XMLAttributeParser.h

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#pragma once
 
#include <cstring>
#include "basic/Str.h"
 
namespace tiny_dlna {
 
class XMLAttributeParser {
 public:
  static bool extractAttribute(const char* xml, const char* tagName,
                               const char* attrName, char* outBuf,
                               size_t bufSize) {
    if (!xml || !tagName || !attrName || !outBuf || bufSize == 0) return false;
    const char* p = strstr(xml, tagName);
    while (p) {
      const char* tagEnd = strchr(p, '>');
      if (!tagEnd) return false;
      const char* attrPos = strstr(p, attrName);
      if (attrPos && attrPos < tagEnd) {
        const char* q = strchr(attrPos, '"');
        if (!q || q > tagEnd) return false;
        q++;
        const char* qend = strchr(q, '"');
        if (!qend || qend > tagEnd) return false;
        size_t vlen = (size_t)(qend - q);
        size_t copyLen = vlen < (bufSize - 1) ? vlen : (bufSize - 1);
        if (copyLen > 0) memcpy(outBuf, q, copyLen);
        outBuf[copyLen] = '\0';
        return true;
      }
      p = strstr(p + 1, tagName);
    }
    return false;
  }
 
  static bool extractAttributeToken(const char* xml, const char* tagName,
                                     const char* attrName, int n,
                                     char* outBuf, size_t bufSize) {
    if (!xml || !tagName || !attrName || n <= 0 || !outBuf || bufSize == 0) return false;
    char proto[256] = {0};
    bool ok = extractAttribute(xml, tagName, attrName, proto, sizeof(proto));
    if (!ok || proto[0] == '\0') return false;
    // proto format: token1:token2:token3:token4
    int col = 1;
    const char* tokenStart = proto;
    if (n > 1) {
      for (size_t i = 0; proto[i] != '\0'; ++i) {
        if (proto[i] == ':') {
          ++col;
          if (col == n) {
            tokenStart = proto + i + 1;
            break;
          }
        }
      }
    }
    if (!tokenStart || *tokenStart == '\0') return false;
    // copy token into outBuf until ':' or end
    size_t j = 0;
    for (; tokenStart[j] != '\0' && tokenStart[j] != ':' && j + 1 < bufSize; ++j) outBuf[j] = tokenStart[j];
    outBuf[j] = '\0';
    return outBuf[0] != '\0';
  }
};
 
} // namespace tiny_dlna