utils.cpp

#include "utils.h"

// ========================================================================================================
// URL Decode
// See: https://circuits4you.com/2019/03/21/esp8266-url-encode-decode-example/
// ========================================================================================================
String urldecode(String str){
    String encodedString="";
    char c;
    char code0;
    char code1;
    for (int i =0; i < str.length(); i++){
        c=str.charAt(i);
      if (c == '+'){
        encodedString+=' ';  
      }else if (c == '%') {
        i++;
        code0=str.charAt(i);
        i++;
        code1=str.charAt(i);
        c = (h2int(code0) << 4) | h2int(code1);
        encodedString+=c;
      } else{
        
        encodedString+=c;  
      }
      
      yield();
    }
    
   return encodedString;
}

unsigned char h2int(char c){
    if (c >= '0' && c <='9'){
        return((unsigned char)c - '0');
    }
    if (c >= 'a' && c <='f'){
        return((unsigned char)c - 'a' + 10);
    }
    if (c >= 'A' && c <='F'){
        return((unsigned char)c - 'A' + 10);
    }
    return(0);
}

// ========================================================================================================
// Tokenizing strings
// See: https://forum.arduino.cc/t/how-to-split-a-string-with-space-and-store-the-items-in-array/888813/8
// ========================================================================================================
bool get_token(String &from, String &to, uint8_t index, char separator)
{
  uint16_t start = 0, idx = 0;
  uint8_t cur = 0;
  while (idx < from.length())
  {
    if (from.charAt(idx) == separator)
    {
      if (cur == index)
      {
        to = from.substring(start, idx);
        return true;
      }
      cur++;
      while ((idx < from.length() - 1) && (from.charAt(idx + 1) == separator)) idx++;
      start = idx + 1;
    }
    idx++;
  }
  if ((cur == index) && (start < from.length()))
  {
    to = from.substring(start, from.length());
    return true;
  }
  return false;
}