September 25, 2007
Straightforward SettingsInitialization
This is the part where you set where each of your settings are kept—the storages, that is. It's quite simple: you define the function ss::init_settings, and in its body, add storages. For each added storage, you specify the name_root, and the type of storage.
Any name that starts with name_root (it's of type "name_root.subname") belongs to the given storage. See Listing Seven.
void ss::init_settings() {
def_cfg().add_storage("", file_storage("app.ini");
def_cfg().add_storage("user", registry_storage("CU/Software/MyApp/user");
def_cfg().add_storage("chart", registry_storage("CU/Software/MyApp/chart");
}
// Some settings:
// app.retries - from app.ini file
// user.name - from registry
// user.passw - from registy
// chart.buffer_size - from registry
// chart.window.width - from registry
// chart.window.height - from registry
// tmp.del_period - from app.ini file
Listing Seven
Once you've defined ss::init_settings, the library will do its thing. You'll love the fact that configuring the storages is just 2-3 lines of code. Even more, you can have multiple configurations—on each configuration, read the settings from somewhere else. For instance, on debug mode, read the settings from an .ini file, in release mode, read the settings from the registry. This is a great aid when debugging— it's much simpler to edit a file than the registry. Besides, it's much easier to test multiple configurations. Just have different versions of the .ini file (or, select the name of the configuration file through a command line argument. Why not?). Just think how complicated that would be if you were to deal with the registry directly!
As said, you define ss::init_settings, and specify where the settings are kept. Here's my favorite: if the current directory (or some specific directory) contains a somefilename.ini file, read the settings from there. Otherwise, read the settings from the registry. Usually, for me, this means: in debug mode, I deal with an .ini file—easily modifiable. As a matter of fact, it's part of the (VC) project's files. In release, I deal with the registry. However, if I run into problems in release mode, I can easily duplicate the debug configuration (simply copy the .ini file where I need it) and vice-versa (just remove or rename the .ini file). 
Previous Page |
1 Usability: More than Meets the Eye
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2 Runtime Constants
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3 Initialization
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4 Defaults
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