. processing XML formatting... .... callback.OnExitNode( nodeName ) } }

[kakan]

That's what (a parser with a) SAX-api does! You register callbacks for the events you are interested of. Then you call the parse() function in the parser, and it calls your callback functions when appropriate. And it does this "on the fly", that is: while it's reading the XML file. So it's exacly what you want! You might be interested in checking MSXML out. It has got a SAX API. There are heaps of samples how to use SAX on MSXML. Kakan