Configuration#

Situation#

An application quickly has various sets of configuration settings, from user details and server access to application-specific preferences. Adding them should just be a definition of what is needed. However, several details typically increase the effort:

Protection from wrong entries to ensure valid values
A predictable way to find them in the application including ways to display and edit them (UI)
Storage and, eventually, secure storage of sensitive settings like passwords for server access (persistency, security)
Shipping configuration settings and maintaining them (data exchange)

The bottom line: a configuration setting is not a big thing on its own, but it grows in complexity due to the impact from other concerns.

Approach#

APPXC introduces a Setting class to hold separate values with various predefined types for integer, string, email or password. The class utilizes a conversion function to convert an original entry to a valid value. This separation enables:

validity checks
displaying the original entry in the UI
providing only valid values to functions using the setting

A class SettingDict is added to maintain sets of configuration settings and a class Config is added to maintain all configuration settings in one object.

Incomplete

A typical example to set up a configuration, given an application harness, still needs to be added. Similarly, corresponding modules must be linked.