Question

I plan to use XML/XSLT in my iPhone application.

What version of XSLT is currently supported on the iPhone? Can I use XSLT 2.0 or just 1.0 ?

Answer 1

Using libxslt on the iPhone OS is actually quite easy:

1. Download the source-code of libxslt and extract it.
2. Add the “libxslt” dir to Header search paths in your build settings. Also, add the path to the libxml-headers there (usually /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS3.0.sdk/usr/include/libxml2).
3. Add libxml2.2.dylib and libxslt.dylib to the linked frameworks (Xcode “Groups & Files” panel: right click on “Frameworks” –> “Add” –> “Existing Frameworks…”).
4. Create a simple XML file and its XSL tranformation.

And finally you can use a code similar to the sample above to get the tranformation result into an NSString (e.g. to display in in a UIWebView):

#import <libxml/xmlmemory.h>
#import <libxml/debugXML.h>
#import <libxml/HTMLtree.h>
#import <libxml/xmlIO.h>
#import <libxml/xinclude.h>
#import <libxml/catalog.h>
#import <libxslt/xslt.h>
#import <libxslt/xsltInternals.h>
#import <libxslt/transform.h>
#import <libxslt/xsltutils.h>

...

NSString* filePath = [[NSBundle mainBundle] pathForResource: @"article" ofType: @"xml"];
NSString* styleSheetPath = [[NSBundle mainBundle] pathForResource: @"article_transform" ofType:@"xml"];

xmlDocPtr doc, res;

// tells the libxml2 parser to substitute entities as it parses your file
xmlSubstituteEntitiesDefault(1);
// This tells libxml to load external entity subsets
xmlLoadExtDtdDefaultValue = 1;

sty = xsltParseStylesheetFile((const xmlChar *)[styleSheetPath cStringUsingEncoding: NSUTF8StringEncoding]);
doc = xmlParseFile([filePath cStringUsingEncoding: NSUTF8StringEncoding]);
res = xsltApplyStylesheet(sty, doc, NULL);

char* xmlResultBuffer = nil;
int length = 0;

xsltSaveResultToString(&xmlResultBuffer, &length, res, sty);

NSString* result = [NSString stringWithCString: xmlResultBuffer encoding: NSUTF8StringEncoding];

NSLog(@"Result: %@", result);

free(xmlResultBuffer);

xsltFreeStylesheet(sty);
xmlFreeDoc(res);
xmlFreeDoc(doc);

xsltCleanupGlobals();
xmlCleanupParser();