Files
NSPanel_HA_Blueprint/components/nspanel_ha_blueprint/text.h
Edward Firmo d5f5a3eaaf User defined decimal separator for values
Partially solves #1161
2024-02-27 10:32:06 +01:00

101 lines
4.2 KiB
C++

// text.h
#pragma once
#include <algorithm>
#include <cctype>
#include <cstring>
#include <string>
namespace nspanel_ha_blueprint {
/**
* Copies the contents of a std::string to a fixed-size char array, ensuring
* null termination of the string within the array. This function template
* automatically deduces the size of the destination char array at compile time,
* minimizing the risk of buffer overflow. It's designed for use with fixed-size
* char arrays only, not pointers or dynamically allocated memory.
*
* Template Parameter:
* N - The size of the destination char array. This value is deduced automatically
* and must be greater than 0.
*
* Parameters:
* dest - A reference to the destination char array where the string should be copied.
* The array must have a size that can accommodate the source string plus a
* null terminator. If the source string is longer than the destination array,
* it will be truncated.
* src - The source std::string to copy. This string's contents are copied into the
* destination array up to the array's capacity minus one, to leave space for
* the null terminator.
*
* Usage Example:
* char destination[11];
* std::string source = "Hello";
* nspanel_ha_blueprint::copyStringToCharArray(destination, source);
*
* Note: The destination array is always null-terminated, even if the source string
* is truncated to fit into the array.
*/
template <unsigned int N>
void copyStringToCharArray(char (&dest)[N], const std::string& src) {
// Ensure we do not exceed the buffer size, leaving space for the null terminator
size_t length = std::min(src.size(), N - 1);
// Copy the string data into the destination buffer
std::strncpy(dest, src.c_str(), length);
// Explicitly null-terminate the destination buffer
dest[length] = '\0';
}
// Helper function to determine if a character is part of a number
bool isNumberChar(char c) {
return std::isdigit(c) || c == '.' || c == '-' || c == ',';
}
/**
* Adjusts the decimal separator in a numeric string to a specified character.
* This function identifies and modifies the decimal separator of a number within a string,
* ensuring that only the first occurrence is replaced if it is a valid number followed by
* any non-numeric characters (e.g., units of measurement). If the input string does not
* start with a valid number, it is returned unchanged.
*
* @param input The string potentially containing a numeric value followed by text.
* @param decimalSeparator The character to use as the decimal separator.
* @return A string with the decimal separator adjusted if the input is a valid number,
* otherwise the original input string.
*/
std::string adjustDecimalSeparator(const std::string& input, char decimalSeparator) {
// Immediately return the original string if the desired decimal separator is "."
if (decimalSeparator == '.') {
return input;
}
// Find the end of the numeric part of the string
size_t numericEnd = 0;
for (; numericEnd < input.size() && isNumberChar(input[numericEnd]); ++numericEnd);
// Extract the numeric part and the suffix (if any)
std::string numericPart = input.substr(0, numericEnd);
std::string suffix = input.substr(numericEnd);
// Attempt to convert the numeric part to a double
char* end;
double val = strtod(numericPart.c_str(), &end);
// Check if conversion was successful (end points to a null terminator if so)
if (end != numericPart.c_str() && *end == '\0') {
// Find and replace only the first occurrence of '.' with the specified decimalSeparator
size_t decimalPointPos = numericPart.find('.');
if (decimalPointPos != std::string::npos) {
numericPart[decimalPointPos] = decimalSeparator;
}
return numericPart + suffix;
} else {
// If the input is not a number, return it as is
return input;
}
}
} // namespace nspanel_ha_blueprint