iOS XML转字典

#import <Foundation/Foundation.h>

enum {
XMLReaderOptionsProcessNamespaces           = 1 << 0, // Specifies whether the receiver reports the namespace and the qualified name of an element.
XMLReaderOptionsReportNamespacePrefixes     = 1 << 1, // Specifies whether the receiver reports the scope of namespace declarations.
XMLReaderOptionsResolveExternalEntities     = 1 << 2, // Specifies whether the receiver reports declarations of external entities.
};
typedef NSUInteger XMLReaderOptions;

@interface XMLReader : NSObject <NSXMLParserDelegate>

+ (NSDictionary *)dictionaryForXMLData:(NSData *)data error:(NSError **)errorPointer;
+ (NSDictionary *)dictionaryForXMLString:(NSString *)string error:(NSError **)errorPointer;
+ (NSDictionary *)dictionaryForXMLData:(NSData *)data options:(XMLReaderOptions)options error:(NSError **)errorPointer;
+ (NSDictionary *)dictionaryForXMLString:(NSString *)string options:(XMLReaderOptions)options error:(NSError **)errorPointer;

@end

#import "XMLReader.h"

#if !defined(__has_feature) || !__has_feature(objc_arc)
#error "XMLReader requires ARC support."
#endif

NSString *const kXMLReaderTextNodeKey		= @"text";
NSString *const kXMLReaderAttributePrefix	= @"@";

@interface XMLReader ()

@property (nonatomic, strong) NSMutableArray *dictionaryStack;
@property (nonatomic, strong) NSMutableString *textInProgress;
@property (nonatomic, strong) NSError *errorPointer;

@end

@implementation XMLReader

#pragma mark - Public methods

+ (NSDictionary *)dictionaryForXMLData:(NSData *)data error:(NSError **)error
{
XMLReader *reader = [[XMLReader alloc] initWithError:error];
NSDictionary *rootDictionary = [reader objectWithData:data options:0];
return rootDictionary;
}

+ (NSDictionary *)dictionaryForXMLString:(NSString *)string error:(NSError **)error
{
NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
return [XMLReader dictionaryForXMLData:data error:error];
}

+ (NSDictionary *)dictionaryForXMLData:(NSData *)data options:(XMLReaderOptions)options error:(NSError **)error
{
XMLReader *reader = [[XMLReader alloc] initWithError:error];
NSDictionary *rootDictionary = [reader objectWithData:data options:options];
return rootDictionary;
}

+ (NSDictionary *)dictionaryForXMLString:(NSString *)string options:(XMLReaderOptions)options error:(NSError **)error
{
NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
return [XMLReader dictionaryForXMLData:data options:options error:error];
}

#pragma mark - Parsing

- (id)initWithError:(NSError **)error
{
self = [super init];
if (self)
{
self.errorPointer = *error;
}
return self;
}

- (NSDictionary *)objectWithData:(NSData *)data options:(XMLReaderOptions)options
{
// Clear out any old data
self.dictionaryStack = [[NSMutableArray alloc] init];
self.textInProgress = [[NSMutableString alloc] init];

// Initialize the stack with a fresh dictionary
[self.dictionaryStack addObject:[NSMutableDictionary dictionary]];

// Parse the XML
NSXMLParser *parser = [[NSXMLParser alloc] initWithData:data];

[parser setShouldProcessNamespaces:(options & XMLReaderOptionsProcessNamespaces)];
[parser setShouldReportNamespacePrefixes:(options & XMLReaderOptionsReportNamespacePrefixes)];
[parser setShouldResolveExternalEntities:(options & XMLReaderOptionsResolveExternalEntities)];

parser.delegate = self;
BOOL success = [parser parse];

// Return the stack's root dictionary on success
if (success)
{
NSDictionary *resultDict = [self.dictionaryStack objectAtIndex:0];
return resultDict;
}

return nil;
}

#pragma mark -  NSXMLParserDelegate methods

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
// Get the dictionary for the current level in the stack
NSMutableDictionary *parentDict = [self.dictionaryStack lastObject];

// Create the child dictionary for the new element, and initilaize it with the attributes
NSMutableDictionary *childDict = [NSMutableDictionary dictionary];
[childDict addEntriesFromDictionary:attributeDict];

// If there's already an item for this key, it means we need to create an array
id existingValue = [parentDict objectForKey:elementName];
if (existingValue)
{
NSMutableArray *array = nil;
if ([existingValue isKindOfClass:[NSMutableArray class]])
{
// The array exists, so use it
array = (NSMutableArray *) existingValue;
}
else
{
// Create an array if it doesn't exist
array = [NSMutableArray array];
[array addObject:existingValue];

// Replace the child dictionary with an array of children dictionaries
[parentDict setObject:array forKey:elementName];
}

// Add the new child dictionary to the array
[array addObject:childDict];
}
else
{
// No existing value, so update the dictionary
[parentDict setObject:childDict forKey:elementName];
}

// Update the stack
[self.dictionaryStack addObject:childDict];
}

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
// Update the parent dict with text info
NSMutableDictionary *dictInProgress = [self.dictionaryStack lastObject];

// Set the text property
if ([self.textInProgress length] > 0)
{
// trim after concatenating
NSString *trimmedString = [self.textInProgress stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
[dictInProgress setObject:[trimmedString mutableCopy] forKey:kXMLReaderTextNodeKey];

// Reset the text
self.textInProgress = [[NSMutableString alloc] init];
}

// Pop the current dict
[self.dictionaryStack removeLastObject];
}

- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
// Build the text value
[self.textInProgress appendString:string];
}

- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError
{
// Set the error pointer to the parser's error object
self.errorPointer = parseError;
}

@end