external/CLI/ConfigFwd.hpp

0001 // Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
0002 // under NSF AWARD 1414736 and by the respective contributors.
0003 // All rights reserved.
0004 //
0005 // SPDX-License-Identifier: BSD-3-Clause
0006
0007 #pragma once
0008
0009 // [CLI11:public_includes:set]
0010 #include <algorithm>
0011 #include <fstream>
0012 #include <iostream>
0013 #include <string>
0014 #include <vector>
0015 // [CLI11:public_includes:end]
0016
0017 #include "Error.hpp"
0018 #include "StringTools.hpp"
0019
0020 namespace CLI {
0021 // [CLI11:config_fwd_hpp:verbatim]
0022
0023 class App;
0024
0025 /// Holds values to load into Options
0026 struct ConfigItem {
0027     /// This is the list of parents
0028     std::vector<std::string> parents{};
0029
0030     /// This is the name
0031     std::string name{};
0032
0033     /// Listing of inputs
0034     std::vector<std::string> inputs{};
0035
0036     /// The list of parents and name joined by "."
0037     std::string fullname() const {
0038         std::vector<std::string> tmp = parents;
0039         tmp.emplace_back(name);
0040         return detail::join(tmp, ".");
0041     }
0042 };
0043
0044 /// This class provides a converter for configuration files.
0045 class Config {
0046   protected:
0047     std::vector<ConfigItem> items{};
0048
0049   public:
0050     /// Convert an app into a configuration
0051     virtual std::string to_config(const App *, bool, bool, std::string) const = 0;
0052
0053     /// Convert a configuration into an app
0054     virtual std::vector<ConfigItem> from_config(std::istream &) const = 0;
0055
0056     /// Get a flag value
0057     virtual std::string to_flag(const ConfigItem &item) const {
0058         if(item.inputs.size() == 1) {
0059             return item.inputs.at(0);
0060         }
0061         throw ConversionError::TooManyInputsFlag(item.fullname());
0062     }
0063
0064     /// Parse a config file, throw an error (ParseError:ConfigParseError or FileError) on failure
0065     std::vector<ConfigItem> from_file(const std::string &name) {
0066         std::ifstream input{name};
0067         if(!input.good())
0068             throw FileError::Missing(name);
0069
0070         return from_config(input);
0071     }
0072
0073     /// Virtual destructor
0074     virtual ~Config() = default;
0075 };
0076
0077 /// This converter works with INI/TOML files; to write INI files use ConfigINI
0078 class ConfigBase : public Config {
0079   protected:
0080     /// the character used for comments
0081     char commentChar = '#';
0082     /// the character used to start an array '\0' is a default to not use
0083     char arrayStart = '[';
0084     /// the character used to end an array '\0' is a default to not use
0085     char arrayEnd = ']';
0086     /// the character used to separate elements in an array
0087     char arraySeparator = ',';
0088     /// the character used separate the name from the value
0089     char valueDelimiter = '=';
0090     /// the character to use around strings
0091     char stringQuote = '"';
0092     /// the character to use around single characters
0093     char characterQuote = '\'';
0094
0095   public:
0096     std::string
0097     to_config(const App * /*app*/, bool default_also, bool write_description, std::string prefix) const override;
0098
0099     std::vector<ConfigItem> from_config(std::istream &input) const override;
0100     /// Specify the configuration for comment characters
0101     ConfigBase *comment(char cchar) {
0102         commentChar = cchar;
0103         return this;
0104     }
0105     /// Specify the start and end characters for an array
0106     ConfigBase *arrayBounds(char aStart, char aEnd) {
0107         arrayStart = aStart;
0108         arrayEnd = aEnd;
0109         return this;
0110     }
0111     /// Specify the delimiter character for an array
0112     ConfigBase *arrayDelimiter(char aSep) {
0113         arraySeparator = aSep;
0114         return this;
0115     }
0116     /// Specify the delimiter between a name and value
0117     ConfigBase *valueSeparator(char vSep) {
0118         valueDelimiter = vSep;
0119         return this;
0120     }
0121     /// Specify the quote characters used around strings and characters
0122     ConfigBase *quoteCharacter(char qString, char qChar) {
0123         stringQuote = qString;
0124         characterQuote = qChar;
0125         return this;
0126     }
0127 };
0128
0129 /// the default Config is the TOML file format
0130 using ConfigTOML = ConfigBase;
0131
0132 /// ConfigINI generates a "standard" INI compliant output
0133 class ConfigINI : public ConfigTOML {
0134
0135   public:
0136     ConfigINI() {
0137         commentChar = ';';
0138         arrayStart = '\0';
0139         arrayEnd = '\0';
0140         arraySeparator = ' ';
0141         valueDelimiter = '=';
0142     }
0143 };
0144 // [CLI11:config_fwd_hpp:end]
0145 }  // namespace CLI