IOS开发中使用GDataXmlNode解析xml

       xml的解析在ios网络开发的时候非常常见，不同的xml的树形的结构各不相同，这篇文中介绍根据不同的xml的结构解析出xml，保存到字典中，如果解析的数据将会多次用到，建议建立数据实体，不然在多个场景中都必须知道字典中的键值，用起来非常不方便。

      我最近开发的项目中用到xml解析，我用到一个工厂模式来建立一个解析的方式。

1：下载GDataXmlNode.h 和GDataXmlNode.m，并添加到项目中，具体的使用和和配置方法在GDataXmlNode.h 的注释中有，这步就不分解了，在不行就google下

2:   我在这个过程中用到6个文件，BaseParser.h,BaseParser.m,DataParser.h和DataParser.m ,LoginParser.h,LoginParser.m,其中BaseParser用于定义和实现基类的方法，LoginParser继承于BaserParser,实现了父类中申明的解析xml文件和组装xml文件的方法。DataParser中根据不同的xml类型来实例化解析类，这里就是LoginParser(也就是说，还可以实例化任意多个BaseParser的子类).

3,GDataxmlNode 的使用在LoginParser中很能得以体现总的思路就是  字典，字符串，GDataxmlDocumet 这个类型的实例之间相互转化，以完成xml的组装和解析。

BaseParser.h

#import <Foundation/Foundation.h>#import "GDataXMLNode.h"@interface BaseParser : NSObject{    NSString                                      *xmlContent;        //字符串形式的xml内容    NSMutableDictionary            *parsedContent; //对应的字典}@property(nonatomic,retain)NSString *xmlContent;- (id)initWithXmlString:(NSString *)xmlString;- (NSDictionary *)getCurrentList;- (id)initWithUserDicionary:(NSDictionary*)dicionary;- (id)getCurrentData;@end

BaseParser.m

#import "BaseParser.h"@implementation Baseparser@synthesize xmlContent;-(id)init{    self = [super init];    if (self) {        parsedContent = [[NSMutableDictionary alloc]init];        xmlContent    = [[NSString alloc]init];    }    return self;}-(void)dealloc{    [parsedContent release];    [xmlContent release];    [super dealloc];    }- (id)initWithXmlString:(NSString *)xmlString{    return nil;}- (id)initWithUserDicionary:(NSDictionary *)dicionary{    return nil;}- (NSDictionary *)getCurrentList{return [NSDictionary dictionaryWithDictionary:parsedContent]; }- (id)getCurrentData{    return [NSString stringWithString:xmlContent];}

LoginParser.h

#import <Foundation/Foundation.h>#import "BaseParser.h"@interface LoginParser : BaseParser@end

LoginParser.m

#import "LoginParser.h"@implementation LoginParser- (void)dealloc{    [super dealloc];}- (id)initWithXmlString:(NSString *)xmlString{    self = [super init];    if (self) {        NSError *error;        GDataXMLDocument *dataDocument = [[GDataXMLDocument alloc]initWithXMLString:xmlString options:0 error:&error ];        GDataXMLElement *root = [dataDocument rootElement];        NSArray *array = [NSArray arrayWithObjects:@"code",@"desc",@"sessionId",@"user_id",@"name", nil];        for (int index = 0; index<[array count]; index++) {            GDataXMLElement *element = [[root elementsForName:[array objectAtIndex:index]]lastObject];            NSString *aValue = (NSString*)[element stringValue];            if (aValue) {                [parsedContent  setObject:aValue forKey:[array objectAtIndex:index]];            }        }        [dataDocument release];            }return self;}- (id)initWithUserDicionary:(NSDictionary *)dicionary{    self = [self init];    if (self) {        [dicionary retain];        GDataXMLElement *rootElement = [GDataXMLElement elementWithName:@"root"];        NSArray *elementArray = [NSArray arrayWithObjects:@"name",@"type",@"password", nil];        for (int index = 0; index<[elementArray count]; index++) {            GDataXMLElement *element = [GDataXMLElement elementWithName:[elementArray objectAtIndex:index] stringValue:[dicionary objectForKey:[elementArray objectAtIndex:index]]];            [rootElement addChild:element];        }        [dicionary release];        GDataXMLDocument *xmlDocument = [[GDataXMLDocument alloc]initWithRootElement:rootElement];        NSString *xmlString = [[NSString alloc]initWithData:xmlDocument.XMLData encoding:NSUTF8StringEncoding];        xmlContent = @"";        xmlContent = [xmlContent stringByAppendingString:xmlString];        [xmlString release];        [xmlDocument release];            }        return self;}

DataParser.h

#import <Foundation/Foundation.h>@interface DataParser : NSObject+ (id)CreateParserObjectWithData:(id)xmlString andTypeIs:(NSInteger)aType;     // 根据不同的类型用字典组装成xml+ (id)CreateDeparserObjectWithData:(id)xmlString andTypeIs:(NSInteger)aType;//将xml解析成字典@end

DataParser.m

#import "LoginParser.h"@implementation DataParser//这俩个简单的工厂来组装和解析xml + (id)CreateParserObjectWithData:(id)xmlString andTypeIs:(NSInteger)aType{    switch (aType) {        case LOGINSERVICETYPE :        {            LoginParser *parser  = [[BCLogin alloc]initWithXmlString:xmlString];            NSDictionary *dictionary = [urlList getCurrentList];            [ parser release];            return dictionary ;        }            break;}

+ (id)CreateDeparserObjectWithData:(id)xmlString andTypeIs:(NSInteger)aType{        switch (aType) {        case LOGINSERVICETYPE :        {            LoginParser *parser = [[BCLogin alloc]initWithUserDicionary:xmlString];            NSData  *data    = [urlList getCurrentData];            [parser release];            return data ;        }            break;}

4:使用

新建一个文件LoginViewController,在程序束中加入 LoginReturn.xml,

LoginViewController.m

#define    LOGINSERVICETYPE  100#import "LoginViewController.h"@implementation LoginViewController- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];    if (self) {        // Custom initialization    }    return self;}- (void)didReceiveMemoryWarning{    // Releases the view if it doesn't have a superview.    [super didReceiveMemoryWarning];        // Release any cached data, images, etc that aren't in use.}#pragma mark - View lifecycle- (void)viewDidLoad{    [super viewDidLoad];    // Do any additional setup after loading the view from its nib.   //使用解析的工厂，组装xml就不写了    NSString *string =  NSError *error;    NSString *xmlString = [NSString stringWithContentsOfFile:[[[NSBundle mainBundle]bundlePath]stringByAppendingPathComponent:@"LoginReturn.xml"]      encoding:NSUTF8StringEncoding error:&error];     NSMutableDictionary *dic =    [NSMutableDictionary dictionaryWithDictionary:                                                                   [BCBaseParser CreateParserObjectWithData:xmlString andTypeIs:self.parserType]]   //这里获得的dic就是包含了sessionId,userId,等键的字典 }- (void)viewDidUnload{    [super viewDidUnload];    // Release any retained subviews of the main view.    // e.g. self.myOutlet = nil;}- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{    // Return YES for supported orientations    return (interfaceOrientation == UIInterfaceOrientationPortrait);}@end

 不好把我在项目中的代码貼出来，我是在post不同的xml中用到这个方式

转载请注明出处

总结：

        代码的重用非常重要，在开发过程中尽量遵守一般的开发原则，比如OCP，这篇文中较好的体现了这一原则，同时GDataXmlNode避免了官方的类回调的使用，十分方便，推荐使用。