xml解析

结构化特征

DOM:Document Object Model 文档对象模型 有W3C 推荐

一次读取整个文档,整颗DOM树常驻内存,导致系统开销过大

SAX :Simple API for XML 并不是其推荐的标准 但是整个XML 行业的事实规范


xml解析_第1张图片

8.4.4 使用GDataXML解析XML文档

GDataXML 开源 对libxml2的包装  支持解析和修改 支持XPath

1.添加libxml2.dylib

2.添加/usr/include/libxml2    搜索路径

BuildSettings-Header Search Paths

PS:不支持ARC 需要手动关闭   -fno-objc-arc

下载GDataXML源代码

https://code.google.com/p/gdata-objectivec-client/source/browse/trunk/Source/XMLSupport/

http://down.51cto.com/data/619375

#import"GDataXMLNode.h"

#import"MyBook.h"

@interfaceViewController()

@property(weak,nonatomic)IBOutletUITextField*siteFild;

@end

@implementationViewController

//GDataXML解析

-(NSArray*)parseXML:(NSString*)xmlName

{

NSString* path=[[NSBundlemainBundle]pathForResource:xmlNameofType:@"xml"];

NSFileHandle* file=[NSFileHandlefileHandleForReadingAtPath:path];

NSData* data=[filereadDataToEndOfFile];

GDataXMLDocument* doc=[[GDataXMLDocumentalloc]initWithData:dataoptions:0error:nil];

//如果需要根据XML字符串来初始化GDataXMLDocument对象,则调用如下代码

//    GDataXMLDocument* doc=[[GDataXMLDocument alloc]initWithXMLString:NSXMLStr options:0 error:nil];

//获取根元素也就是获取元素

GDataXMLElement* rootELement=[docrootElement];

NSArray* bookElements=[rootELementelementsForName:@"book"];

//初始化一个可变数组,用于存储将要获取的所有元素组成的集合

NSMutableArray* books=[[NSMutableArrayalloc]init];

for(GDataXMLElement* bookElementinbookElements) {

NSIntegerbookID=[[[bookElementattributeForName:@"id"]stringValue]integerValue] ;

NSString* title=[[[bookElementelementsForName:@"title"]objectAtIndex:0]stringValue];

NSString* author=[[[bookElementelementsForName:@"author"]

objectAtIndex:0]stringValue];

NSString* remark=[[[bookElementelementsForName:@"remark"]objectAtIndex:0]stringValue];

MyBook* book=[[MyBookalloc]init];

book.bookID=bookID;

book.author=author;

book.title=title;

book.remark=remark;

[booksaddObject:book];

}

return[bookscopy];

}

8.4.5 使用GDataXML生成 修改XML文档

//

//  ViewController.m

//  5-8-1-XML

//

//  Created by童康on 16/5/8.

//  Copyright © 2016年童康. All rights reserved.

//

#import"ViewController.h"

#import"GDataXMLNode.h"

@interfaceViewController()

@property(weak,nonatomic)IBOutletUITextField*bookID;

@property(weak,nonatomic)IBOutletUITextField*bookName;

@property(weak,nonatomic)IBOutletUITextField*author;

@property(weak,nonatomic)IBOutletUITextField*remark;

@property(nonatomic,strong)NSString* xmlPath;

@end

@implementationViewController

- (void)viewDidLoad {

[superviewDidLoad];

[selfxmlPath];

// Do any additional setup after loading the view, typically from a nib.

}

- (IBAction)add:(id)sender {

NSString* bookID=self.bookID.text;

NSString* bookName=self.bookName.text;

NSString* author=self.author.text;

NSString* remark=self.remark.text;

if(bookID.length>0&& bookName.length>0&& author.length>0&&remark.length>0) {

//使用NSFileHandle对象根据文件路径获取到文件

NSFileHandle* file=[NSFileHandlefileHandleForReadingAtPath:self.xmlPath];

NSData* data=[filereadDataToEndOfFile];

GDataXMLDocument*doc;

//定义变量保存将要处理的XML文档对象

GDataXMLElement* rootEle;

if(data) {

//根据NSData对象初始化

doc=[[GDataXMLDocumentalloc]initWithData:dataoptions:0error:nil];

rootEle=doc.rootElement;

}

//如果XML文档还不存在,则需要新建文档

else

{

//创建元素

rootEle=[GDataXMLNodeelementWithName:@"books"];

GDataXMLElement* bookEle=[GDataXMLNodeelementWithName:@"id"stringValue:bookID];

//创建id属性,属性值为bookID

GDataXMLNode* attr=[GDataXMLNodeattributeWithName:@"id"stringValue:bookID];

[rootEleaddAttribute:attr];

//依次创建3个子元素

GDataXMLElement* titleEle=[GDataXMLNodeelementWithName:@"title"stringValue:bookName];

GDataXMLElement* authorEle=[GDataXMLNodeelementWithName:@"author"stringValue:author];

GDataXMLElement* remarkEle=[GDataXMLNodeelementWithName:@"remark"stringValue:remark];

//将3个子元素添加到bookEle元素中

[bookEleaddChild:titleEle];

[bookEleaddChild:authorEle];

[bookEleaddChild:remarkEle];

//将book元素添加入XML文档跟元素的子元素

[rootEleaddChild:bookEle];

//

if(!data) {

//以指定的根元素创建Document对象

doc=[[GDataXMLDocumentalloc]initWithRootElement:rootEle];

}

//将doc专为data

[doc.XMLDatawriteToFile:self.xmlPathatomically:YES];

self.bookID.text=nil;

self.bookName.text=nil;

self.author.text=nil;

self.remark.text=nil;

//创建并显示提示框

UIAlertView* alert=[[UIAlertViewalloc]initWithTitle:@"提示"message:@"添加成功!"delegate:selfcancelButtonTitle:@"确定"otherButtonTitles:nil];

[alertshow];

}

}else{

UIAlertView* alert=[[UIAlertViewalloc]initWithTitle:@"提示"message:@"您必须为所有信息都输入有效的值"delegate:selfcancelButtonTitle:@"确定"otherButtonTitles:nil];

[alertshow];

}

}

-(NSString*)xmlPath{

//获取应用程序沙盒的Documents路径

NSArray* paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);

NSString* documentsDirectory=[pathsobjectAtIndex:0];

NSLog(@"%@",documentsDirectory);

return[NSStringstringWithFormat:@"%@/books.xml",documentsDirectory];

}

- (void)didReceiveMemoryWarning {

[superdidReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end

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