XMLStreamReader for Objective C iPhone?

I am using XMLWriter for generating the xml. Now I want to read this xml with some Reader library/framework. Is there any complement开发者_运维知识库ary framework/library available for this.

I am currently looking to use TouchXML library to read this, but its not working in the expected way as it does not support stream reading.

I want do something like:

XmlReader pReader = XmlTextReader.Create(pPath);

    while (pReader.Read()){

        switch (pReader.LocalName){
            case EXPEL_DEVICES:
            {
                //if ((pImportFlags & (int)ExportClass.Devices) != 0)
                //{
                for (pReader.ReadToFollowing(LOCAL_NAME, NAMESPACE_EXPORT);
                     !pReader.EOF && pReader.LocalName == @"NAME"; )
                {
                    if (!pReader.ReadToFollowing(DEVICE_ID, NAMESPACE_EXPORT))
                        throw new AException(DEVICE_ID);
                    NSString *value = pReader.ReadElementContentAsString();
                }
            }
                break;
        }
    }

After loosing my own reputation worth 50, I finally used libxml2 and made my XMLStreamReader class as following, I wish I could have found this earlier :P. Please note that for using this we need include libxml2.dylib inot our frameworks and in the build settings do add -lxml2 into other linker flags and in header search paths add /usr/include/libxml2

The header file:

#import <Foundation/Foundation.h>
#import <libxml/xmlreader.h>

@interface XMLStreamReader : NSObject {
    xmlTextReaderPtr xmlReader;
}

@property (nonatomic, readonly, assign) BOOL eof;
@property (nonatomic, readonly, retain) NSString *localName;
@property (nonatomic, readonly, assign) xmlElementType nodeType;
@property (nonatomic, readonly, assign) BOOL read;
@property (nonatomic, readonly, assign) BOOL readElementContentAsBoolean;
@property (nonatomic, readonly, retain) NSString *readElementContentAsString;

- (void) close;
- (id) getAttribute:(NSString *) paramName;
- (id) initWithPath:(NSString *) path;
@end

The implementation file:

#import "XMLStreamReader.h"

@implementation XMLStreamReader

@dynamic eof;
@dynamic localName;
@dynamic nodeType;
@dynamic read;
@dynamic readElementContentAsBoolean;
@dynamic readElementContentAsString;

- (void) dealloc{
    xmlFreeTextReader(xmlReader);
    [super dealloc];
}

/**
 * xmlTextReaderClose:
 * @reader:  the xmlTextReaderPtr used
 *
 * This method releases any resources allocated by the current instance
 * changes the state to Closed and close any underlying input.
 *
 * Returns 0 or -1 in case of error
 */
- (void) close{
    xmlTextReaderClose(xmlReader);
}

/**
 * @reader:  the xmlTextReaderPtr used
 * @name: the qualified name of the attribute.
 *
 * Provides the value of the attribute with the specified qualified name.
 *
 * Returns a string containing the value of the specified attribute, or NULL
 *    in case of error. The string must be deallocated by the caller.
 */
- (id) getAttribute:(NSString *) paramName{
    xmlChar *attribute = xmlTextReaderGetAttribute(xmlReader, (xmlChar *)[paramName UTF8String]);

    if(attribute != NULL){
        NSString *rtString = [NSString stringWithUTF8String:(const char *)attribute];
        free(attribute);
        return rtString;
    }
    return NULL;
}

/**
 * Checks if, the reader has reached to the end of file
 * 'EOF' is not used as it is already defined in stdio.h
 * as '#define  EOF (-1)'
 */
- (BOOL) eof{
    return xmlTextReaderReadState(xmlReader) == XML_TEXTREADER_MODE_EOF;
}

/**
 * Initializing the xml stream reader with some uri
 * or local path.
 */
- (id) initWithPath:(NSString *) path{
    if(self = [super init]){
        xmlReader = xmlNewTextReaderFilename([path UTF8String]);
        if(xmlReader == NULL)
            return nil;
    }
    return self;
}

/**
 * @reader:  the xmlTextReaderPtr used
 *
 * The local name of the node.
 *
 * Returns the local name or NULL if not available,
 *   if non NULL it need to be freed by the caller.
 */
- (NSString *) localName{
    xmlChar *lclName = xmlTextReaderLocalName(xmlReader);

    if(lclName != NULL){
        NSString *rtString = [NSString stringWithUTF8String:(const char *)lclName];
        free(lclName);
        return rtString;
    }
    return NULL;
}

- (xmlElementType) nodeType{
    return xmlTextReaderNodeType(xmlReader);
}

/**
 * @reader:  the xmlTextReaderPtr used
 *
 *  Moves the position of the current instance to the next node in
 *  the stream, exposing its properties.
 *
 *  Returns 1 if the node was read successfully, 0 if there is no more
 *          nodes to read, or -1 in case of error
 */
- (BOOL) read{
    return xmlTextReaderRead(xmlReader);
}

/**
 * @reader:  the xmlTextReaderPtr used
 *
 * Reads the contents of an element or a text node as a Boolean.
 *
 * Returns a string containing the contents of the Element or Text node,
 *         or NULL if the reader is positioned on any other type of node.
 *         The string must be deallocated by the caller.
 */
- (void) readElementContentAsBoolean{
    return [[self readElementContentAsString] boolValue];
}

/**
 * @reader:  the xmlTextReaderPtr used
 *
 * Reads the contents of an element or a text node as a string.
 *
 * Returns a string containing the contents of the Element or Text node,
 *         or NULL if the reader is positioned on any other type of node.
 *         The string must be deallocated by the caller.
 */
- (NSString *) readElementContentAsString{
    xmlChar *content = xmlTextReaderReadString(xmlReader);

    if(content != NULL){
        NSString *rtString = [NSString stringWithUTF8String:(const char *)content];
        free(content);
        return rtString;
    }
    return NULL;
}

/**
 * @reader:  the xmlTextReaderPtr used
 * @localName:  the local name of the attribute.
 * @namespaceURI:  the namespace URI of the attribute.
 *
 * Moves the position of the current instance to the attribute with the
 * specified local name and namespace URI.
 *
 * Returns 1 in case of success, -1 in case of error, 0 if not found
 */
- (int) readToFollowing:(NSString *) localname namespace:(NSString *) namespaceURI{
    return xmlTextReaderMoveToAttributeNs(xmlReader, (xmlChar *)[localname UTF8String], (xmlChar *)[namespaceURI UTF8String]);
}

@end

NSXMLParser is included in Foundation, that may meet your needs.

You could go straight to the source using libxml2, and their XmlReader API. It's based off the XmlReader API in C# that you appear to have referenced above, but in C.

I realize it's not objective-c, but you could easily wrap the functionality in a class that's accessed by the rest of your project.