XSD Validation on iOS

Question

I want to validate XML files against an XSD on iOS. The documentations alludes to using NSXMLDocument to do this, but its not available on iOS =(. Are there any light weight alternatives to do this on iOS?

JoeyJ · Accepted Answer · 2014-12-15T22:49:09.597

I ended up using the validation facilities in libxml2 since its a library already included in iOS. Following this sample code

#include <libxml/parser.h>
#include <libxml/xmlschemas.h>

int is_valid(const xmlDocPtr doc, const char *schema_filename)
{
    xmlDocPtr schema_doc = xmlReadFile(schema_filename, NULL, XML_PARSE_NONET);
    if (schema_doc == NULL) {
        /* the schema cannot be loaded or is not well-formed */
        return -1;
    }
    xmlSchemaParserCtxtPtr parser_ctxt = xmlSchemaNewDocParserCtxt(schema_doc);
    if (parser_ctxt == NULL) {
        /* unable to create a parser context for the schema */
        xmlFreeDoc(schema_doc);
        return -2;
    }
    xmlSchemaPtr schema = xmlSchemaParse(parser_ctxt);
    if (schema == NULL) {
        /* the schema itself is not valid */
        xmlSchemaFreeParserCtxt(parser_ctxt);
        xmlFreeDoc(schema_doc);
        return -3;
    }
    xmlSchemaValidCtxtPtr valid_ctxt = xmlSchemaNewValidCtxt(schema);
    if (valid_ctxt == NULL) {
        /* unable to create a validation context for the schema */
        xmlSchemaFree(schema);
        xmlSchemaFreeParserCtxt(parser_ctxt);
        xmlFreeDoc(schema_doc);
        return -4; 
    }
    int is_valid = (xmlSchemaValidateDoc(valid_ctxt, doc) == 0);
    xmlSchemaFreeValidCtxt(valid_ctxt);
    xmlSchemaFree(schema);
    xmlSchemaFreeParserCtxt(parser_ctxt);
    xmlFreeDoc(schema_doc);
    /* force the return value to be non-negative on success */
    return is_valid ? 1 : 0;
}

I guess the link is dead. Any chance that the tutorial is still live anywhere else? — miho, Dec 13 '14 at 13:07
Updated answer to have sample code. Anyone want to explain the downvotes or just due to deadlink? — JoeyJ, Dec 15 '14 at 22:50

score 0 · Answer 2 · edited May 23 '17 at 12:30

0

It appears that it is not exactly easy to do in Objective C, but there are several ideas listed at this S.O. question: Possible to validate xml against xsd using Objc/iPhone code at runtime

It seems CodeSynthesis supports this here : http://wiki.codesynthesis.com/Using_XSDE_in_iPhone_Applications

I am really just pulling links and ideas from the Stack Overflow question at this point, though.

edited May 23 '17 at 12:30

Community

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answered Jun 22 '12 at 20:38

kashev

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Yeah I did see the CodeSynthesis, though I wasn't crazy about it since its GPL and the setup for using in iOS seemed outdated and hard to follow =/ – JoeyJ Jun 22 '12 at 21:59

Teddy · Answer 3 · 2012-10-14T13:05:00.997

0

There is not a general schema validator. Try using XSDE as proposed above. It is very fast and very, very reliable.

Nice tutorial is here: http://amateuritsolutions.blogspot.hu/2012/10/validate-xsd-schema-in-your-ios.html

edited Oct 14 '12 at 13:05

answered Oct 14 '12 at 10:32

Teddy

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XSD Validation on iOS

3 Answers3