iOS开发之html解析

使用XPath解析html

可以从此处https://github.com/topfunky/hpple下载工程，将TFHpple.h,TFHpple.m,TFHppleElement.h,TFHppleElement.m,XPathQuery.h,XPathQuery.m加到自己的项目中，在Frameworks中导入libxml2.x







在项目中找到Other Linker Flags，加入-libxml2





在项目中找到Header Search Paths，加入/usr/include/libxml2

代码如下：

NSString *urlString = nil;

urlString = @"http://www.xiyou.edu.cn/new/lm.jsp?urltype=tree.TreeTempUrl&wbtreeid=724";

NSData *htmlData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:urlString]];

NSData *toHtmlData = [self toUTF8:htmlData];

TFHpple *xpathParser = [[TFHpple alloc] initWithHTMLData:toHtmlData];

NSArray *aArray = [xpathParser searchWithXPathQuery:@"//a"];

if ([span count] > 0)
{

for (int i = 87;
i < 102; i++) {

//从<a>的第82个开始取值，共获取15个值

TFHppleElement *aElement = [aArray objectAtIndex:i];

NSArray *aArr = [aElement children];

TFHppleElement *aEle = [aArr objectAtIndex:0];

NSArray *aChild = [aEle children];

TFHppleElement *aChildEle = [aChild objectAtIndex:0];

NSArray *aChildren = [aChildEle children];

NSString *aStr = [[aChildren objectAtIndex:0] content];

NSLog(@"aStr:%@",aStr);

NSDictionary *aAttributeDict = [aElement attributes];

NSLog(@"aAttributeDict:%@",aAttributeDict);

//获取a中的属性值

NSString *hrefStr = [NSString stringWithFormat:@"http://www.xiyou.edu.cn%@",[aAttributeDict objectForKey:@"href"]];

NSLog(@"hrefStr:%@",hrefStr);

[currentNewsArr addObject:aStr];

[currentHrefArr addObject:hrefStr];

}

[htmlData release];

[xpathParser release];

}

//如果解析的网页不是utf8编码，如gbk编码，可以先将其转换为utf8编码再对其进行解析

-(NSData *) toUTF8:(NSData *)sourceData {

CFStringRef gbkStr
= CFStringCreateWithBytes(NULL,
[sourceData bytes], [sourceData length],kCFStringEncodingGB_18030_2000, false);

if (gbkStr == NULL)
{

return nil;

} else {

NSString *gbkString = (NSString *)gbkStr;

//根据网页源代码中编码方式进行修改，此处为从gbk转换为utf8

NSString *utf8_String
= [gbkString stringByReplacingOccurrencesOfString:@"META
http-equiv="Content-Type" content="text/html; charset=GBK""

withString:@"META
http-equiv="Content-Type" content="text/html; charset=UTF-8""];

return [utf8_String dataUsingEncoding:NSUTF8StringEncoding];

}

}

iphone:解析html的第三库hpple初试

用hpple较为便利的利用xpath解析html。
做法：http://lwxshow.com/ios-iphone-development-teaches-you-how-to-use-the-objective-c-parsing-html-lwxshow-com
（相关：
　　　　http://stackoverflow.com/questions/405749/parsing-html-on-the-iphone
http://stackoverflow.com/questions/9746745/xpath-attributes-selection
）
它里面说的挺详细的：就是引用 https://github.com/topfunky/hpple 上的hpple库，再结合libxml，就可以使用xpath搜索html了。
关于xpath的可以参考：w3school的教程 http://www.w3school.com.cn/xpath/index.asp
相关配置好了之后就可以直接使用：

- (void)viewDidLoad
{
[super viewDidLoad];
NSError *error;

NSData *htmlData = [[NSString stringWithContentsOfURL:[NSURL
URLWithString: @"http://dict.youdao.com/m/search?keyfrom=dict.mindex&vendor=&q=apple"]
encoding:NSASCIIStringEncoding error:&error]
dataUsingEncoding:NSUTF8StringEncoding];
TFHpple *xpathParser = [[TFHpple alloc] initWithHTMLData:htmlData];
NSArray *elements  = [xpathParser searchWithXPathQuery:@"//title"]; // get the title
NSLog(@"%d",[elements count]);
TFHppleElement *element = [elements objectAtIndex:0];

NSString *content = [element content];
NSString *tagname = [element tagName];
NSString *attr = [element objectForKey:@"href"];
NSLog(@"content = %@",content);
NSLog(@"tagname = %@",tagname);
NSLog(@"attr is = %@",attr);
}

//

// TFHppleElement.m

// Hpple

//

// Created by Geoffrey Grosenbach on 1/31/09.

//

// Copyright (c) 2009 Topfunky Corporation,
http://topfunky.com
//

// MIT LICENSE

//

// Permission is hereby granted, free of charge, to any person obtaining

// a copy of this software and associated documentation files (the

// "Software"), to deal in the Software without restriction, including

// without limitation the rights to use, copy, modify, merge, publish,

// distribute, sublicense, and/or sell copies of the Software, and to

// permit persons to whom the Software is furnished to do so, subject to

// the following conditions:

//

// The above copyright notice and this permission notice shall be

// included in all copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE

// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION

// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION

// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

#import
"TFHppleElement.h"

static
NSString
*
const
TFHppleNodeContentKey
= @"nodeContent";

static
NSString
*
const
TFHppleNodeNameKey
= @"nodeName";

static
NSString
*
const
TFHppleNodeChildrenKey
= @"nodeChildArray";

static
NSString
*
const
TFHppleNodeAttributeArrayKey
= @"nodeAttributeArray";

static
NSString
*
const
TFHppleNodeAttributeNameKey
= @"attributeName";

@interface
TFHppleElement ()

@property (nonatomic, retain, readwrite)
TFHppleElement
*parent;

@end

@implementation
TFHppleElement

@synthesize parent;

- (void) dealloc

{

[node release];

[parent release];

[super dealloc];

}

- (id) initWithNode:(NSDictionary
*) theNode

{

if (!(self
= [super init]))

return nil;

[theNode retain];

node
= theNode;

return self;

}

+ (TFHppleElement
*) hppleElementWithNode:(NSDictionary
*) theNode {

return [[[[self
class] alloc] initWithNode:theNode] autorelease];

}

#pragma mark
-

- (NSString
*) content

{

return [node objectForKey:TFHppleNodeContentKey];

}

- (NSString
*) tagName

{

return [node objectForKey:TFHppleNodeNameKey];

}

- (NSArray
*) children

{

NSMutableArray
*children
= [NSMutableArray array];

for (NSDictionary
*child
in [node objectForKey:TFHppleNodeChildrenKey]) {

TFHppleElement
*element
= [TFHppleElement hppleElementWithNode:child];

element.parent
= self;

[children addObject:element];

}

return children;

}

- (TFHppleElement
*) firstChild

{

NSArray
* children
= self.children;

if (children.count)

return [children objectAtIndex:0];

return nil;

}

- (NSDictionary
*) attributes

{

NSMutableDictionary
* translatedAttributes
= [NSMutableDictionary dictionary];

for (NSDictionary
* attributeDict
in [node objectForKey:TFHppleNodeAttributeArrayKey]) {

[translatedAttributes setObject:[attributeDict objectForKey:TFHppleNodeContentKey]

forKey:[attributeDict objectForKey:TFHppleNodeAttributeNameKey]];

}

return translatedAttributes;

}

- (NSString
*) objectForKey:(NSString
*) theKey

{

return [[self attributes] objectForKey:theKey];

}

- (id) description

{

return [node description];

}

@end