objective-c 中队libxml2 小封装了下。

最新推荐文章于 2023-03-03 10:14:58 发布

原创最新推荐文章于 2023-03-03 10:14:58 发布 · 1.3k 阅读

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文章标签：

#null #string #interface #xml

本文介绍了如何在Objective-C中对libxml2库进行小规模的封装，以方便在XML处理中使用。通过创建接口和实现基本的XML解析功能，简化了XML文档的读取和操作过程。

//
//  LibXmlEx.h
//  libXml2Conv
//
//  Created by xxxx on 11-11-8.
//  Copyright 2011 __MyCompanyName__. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "iconv.h"
#import <libxml/parser.h>
#import <libxml/xpath.h>


@interface LibXmlEx : NSObject {
    
    NSString    *m_strFilePath;
    xmlDocPtr   m_pDoc;

}

//init
- (id) initXmlWithPath:(NSString*)strFilePath;

- (id) initXmlWithString:(NSString*)strData;

//finder
- (NSString*) getXmlString:(NSString*)strXpath;

//writer
- (BOOL) writeXmlString:(NSString*)strValue withXpath:(NSString*)strXpath;

//save
- (BOOL) saveXmlFile;


//tools
+ (NSString*) DocumentFilePath:(NSString*)strFileName;

@end

//
//  LibXmlEx.m
//  libXml2Conv
//
//  Created by xxxx on 11-11-8.
//  Copyright 2011 __MyCompanyName__. All rights reserved.
//
/*
 Sample:
 LibXmlEx* par = [[LibXmlEx alloc]initXmlWithString:xml];
 NSString* strupg = [par getXmlString:@"/AuthenticateResp/upgradedomain"];
 NSLog(@"======%@=======",strupg);
 [par release];
*/

#import "LibXmlEx.h"

#pragma mark -
@interface LibXmlEx (private)

- (int) code_convert:(char*)from_charset to:(char*)to_charset inBuffer:(char*)inbuf
            inLength:(int)inlen outBuffer:(char*)outbuf outLength:(int)outlen;

- (char*) u2g:(char*)inbuf;
- (char*) g2u:(char*)inbuf;

- (xmlXPathObjectPtr) get_nodeset:(xmlChar*)xpath;

@end


#pragma mark -
@implementation LibXmlEx


- (void) dealloc
{
	if (NULL != m_pDoc) {
		xmlFreeDoc(m_pDoc);
		m_pDoc = NULL;
	}
    [super dealloc];
}


- (id) init
{
    if (self = [super init]) {
        
    }
    return self;
}

- (id) initXmlWithPath:(NSString*)strFilePath
{
    if (self = [super init]) {
        
		if (NULL != strFilePath) {
			m_strFilePath = [NSString stringWithFormat:@"%@",strFilePath];
			xmlNodePtr curNodePtr;
			
			m_pDoc = xmlReadFile([strFilePath UTF8String], "GB2312", XML_PARSE_RECOVER);
			if (NULL == m_pDoc) {
				NSLog(@"%@",@"Document not paresed sucessfully.");
				xmlFreeDoc(m_pDoc);
				return self;
			}
			curNodePtr = xmlDocGetRootElement(m_pDoc);
			
			if (NULL == curNodePtr) {
				NSLog(@"%@",@"empty document");
				xmlFreeDoc(m_pDoc);
				return self;
			}			
		}
        
    }
    return self;
}

- (id) initXmlWithString:(NSString*)strData
{
    if (self = [super init]) {
        if (NULL != strData) {
			xmlNodePtr curNodePtr;
			
			m_pDoc = xmlReadMemory([strData UTF8String], [strData length], NULL, "GB2312", XML_PARSE_RECOVER);
			if (NULL == m_pDoc) {
				NSLog(@"%@",@"Document not paresed sucessfully.");
				xmlFreeDoc(m_pDoc);
				return self;
			}
			curNodePtr = xmlDocGetRootElement(m_pDoc);
			
			if (NULL == curNodePtr) {
				NSLog(@"%@",@"empty document");
				xmlFreeDoc(m_pDoc);
				return self;
			}			
		}
    }
    return self;
}

- (NSString*) getXmlString:(NSString*)strXpath
{
    xmlXPathObjectPtr result;
    const char* strRel;
    
    result = [self get_nodeset:BAD_CAST [strXpath UTF8String]];
    
    if (NULL == result) {
        NSLog(@"%@",@"get_nodeset return NULL");
        return NULL;
    }
    
    xmlNodeSetPtr nodeSetPtr = result->nodesetval;
    
    if (xmlXPathNodeSetIsEmpty(nodeSetPtr)) {
        xmlXPathFreeObject(result);
        NSLog(@"%@",@"xmlXPathNodeSetIsEmpty");
        return NULL;
    }
    
    xmlNodePtr nodePtr = nodeSetPtr->nodeTab[0];
    
    strRel = (const char*)xmlNodeGetContent(nodePtr);
    
    if (NULL == strRel) {
        return NULL;
    }
    
    return [NSString stringWithUTF8String:strRel];
}

- (BOOL) writeXmlString:(NSString*)strValue withXpath:(NSString*)strXpath
{
	xmlXPathObjectPtr result;
	
	result = [self get_nodeset:BAD_CAST [strXpath UTF8String]];
	if (result == NULL) 
	{
		NSLog(@"%@",@"xmlXPathEvalExpression return NULL"); 
		return NO;  
	}
	
	xmlNodeSetPtr nodeSetPtr = result->nodesetval;
	
	if (xmlXPathNodeSetIsEmpty(nodeSetPtr)) 
	{
		xmlXPathFreeObject(result);
		NSLog(@"%@",@"nodeset is empty");
		return NO;
	}
	
	xmlNodePtr nodePtr = nodeSetPtr->nodeTab[0];   
	xmlNodeSetContent(nodePtr, BAD_CAST [strValue UTF8String] );
	return YES;
}

- (BOOL) saveXmlFile
{
	if (m_pDoc == NULL || [m_strFilePath isEqualToString:@""])
	{
		return NO;
	}
	
	int nRel = xmlSaveFormatFileEnc([m_strFilePath UTF8String],m_pDoc,"GB2312",1);
	if (nRel == -1)
	{
		return NO;
	}
	return YES;
}


#pragma mark -
+ (NSString*)DocumentFilePath:(NSString*)strFileName
{
	NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
	NSString* docDir = [paths objectAtIndex:0];
	NSString* plistPath = [docDir stringByAppendingPathComponent:strFileName];
	if ([[NSFileManager defaultManager] fileExistsAtPath:plistPath] == NO) 
	{
		NSString *pathString = [[NSBundle mainBundle] resourcePath];
		return pathString;
	}
	return plistPath;
	
}
@end


#pragma mark -
@implementation LibXmlEx (private)
- (int) code_convert:(char*)from_charset to:(char*)to_charset inBuffer:(char*)inbuf
            inLength:(int)inlen outBuffer:(char*)outbuf outLength:(int)outlen
{
    iconv_t cd;
    char** pin = &inbuf;
    char** pout = &outbuf;
	size_t* pinlen = (size_t*)&inlen;
	size_t* poutlen = (size_t*)&outlen;
    
    cd = iconv_open(to_charset, from_charset);
    if (0 == cd) {
        return -1;
    }
    memset(outbuf,0,outlen);
    if (-1 == iconv(cd, pin,pinlen, pout,poutlen)) {
        return -1;
    }
    iconv_close(cd);
    return 0;
}

- (char*) u2g:(char*)inbuf
{
    int nOutLen = 2*strlen(inbuf) + 1;
    char *szOut = (char*)malloc(nOutLen);
    
    if (-1 ==[self code_convert:"utf-8" to:"gb2312" inBuffer:inbuf
                       inLength:strlen(inbuf) outBuffer:szOut outLength:nOutLen]) {
        free(szOut);
        szOut = NULL;
    }
    return szOut;
}
- (char*) g2u:(char*)inbuf
{
    int nOutLen = 2*strlen(inbuf) + 1;
    char *szOut = (char*)malloc(nOutLen);
    
    if (-1 ==[self code_convert:"gb2312" to:"utf-8" inBuffer:inbuf
                       inLength:strlen(inbuf) outBuffer:szOut outLength:nOutLen]) {
        free(szOut);
        szOut = NULL;
    }
    return szOut;
}

- (xmlXPathObjectPtr) get_nodeset:(xmlChar*)xpath
{
    xmlXPathContextPtr context;
    xmlXPathObjectPtr result;
    
    context = xmlXPathNewContext(m_pDoc);
    if (NULL == context) {
        NSLog(@"%@",@"xmlXPathNewContext return NULL");
        return NULL;
    }
    
    result = xmlXPathEvalExpression(xpath, context);
    xmlXPathFreeContext(context);
    if (NULL == result) {
        NSLog(@"%@",@"xmlXPathEvalExpression return NULL");
        return NULL;
    }
    
    if (xmlXPathNodeSetIsEmpty(result->nodesetval)) {
        NSLog(@"%@",@"xmlXPathNodeSetIsEmpty");
        return NULL;
    }
    return result;
}


@end