我刚开始接触XML解析。我完全不知道我们需要使用多少方法来进行XML解析，以及这些方法的作用是什么。我想要向Web服务发送输入，并通过使用XML解析将结果显示在我的文本字段中。
iPhone中的XML解析
3
- PradeepG
4
你可以很容易地找到如何开始的资源。我建议看一下NSXMLParser和它的代理方法。编码愉快。http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSXMLParser_Class/Reference/Reference.html - Jens Bergvall
这些方法都是委托，你不必处理它们所有。但是，您可能希望在范围内处理endelement和foundcharacters，以便您知道从xml中获取哪些项目。 - Praveen S
NSXMLParser是一个SAX解析器，相比许多DOM解析器，它更难使用。如果您只是从大型XML文档中提取少量数据，我建议使用TouchXML等解决方案而不是NSXMLParser。 - dtuckernet
这肯定会对你有所帮助 https://dev59.com/o0fRa4cB1Zd3GeqP70tX#12950155 请查看。 - Ravi_Parmar
7个回答
5
以下是有关如何为您的iOS应用程序选择XML解析器的资源：
我选择使用TouchXML进行我的项目。它是一个DOM解析器，支持XPath：
- dtuckernet
3
您应该使用以下方法：
在您的头文件中：
- (void)parseXMLFileAtURL:(NSString *)URL { //own method from me, URL could be local file or internet website
itemsOfFeed = [[NSMutableArray alloc] init];
NSURL *xmlURL = [NSURL URLWithString:URL];
feedParser = [[NSXMLParser alloc] initWithContentsOfURL:xmlURL];
[feedParser setDelegate:self];
[feedParser setShouldProcessNamespaces:NO];
[feedParser setShouldReportNamespacePrefixes:NO];
[feedParser setShouldResolveExternalEntities:NO];
[feedParser parse];
}
- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError {
//in case of an error
}
- (void)parserDidStartDocument:(NSXMLParser *)parser {
// start to parse xml
}
-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict {
feedElement = [elementName copy];
if([elementName isEqualToString:@"item"]) { //main xml tag
item = [[NSMutableDictionary alloc] init];
feedTitle = [[NSMutableString alloc] init];
feedDate = [[NSMutableString alloc] init];
feedText = [[NSMutableString alloc] init];
feedLink = [[NSMutableString alloc] init];
}
}
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {
if([feedElement isEqualToString:@"title"]) {
[feedTitle appendString:string];
} else if([feedElement isEqualToString:@"link"]) { // some examples of tags
[feedLink appendString:string];
} else if([feedElement isEqualToString:@"content:encoded"]) {
[feedText appendString:string];
} else if([feedElement isEqualToString:@"pubDate"]) {
[feedDate appendString:string];
}
}
- (void) parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName {
if([elementName isEqualToString:@"item"]) {
[item setObject:feedTitle forKey:@"title"];
[item setObject:feedDate forKey:@"date"];
[item setObject:feedText forKey:@"text"];
[item setObject:feedLink forKey:@"link"];
[itemsOfFeed addObject:item];
}
}
- (void)parserDidEndDocument:(NSXMLParser *)parser {
[self.myTableView reloadData]; // for example reload table view
[self writeArrayToFile]; //or write to a local property list
}
在您的头文件中：
NSMutableArray *itemsOfFeed;
NSXMLParser *feedParser;
NSMutableDictionary *item;
NSMutableString *feedElement;
NSMutableString *feedTitle, feedDate, feedText, feedLink; //strings of your tags
接下来你会看到：
- NSArray
- NSDictionary
- 对象a
- 对象b
- 对象c
- NSDictionary
只需访问 '对象a' 并将其放入您的文本字段中即可。
希望这个代码示例能够帮助您。
- tharkay
4
代码示例很棒！但是使用DOM解析器会更容易。如果用户只需要一个值，那么使用类似Touch XML的解决方案可以用4行代码替代所有这些代码。 - dtuckernet
当然，使用Touch XML可能更容易 :)
但是我在Touch XML不那么易于使用的时候创建了这段代码。 - tharkay
这个方法"[self.mWNetowrk makeRequsetWithURL:URL_SERVICES type:ReqLogin paramDictionary:paramDic delegate:self];"的意思是什么？它有什么用处？ - PradeepG
什么是ivar mWNetwork？我认为它将向“URL_SERVICES”服务器发送请求。其余部分应该是不言自明的：它需要登录，请求需要参数字典，委托是您的实现类。 - tharkay
2
这是非常有用的教程。
http://www.edumobile.org/iphone/iphone-programming-tutorials/parsing-an-xml-file/
（注：本文为中英文混合内容，无需翻译）
- Prerna
2
你好，我个人更喜欢使用NSXMLParser。
编写自己的代码，使用NSXMLParserDelegate方法实现。
但仍然有一些第三方库可用。这里有一个很好的示例，可以比较所有这些解析器之间的区别，并且还有很好的解释。代码也在那里提供。
希望这对你有所帮助。
-Mrunal
- Mrunal
0
试试这个：
XMLReader.h
//
// XMLReader.h
//
//
#import <Foundation/Foundation.h>
@interface XMLReader : NSObject <NSXMLParserDelegate>
{
NSMutableArray *dictionaryStack;
NSMutableString *textInProgress;
NSError *errorPointer;
}
+ (NSDictionary *)dictionaryForPath:(NSString *)path error:(NSError **)errorPointer;
+ (NSDictionary *)dictionaryForXMLData:(NSData *)data error:(NSError **)errorPointer;
+ (NSDictionary *)dictionaryForXMLString:(NSString *)string error:(NSError **)errorPointer;
@end
XMLReader.m
//
// XMLReader.m
//
#import "XMLReader.h"
//NSString *const kXMLReaderTextNodeKey = @"text";
@interface XMLReader (Internal)
- (id)initWithError:(NSError **)error;
- (NSDictionary *)objectWithData:(NSData *)data;
@end
@implementation XMLReader
#pragma mark -
#pragma mark Public methods
+ (NSDictionary *)dictionaryForPath:(NSString *)path error:(NSError **)errorPointer
{
NSString *fullpath = [[NSBundle bundleForClass:self] pathForResource:path ofType:@"xml"];
NSData *data = [[NSFileManager defaultManager] contentsAtPath:fullpath];
NSDictionary *rootDictionary = [XMLReader dictionaryForXMLData:data error:errorPointer];
return rootDictionary;
}
+ (NSDictionary *)dictionaryForXMLData:(NSData *)data error:(NSError **)error
{
XMLReader *reader = [[XMLReader alloc] initWithError:error];
NSDictionary *rootDictionary = [reader objectWithData:data];
[reader release];
return rootDictionary;
}
+ (NSDictionary *)dictionaryForXMLString:(NSString *)string error:(NSError **)error
{
NSArray* lines = [string componentsSeparatedByString:@"\n"];
NSMutableString* strData = [NSMutableString stringWithString:@""];
for (int i = 0; i < [lines count]; i++)
{
[strData appendString:[[lines objectAtIndex:i] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]];
}
NSData *data = [strData dataUsingEncoding:NSUTF8StringEncoding];
return [XMLReader dictionaryForXMLData:data error:error];
}
#pragma mark -
#pragma mark Parsing
- (id)initWithError:(NSError **)error
{
if ((self = [super init]))
{
errorPointer = *error;
}
return self;
}
- (void)dealloc
{
[dictionaryStack release];
[textInProgress release];
[super dealloc];
}
- (NSDictionary *)objectWithData:(NSData *)data
{
// Clear out any old data
[dictionaryStack release];
[textInProgress release];
dictionaryStack = [[NSMutableArray alloc] init];
textInProgress = [[NSMutableString alloc] init];
// Initialize the stack with a fresh dictionary
[dictionaryStack addObject:[NSMutableDictionary dictionary]];
// Parse the XML
NSXMLParser *parser = [[NSXMLParser alloc] initWithData:data];
parser.delegate = self;
BOOL success = [parser parse];
[parser release];
// Return the stack's root dictionary on success
if (success){
NSDictionary *resultDict = [dictionaryStack objectAtIndex:0];
return resultDict;
}
return nil;
}
# pragma mark
# pragma mark - NSXMLParserDelegate methods
- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
// Get the dictionary for the current level in the stack
NSMutableDictionary *parentDict = [dictionaryStack lastObject];
// Create the child dictionary for the new element
NSMutableDictionary *childDict = [NSMutableDictionary dictionary];
// Initialize child dictionary with the attributes, prefixed with '@'
for (NSString *key in attributeDict) {
[childDict setValue:[attributeDict objectForKey:key]
forKey:key];
}
// If there's already an item for this key, it means we need to create an array
id existingValue = [parentDict objectForKey:elementName];
if (existingValue){
NSMutableArray *array = nil;
if ([existingValue isKindOfClass:[NSMutableArray class]]){
// The array exists, so use it
array = (NSMutableArray *) existingValue;
}
else{
// Create an array if it doesn't exist
array = [NSMutableArray array];
[array addObject:existingValue];
// Replace the child dictionary with an array of children dictionaries
[parentDict setObject:array forKey:elementName];
}
// Add the new child dictionary to the array
[array addObject:childDict];
}
else{
// No existing value, so update the dictionary
[parentDict setObject:childDict forKey:elementName];
}
// Update the stack
[dictionaryStack addObject:childDict];
}
- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
{
// Update the parent dict with text info
NSMutableDictionary *dictInProgress = [dictionaryStack lastObject];
// Pop the current dict
[dictionaryStack removeLastObject];
// Set the text property
if ([textInProgress length] > 0){
if ([dictInProgress count] > 0){
[dictInProgress setObject:textInProgress forKey:kXMLReaderTextNodeKey];
}
else{
// Given that there will only ever be a single value in this dictionary, let's replace the dictionary with a simple string.
NSMutableDictionary *parentDict = [dictionaryStack lastObject];
id parentObject = [parentDict objectForKey:elementName];
// Parent is an Array
if ([parentObject isKindOfClass:[NSArray class]]){
[parentObject removeLastObject];
[parentObject addObject:textInProgress];
}
// Parent is a Dictionary
else{
[parentDict removeObjectForKey:elementName];
[parentDict setObject:textInProgress forKey:elementName];
}
}
// Reset the text
[textInProgress release];
textInProgress = [[NSMutableString alloc] init];
}
// If there was no value for the tag, and no attribute, then remove it from the dictionary.
else if ([dictInProgress count] == 0){
NSMutableDictionary *parentDict = [dictionaryStack lastObject];
[parentDict removeObjectForKey:elementName];
}
}
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
{
// Build the text value
[textInProgress appendString:[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]];
}
- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError
{
// Set the error pointer to the parser's error object
if (errorPointer)
errorPointer = parseError;
}
@end
使用方法：
NSMutableDictionary *yourDic= (NSMutableDictionary *)[XMLReader dictionaryForXMLData:yourData error:&error];
- NSPratik
0
以下是可用的第三方库，取决于开发者的选择，哪个最好呢？
- NSXMLParser
- libxml2
- TBXMLParser
- TouchXMLParser
- KissXMLParser
- TinyXMLParser
- GDataXMLParser
你还可以从这个很棒的教程链接中获取更多信息 http://www.raywenderlich.com/553/how-to-chose-the-best-xml-parser-for-your-iphone-project。
- SachinVsSachin
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