GDataXMLNode应用

转自：http://blog.csdn.net/chowpan/article/details/8645224

1,安装：将GDataXMLNode文件加入至工程中->向Frameworks文件中添加libxml2.dylib库->在Croups & Files 侧边栏中双击工程图标，找到 build 修改两个属性：Search Paths中 找到Header Search Paths  将其对应的值修改为：/usr/include/libxml2，在Linking中找到 Other Linker Flags 对应的值改为：-lxml2。-------安装完成。

2,

//获取工程目录的xml文件

    NSString *filePath = [[NSBundlemainBundle] pathForResource:@"users"ofType:@"xml"];

    NSData *xmlData = [[NSDataalloc] initWithContentsOfFile:filePath];

    

    //使用NSData对象初始化

    NSError *error=nil;

    GDataXMLDocument *doc = [[GDataXMLDocumentalloc] initWithData:xmlData  options:0 error:&error];

    

    //获取根节点（Users）

    GDataXMLElement *rootElement = [doc rootElement];

    

    //获取根节点下的节点（User）

    NSArray *users = [rootElement elementsForName:@"User"];

    

    for (GDataXMLElement *userin users) {

        //User节点的id属性

        NSString *userId = [[user attributeForName:@"id"] stringValue];

        NSLog(@"User id is:%@",userId);

        

        //获取name节点的值

        GDataXMLElement *nameElement = [[userelementsForName:@"name"] objectAtIndex:0];

        NSString *name = [nameElement stringValue];

        NSLog(@"User name is:%@",name);

        

        //获取age节点的值

        GDataXMLElement *ageElement = [[userelementsForName:@"age"] objectAtIndex:0];

        NSString *age = [ageElement stringValue];

        NSLog(@"User age is:%@",age);

        NSLog(@"-------------------");

    }

    附：xml文件--

<?xml version="1.0" encoding="utf-8"?>

<Users>

    <User id="001">

        <name>Ryan</name>

        <age>24</age>

    </User>

    <User id="002">

        <name>Tang</name>

        <age>23</age>

    </User>

</Users>

----------------------------------------------------

GDataXml  相同标签的多个属性

GDataXml  相同标签的多个属性，好多文档都没有介绍获取属性的方法

GDataXMLDocument *doc=[[GDataXMLDocument alloc]initWithXMLString:resp*****eBody opti*****:2 error:nil];
    if (doc!=nil) {
GDataXMLElement *root=[doc rootElement ];
NSLog(@"--------root's children:--------\n%@", root);

//取出根节点的所有孩子节点
//取出某一个具体节点(body节点)

       [returnInfo setObject:[[[root elementsForName:@"db:uid"] objectAtIndex:0] stringValue] forKey:@"snsUserUid"];
      [returnInfo setObject:[[[root elementsForName:@"title"]objectAtIndex:0]stringValue] forKey:@"snsNickName"];  
        [returnInfo setObject:[[[root elementsForName:@"db:location"]objectAtIndex:0]stringValue] forKey:@"snsProvince"]; 
        [returnInfo setObject:[[[[root elementsForName:@"link"] objectAtIndex:2]attributeForName:@"href"] stringValue] forKey:@"snsProfileImageUrl"];
        [returnInfo setObject:@"4" forKey:@"snsLandEntrance"];
NSLog(@"%@",[[[root elementsForName:@"link"] objectAtIndex:2]attributes]);

NSLog(@"%@",[[[root elementsForName:@"db:location"]objectAtIndex:0]stringValue]);

    }


NSLog(@"returnInforeturnInforeturnInforeturnInforeturnInfo%@",returnInfo);




附上xml源文件：
<?xml version="1.0" encoding="UTF-8"?>
<entry xmlns="http://www.w3.org/2005/Atom" xmlns:db="http://www.douban.com/xmlns/" xmlns:gd="http://schemas.google.com/g/2005" xmlns:openSearch="http://a9.com/-/spec/opensearchrss/1.0/" xmlns:opensearch="http://a9.com/-/spec/opensearchrss/1.0/">
<id>http://api.douban.com/people/63522291</id>
<title>wangjianlewo</title>
<link href="http://api.douban.com/people/63522291" rel="self"/>
<link href="http://www.douban.com/people/63522291/" rel="alternate"/>
<link href="http://img3.douban.com/icon/user_normal.jpg" rel="icon"/>
<content></content>
<db:attribute name="n_mails">0</db:attribute>
<db:attribute name="n_notificati*****">0</db:attribute>
<db:location id="beijing">北京</db:location>
<db:signature></db:signature>
<db:uid>63522291</db:uid>
<uri>http://api.douban.com/people/63522291</uri>
</entry>

------------------------

下面是得到属性里的值。Google为我们做了很多的事情，不得不感慨GDataXMLNode给我们带来了如此多的便利
直接代码：


    NSArray *getItems = [document nodesForXPath:@"//item" error:&error];

这里给出了一个老外写的代码：
///////////////////////              截取属性应用举例                   
//NSInteger type=[[(GDataXMLNode *)[[urls objectAtIndex:i] attributeForName:@"type"] stringValue] intValue];
//NSInteger bit_stream=[[(GDataXMLNode *)[[urls objectAtIndex:i] attributeForName:@"bit_stream"] stringValue] intValue];


///////////////////////////////////////////
////       调试信息   看是否获取属性成功  //////
//////////////////////////////////////////
NSLog(@"%@",[(GDataXMLNode *)[[getItems objectAtIndex:0]attributeForName:@"name"]stringValue] );

//取出document对象     

      GDataXMLDocument* document = [[GDataXMLDocument alloc] initWithXMLString:myResponseStr options:2 error:nil];

      //取出xml的根节点

      GDataXMLElement* rootElement = [document rootElement];

      NSLog(@"--------root element:--------\n%@",rootElement);

      //取出根节点的所有孩子节点

      NSArray* children = [rootElement children];

      NSLog(@"--------root's children:--------\n%@", children);

      //取出某一个具体节点(body节点)

      GDataXMLElement* bodyElement = [[rootElement elementsForName:@"item"]objectAtIndex:1];

      NSLog(@"--------body:--------\n%@", bodyElement);

      //某个具体节点的文本内容

      NSString* content = [bodyElement stringValue];

      NSLog(@"--------body's content:--------\n%@", content);

//实例

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:   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).

2,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.
  <span style="color:#FF0000;">  //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</span>
  }

 - (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。