Config

1. Purpose

The DTSConfig class provides a centralized, thread-safe mechanism for loading and accessing an alternate application configuration file (e.g., for plugin-specific or test-specific configs), overriding the default app.config/web.config. It enables runtime configuration of the config file path via DTSConfigInit, then exposes typed accessors (GetAppSetting, GetSection) to read settings and custom sections from that alternate file using .NET’s System.Configuration APIs. This supports scenarios like plugin isolation or environment-specific overrides without modifying the main executable’s config.

2. Public Interface

static void DTSConfigInit(string path)
Initializes the alternate configuration by setting the config file path and loading the configuration. Internally calls SetAltConfigPath(path). If path is null or empty, falls back to DTSConstants.CustomConfigPath. Must be called before other config accessors to ensure AltConfig is populated.
static string GetAppSetting(string key)
Retrieves the value of an <add key="..." value="..."/> entry from the appSettings section of the alternate configuration. Returns string.Empty if the key is not found. Logs a warning via APILogger when the key is absent.
static object GetSection(string sectionName)
Retrieves a custom configuration section (e.g., <section name="..." type="..." />) by name from the alternate configuration. Returns null if the section is not defined. Logs a warning via APILogger when the section is absent.
static string AltConfigPathGet()
Thread-safe getter for the current alternate config file path (stored in AltConfigPath). Returns the path string (may be null or empty if not set or reset).
static void AltConfigPathSet(string path)
Thread-safe setter for the alternate config file path. Updates AltConfigPath but does not reload the configuration—SetAltConfigPath must be called to apply the new path and reinitialize AltConfig.

3. Invariants

Thread Safety: All access to AltConfigPath and AltConfig is guarded by a private static lock object (MyLock). Reads (AltConfigPathGet, GetAltConfig, GetAppSetting, GetSection) and writes (AltConfigPathSet, SetAltConfigPath) are serialized.
Fallback Behavior: When AltConfigPath is null or empty, SetAltConfigPath uses DTSConstants.CustomConfigPath as the config file path.
Configuration Loading: AltConfig is lazily initialized on first call to SetAltConfigPath (via DTSConfigInit or direct invocation) and not reloaded automatically on subsequent path changes—SetAltConfigPath must be called again to refresh it.
Error Handling: Missing keys/sections are not thrown as exceptions; instead, they return string.Empty/null with a log message. No fallback to default config is attempted.

4. Dependencies

Internal Dependencies:
- DTS.Common.Utilities.Logging.APILogger — Used for logging missing config entries/sections.
- System.Configuration.ConfigurationManager, ExeConfigurationFileMap, ConfigurationUserLevel — For loading and accessing configuration files.
- DTSConstants.CustomConfigPath — Fallback path when AltConfigPath is unset.
External Dependencies:
- System.Configuration assembly (standard .NET Framework/Standard).
- No direct runtime dependencies beyond .NET config APIs.
Depended Upon By:
- Plugin code (per GetSection’s XML comment) to access plugin-specific configuration sections.
- Any module requiring runtime-configurable settings without modifying the main executable’s config.

5. Gotchas

AltConfigPathSet does not reload config: Calling AltConfigPathSet alone updates the stored path but does not reinitialize AltConfig. The configuration must be reloaded via SetAltConfigPath (e.g., DTSConfigInit) to apply changes.
No fallback to main config: If the alternate config file is missing, invalid, or lacks a requested key/section, the system logs a warning but returns string.Empty/null—it does not fall back to the default app.config.
DTSConstants.CustomConfigPath is assumed but not defined here: The fallback path relies on an external constant (DTSConstants.CustomConfigPath). Its value and behavior are not visible in this file.
Thread-safety only covers state, not config validity: While access to AltConfig is thread-safe, concurrent calls to SetAltConfigPath may cause transient inconsistencies (e.g., one thread sets a path while another reads AltConfig before reinitialization completes).
No validation of config file path: SetAltConfigPath does not validate whether the provided path exists or is readable; ConfigurationManager.OpenMappedExeConfiguration will throw if the file is inaccessible (e.g., FileNotFoundException), but this is not handled internally.

5.1 KiB Raw Blame History Unescape Escape