KeyValuePrinter Class Reference

create human-readable or JSON output for key value pairs. More...

#include <KeyValuePrinter.h>

Collaboration diagram for KeyValuePrinter:

Public Member Functions
	KeyValuePrinter (bool use_json, unsigned key_max_length=10)
	Ctor.
std::string	string () const
	Return completed string.
template<class T >
void	put (const std::string &key, const T &value)
	Add one key-value pair.
template<class T >
void	put (const std::string &key, const std::map< std::string, T > &value)
	Specialization for map<>

Private Member Functions
std::string	escape (const std::string &value) const
	escape string.
std::string	escape (const char *value) const
	escape string literals.
template<class T >
std::string	escape (const T &value) const
	escape numeric value.
template<class T >
std::string	escape (const std::vector< T > &value) const
	escape vector<T>.
template<class T >
std::string	escape (const std::map< std::string, T > &value) const
	escape map<string, T>.

Private Attributes
bool	m_json
	create JSON output?
unsigned	m_maxpad
	for human-readable output: how much padding after key?
std::string	m_delim
	for JSON: comma to print after prev entry.
std::stringstream	m_stream
	output being built.

Detailed Description

create human-readable or JSON output for key value pairs.

Usage example for human-readable output:

KeyValuePrinter pr(false); //JSON=false
pr.put("a", 123);
pr.put("bbbbb", "string");
pr.put("ccccccc", std::vector<std::string>({"string", "abc"}));
std::cout << pr.string();
//which prints
// a:          123
// bbbbb:      string
// ccccccc:    [string, abc]

std::string, numeric types, std::vector<SUPPORTED TYPE>, and std::map<std::string, SUPPORTED TYPE> * are supported as value types for put().

JSON output is suitable for reading via e.g. json.loads() in Python, and performs the necessary escaping for strings. Compared to boost::property_tree::json_parser::write_json, KeyValuePrinter handles non-string types correctly.

Definition at line 46 of file KeyValuePrinter.h.

Constructor & Destructor Documentation

KeyValuePrinter()

KeyValuePrinter ( bool  use_json, unsigned  key_max_length = 10  )

inlineexplicit

Ctor.

Parameters

use_json	true for JSON output, false for human-readable output.
key_max_length	for human-readable output, this should be equal to strlen(longest_key) for aligning values in output.

Definition at line 53 of file KeyValuePrinter.h.

                                                                         :
      m_json(use_json),
      m_maxpad(key_max_length + 2),
      m_delim("")
    { }

~KeyValuePrinter()

~KeyValuePrinter ( )

inline

Definition at line 58 of file KeyValuePrinter.h.

{ }

Member Function Documentation

escape() [1/5]

std::string escape ( const char *  value ) const

inlineprivate

escape string literals.

Definition at line 102 of file KeyValuePrinter.h.

{ return escape(std::string(value)); }

escape() [2/5]

std::string escape ( const std::map< std::string, T > &  value ) const

inlineprivate

escape map<string, T>.

Definition at line 118 of file KeyValuePrinter.h.

    {
      //well, it's valid json, but not pretty
      KeyValuePrinter printer(m_json, m_maxpad - 2);
      for (auto pair : value)
        printer.put(pair.first, pair.second);
      return printer.string();
    }

escape() [3/5]

std::string escape ( const std::string &  value ) const

private

escape string.

Definition at line 14 of file KeyValuePrinter.cc.

{
  using namespace boost::property_tree::json_parser;
 
  if (m_json)
    return "\"" + create_escapes(value) + "\"";
  else
    return value;
}

escape() [4/5]

std::string escape ( const std::vector< T > &  value ) const

inlineprivate

escape vector<T>.

Definition at line 106 of file KeyValuePrinter.h.

    {
      std::string delim = "";
      std::string s = "[";
      for (auto el : value) {
        s += delim + escape(el);
        delim = ", ";
      }
      s += "]";
      return s;
    }

escape() [5/5]

std::string escape ( const T &  value ) const

inlineprivate

escape numeric value.

Definition at line 104 of file KeyValuePrinter.h.

{ return std::to_string(value); }

put() [1/2]

void put ( const std::string &  key, const std::map< std::string, T > &  value  )

inline

Specialization for map<>

Definition at line 79 of file KeyValuePrinter.h.

    {
      if (m_json) {
        m_stream << m_delim << "\t" << escape(key) << ": " << escape(value) << "";
      } else {
        m_stream << "\n" << key << "\n";
        for (char unused : key) {
          (void)unused;
          m_stream << '-';
        }
        m_stream << "\n" << escape(value) << "\n";
      }
      m_delim = ",\n";
    }

put() [2/2]

void put ( const std::string &  key, const T &  value  )

inline

Add one key-value pair.

Definition at line 69 of file KeyValuePrinter.h.

    {
      if (m_json) {
        m_stream << m_delim << "\t" << escape(key) << ": " << escape(value) << "";
      } else {
        m_stream << std::left << std::setw(m_maxpad) << key + ": " << escape(value) << "\n";
      }
      m_delim = ",\n";
    }

string()

std::string string ( ) const

inline

Return completed string.

Definition at line 61 of file KeyValuePrinter.h.

    {
      if (m_json)
        return "{\n" + m_stream.str() + "\n}\n";
      else
        return m_stream.str();
    }

Member Data Documentation

m_delim

std::string m_delim

private

for JSON: comma to print after prev entry.

Definition at line 96 of file KeyValuePrinter.h.

m_json

bool m_json

private

create JSON output?

Definition at line 94 of file KeyValuePrinter.h.

m_maxpad

unsigned m_maxpad

private

for human-readable output: how much padding after key?

Definition at line 95 of file KeyValuePrinter.h.

m_stream

std::stringstream m_stream

private

output being built.

Definition at line 97 of file KeyValuePrinter.h.

---

The documentation for this class was generated from the following files:

• framework/utilities/include/KeyValuePrinter.h
• framework/utilities/src/KeyValuePrinter.cc