iOS 解析 HTML

xml,json都有大量的库来解析，我们如何解析html呢？

TFHpple是一个小型的封装，可以用来解析html，它是对libxml的封装，语法是xpath。

今天我看到一个直接用libxml来解析html，参看：http://www.cocoanetics.com/2011/09/taming-html-parsing-with-libxml-1/#comment-3090 那张图画得一目了然，很值得收藏。这个文章中的源码不能遍历所有的html，我做了一点修改可以将html遍历打印出来

001	// NSData data contains the document data

002	// encoding is the NSStringEncoding of the data

003	// baseURL the documents base URL, i.e. location

004

005	CFStringEncoding cfenc = CFStringConvertNSStringEncodingToEncoding(encoding);

006	CFStringRef cfencstr = CFStringConvertEncodingToIANACharSetName(cfenc);

007	const char*enc = CFStringGetCStringPtr(cfencstr, 0);

008

009	htmlDocPtr _htmlDocument = htmlReadDoc([data bytes],

010	[[baseURL absoluteString] UTF8String],

011

enc,

012	XML_PARSE_NOERROR | XML_PARSE_NOWARNING);

013	if(_htmlDocument)

014

{

015	xmlFreeDoc(_htmlDocument);

016

}

017

018	xmlNodePtr currentNode = (xmlNodePtr)_htmlDocument;

019

020	while(currentNode)

021

{

022	// output node if it is an element

023

024	if(currentNode->type == XML_ELEMENT_NODE)

025

{

026	NSMutableArray *attrArray = [NSMutableArray array];

027

028	for(xmlAttrPtr attrNode = currentNode->properties; attrNode; attrNode = attrNode->next)

029

{

030	xmlNodePtr contents = attrNode->children;

031

032	[attrArray addObject:[NSString stringWithFormat:@"%s='%s'", attrNode->name, contents->content]];

033

}

034

035	NSString *attrString = [attrArray componentsJoinedByString:@" "];

036

037	if([attrString length])

038

{

039	attrString = [@" "stringByAppendingString:attrString];

040

}

041

042	NSLog(@"<%s%@>", currentNode->name, attrString);

043

}

044	else if(currentNode->type == XML_TEXT_NODE)

045

{

046	//NSLog(@"%s", currentNode->content);

047	NSLog(@"%@", [NSString stringWithCString:(const char*)currentNode->content encoding:NSUTF8StringEncoding]);

048

}

049	else if(currentNode->type == XML_COMMENT_NODE)

050

{

051	NSLog(@"/* %s */", currentNode->name);

052

}

053

054

055	if(currentNode && currentNode->children)

056

{

057	currentNode = currentNode->children;

058

}

059	else if(currentNode && currentNode->next)

060

{

061	currentNode = currentNode->next;

062

}

063

else

064

{

065	currentNode = currentNode->parent;

066

067	// close node

068	if(currentNode && currentNode->type == XML_ELEMENT_NODE)

069

{

070	NSLog(@"</%s>", currentNode->name);

071

}

072

073	if(currentNode->next)

074

{

075	currentNode = currentNode->next;

076

}

077

else

078

{

079	while(currentNode)

080

{

081	currentNode = currentNode->parent;

082	if(currentNode && currentNode->type == XML_ELEMENT_NODE)

083

{

084	NSLog(@"</%s>", currentNode->name);

085	if (strcmp((const char*)currentNode->name, "table") == 0)

086

{

087	NSLog(@"over");

088

}

089

}

090

091	if(currentNode == nodes->nodeTab[0])

092

{

093

break;

094

}

095

096	if(currentNode && currentNode->next)

097

{

098	currentNode = currentNode->next;

099

break;

100

}

101

}

102

}

103

}

104

105	if(currentNode == nodes->nodeTab[0])

106

{

107

break;

108

}

109

}

 

不过我还是喜欢用TFHpple，因为它很简单，也好用，但是它的功能不是很完完善。比如，不能获取children node,我就写了两个方法，一个是获取children node,一个是获取所有的contents.  还有node的属性content的key与node's content的key一样，都是@"nodeContent", 正确情况下属性的应是@"attributeContent"，

所以我写了这个方法，同时修改node属性的content key.

01	NSDictionary *DictionaryForNode2(xmlNodePtr currentNode, NSMutableDictionary *parentResult)

02

{

03	NSMutableDictionary *resultForNode = [NSMutableDictionary dictionary];

04

05	if(currentNode->name)

06

{

07	NSString *currentNodeContent =

08	[NSString stringWithCString:(const char*)currentNode->name encoding:NSUTF8StringEncoding];

09	[resultForNode setObject:currentNodeContent forKey:@"nodeName"];

10

}

11

12	if(currentNode->content)

13

{

14	NSString *currentNodeContent = [NSString stringWithCString:(const char*)currentNode->content encoding:NSUTF8StringEncoding];

15

16	if(currentNode->type == XML_TEXT_NODE)

17

{

18	if(currentNode->parent->type == XML_ELEMENT_NODE)

19

{

20	[parentResult setObject:currentNodeContent forKey:@"nodeContent"];

21	returnnil;

22

}

23

24	if(currentNode->parent->type == XML_ATTRIBUTE_NODE)

25

{

26	[parentResult

27	setObject:

28	[currentNodeContent

29	stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]

30	forKey:@"attributeContent"];

31	returnnil;

32

33

}

34

}

35

}

36

37

38

39	xmlAttr *attribute = currentNode->properties;

40	if(attribute)

41

{

42	NSMutableArray *attributeArray = [NSMutableArray array];

43	while(attribute)

44

{

45	NSMutableDictionary *attributeDictionary = [NSMutableDictionary dictionary];

46	NSString *attributeName =

47	[NSString stringWithCString:(const char*)attribute->name encoding:NSUTF8StringEncoding];

48	if(attributeName)

49

{

50	[attributeDictionary setObject:attributeName forKey:@"attributeName"];

51

}

52

53	if(attribute->children)

54

{

55	NSDictionary *childDictionary = DictionaryForNode2(attribute->children, attributeDictionary);

56	if(childDictionary)

57

{

58	[attributeDictionary setObject:childDictionary forKey:@"attributeContent"];

59

}

60

}

61

62	if([attributeDictionary count] > 0)

63

{

64	[attributeArray addObject:attributeDictionary];

65

}

66	attribute = attribute->next;

67

}

68

69	if([attributeArray count] > 0)

70

{

71	[resultForNode setObject:attributeArray forKey:@"nodeAttributeArray"];

72

}

73

}

74

75	xmlNodePtr childNode = currentNode->children;

76	if(childNode)

77

{

78	NSMutableArray *childContentArray = [NSMutableArray array];

79	while(childNode)

80

{

81	NSDictionary *childDictionary = DictionaryForNode2(childNode, resultForNode);

82	if(childDictionary)

83

{

84	[childContentArray addObject:childDictionary];

85

}

86	childNode = childNode->next;

87

}

88	if([childContentArray count] > 0)

89

{

90	[resultForNode setObject:childContentArray forKey:@"nodeChildArray"];

91

}

92

}

93

94	returnresultForNode;

95

}

 

TFHppleElement.m里加了两个key 常量

1	NSString * constTFHppleNodeAttributeContentKey  = @"attributeContent";

2	NSString * const TFHppleNodeChildArrayKey        = @"nodeChildArray";

 

并修改获取属性方法为：

1	- (NSDictionary *) attributes

2

{

3	NSMutableDictionary * translatedAttributes = [NSMutableDictionary dictionary];

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

5	[translatedAttributes setObject:[attributeDict objectForKey:TFHppleNodeAttributeContentKey]

6	forKey:[attributeDict objectForKey:TFHppleNodeAttributeNameKey]];

7

}

8	returntranslatedAttributes;

9

}

 

并添加获取children node 方法：

01	- (BOOL) hasChildren

02

{

03	NSArray *childs = [node objectForKey: TFHppleNodeChildArrayKey];

04

05	if(childs)

06

{

07	return YES;

08

}

09

10	return NO;

11

}

12

13	- (NSArray *) children

14

{

15	if([self hasChildren])

16	return[node objectForKey: TFHppleNodeChildArrayKey];

17	returnnil;

18

}

 

最后我还加了一个获取所有content的主法：

1	- (NSString *)contentsAt:(NSString *)xPathOrCss;

 

请看 源码。