A header only library to inherit from: Supports saving member variables to file and loading from file. It uses tinyxml2. The files can be edited and thus variables can be changed without the need to rebuild.

Basically you have to register the member variables only once in the constructor. Thats it. Save to file or load from file by calling the methodes (see below).

You can define a sanity check function for the variable.

• bool
• int
• unsigned int
• float
• double
• std::string // strings longer than 200 characters will be cropped!! see *src/tinyxml2/tinyxml2.h BUF_SIZE;
• arrays and (const size) vectors of thouse types
• In generel every class/structure where the members are stored tightly packed in an array like:
  • Eigen: put<double, 3>(eigen_vactor3d.x(), "eigen_vector3d")
  • glm: put<float, 3>(glm_vec3[0], "glm_vec3d")
• You can easily add support for other types or even structs by provideing parser from and to that type. search for <TYPE_SUPPORT> in include/settings.hpp to find all places where you have to add some functionality.

• tinyxml2. (included as submodule)

1. Clone the repository and update the submodule
   • git clone ...
   • cd settings
   • git submodule update --init --recursive
2. (This step is not necessary) To avoid getting flodded with warnings from tinyxml2 I recomend to install it
   • cd src/tinyxml2/ && mkdir build && cd build
   • cmake -DCMAKE_BUILD_TYPE=RELEASE ..
   • sudo make install
3. Include the library (header only) using the provided CMakeLists.txt or just include the relative path:
   • e.g: #include "settings/include/settings.hpp"
4. (This step is not necessary) There is a bash script to build and run the unit tests for tinyxml2 and the Settings class.
   • requires boost to be installed (works with 1.65.1)
   • ./buildAndRunTests.sh
5. (This step is not necessary) There is an example in example.cpp.
   • build it: g++ -std=gnu++17 src/tinyxml2/tinyxml2.cpp example.cpp -o run_example
   • have a look at it
   • then run it with ./run_example
6. Make sure to define yor local environment using #include <local.h>. E.g defining std::locale("C"); To make sure that floating point numbers always get stored with the same decimal seperator. Otherwise different environments might use different seperators!

• The following functions throw runtime errors (Happens when parsing xml file goes wrong.)
  • put<T>(T&, std::string&, bool) here the throw can be supressed setting bool to true. Happens if the file had an entry of that variable but was not able to read it. If supressed or catched, the member will have its default value.
  • reloadAllFromFile(). Will try to load every found member variable in the file given before. Throws if at least one variable was found (had an entry) but could not be parsed. If you catch and continue, all variables which could be parsed will have the parsed value, others will have their old value.
  • reloadAllFromFile("path/to/data.xml"). Will try to load every found member variable in the given file. Throws if at least one variable was found (had an entry) but could not be parsed. If you catch and continue, all variables which could be parsed will have the parsed value, others will have their old value.
  • save(). Will throw if the file given before could not be parsed or written. If you catch, you should probably not use the file if it got created.
  • save("path/to/data.xml"). Will throw if the file could not be parsed or written. If you catch, you should probably not use the file if it got created.
  • deleteFile(). Uses std::filesystem to delete the xml file storing the classes data. This might throw an exception on underlying OS API errors.
  • moveFile(). Uses std::filesystem to move the xml file storing the classes data. This might throw an exception on underlying OS API errors.

// Have a sanity check (not necessarry)
template <class T>
void mustBeAtLeast(T& var, T min){
	if(var < min){
		var = min;
	}
}

// inherit from Settings
class YourClass : public util::Settings{...

// have a member variable
double height = 200.;
static constexpr double MIN_HEIGHT = 10.;


YourClass() {
	// inside your class constructor mark the variable to be stored
	// EITHER LIKE THIS
	put(height, "unique_key_height");
	// OR LIKE THIS WITH SANITY CHECK
	put(height, "unique_key_height", mustBeAtLeast, MIN_HEIGHT); 
	// If the settings file already existed and had an entry <unique_key_height>...</unique_key_height> 
	// this->height will now hold that value
	
	// If a sanity function is provided, that function will be called on every load from config and every save to config.
	...
	}
...
};
	
// Somewhere outside the class:
YourClass your_class("settings/YourClass.xml");
// You can trigger to save all the current values into the config with
your_class.save("path/to/file"); // path to file must be given only once

// You can force a reload of all values from config with
your_class.reloadAllFromFile();