LibXML2 Sax分析和&符号 [英] LibXML2 Sax Parsing and ampersand

问题描述

我遇到（我认为是）使用sax解析器时的一个奇怪的行为，我想知道是否正常。

I've encountered (what I think is) a strange behavior when using the sax parser, and I wanted to know if it's normal.

我正在发送这个XML通过SAX解析器：

I'm sending this XML through the SAX parser:

<site url="http://example.com/?a=b&amp;b=c"; />

&当 startElement 回调
被调用时，转换为&。应该这样做吗？如果是这样，我想要
了解为什么。

The "&" gets converted to " &" when the startElement callback is called. Is it supposed to do that? If so, I would like to understand why.

我已经粘贴了一个示例，说明了这个问题：

I've pasted an example demonstrating the issue here:

#include <stdlib.h>
#include <libxml/parser.h>

static void start_element(void * ctx, const xmlChar *name, const xmlChar **atts)
{
  int i = 0;
  while(atts[i] != NULL) {
    printf("%s\n", atts[i]);
    i++;
  }
}

int main(int argc, char *argv[]) {
  xmlSAXHandlerPtr handler = calloc(1, sizeof(xmlSAXHandler));
  handler->startElement = start_element;

  char * xml = "<site url=\"http://example.com/?a=b&amp;b=c\" />";

  xmlSAXUserParseMemory( handler,
                          NULL,
                          xml,
                          strlen(xml)
  );
}

PS：此消息实际上是从 LibXML2列表 ...我不是这封邮件的初始作者，但我注意到使用 Nokogiri 和 Aaron （Nokogiri的维护者）实际上自己发布了这个消息。

PS: This message is actually extracted from the LibXML2 list... and I am not the initial author of this mail, but I noticed the problem using Nokogiri and Aaron (the maintainer of Nokogiri) actually posted this message himself.

推荐答案

这个消息描述了同样的问题（我也有）和回复对

This message describes the same problem (which I had as well) and the response says to

请求解析器替换实体值

ask the parser to replace entities values

意思是当您设置您的上下文时，设置如下选项：

What that means is when you are setting up your context, set the option like this:

xmlParserCtxtPtr context = xmlCreatePushParserCtxt(&yourSAXHandlerStruct, self, NULL, 0, NULL);
xmlCtxtUseOptions(context, XML_PARSE_NOENT);

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