private void ConfigureFromFile()

in src/log4net/Config/XmlConfiguratorAttribute.cs [236:307]
62 lines of code
12 McCabe index (conditional complexity)

		private void ConfigureFromFile(Assembly sourceAssembly, ILoggerRepository targetRepository)
		{
			// Work out the full path to the config file
			string fullPath2ConfigFile = null;
			
			// Select the config file
			if (m_configFile == null || m_configFile.Length == 0)
			{
				if (m_configFileExtension == null || m_configFileExtension.Length == 0)
				{
					// Use the default .config file for the AppDomain
					try
					{
						fullPath2ConfigFile = SystemInfo.ConfigurationFileLocation;
					}
					catch(Exception ex)
					{
						LogLog.Error(declaringType, "XmlConfiguratorAttribute: Exception getting ConfigurationFileLocation. Must be able to resolve ConfigurationFileLocation when ConfigFile and ConfigFileExtension properties are not set.", ex);
					}
				}
				else
				{
					// Force the extension to start with a '.'
					if (m_configFileExtension[0] != '.')
					{
						m_configFileExtension = "." + m_configFileExtension;
					}

					string applicationBaseDirectory = null;
					try
					{
						applicationBaseDirectory = SystemInfo.ApplicationBaseDirectory;
					}
					catch(Exception ex)
					{
						LogLog.Error(declaringType, "Exception getting ApplicationBaseDirectory. Must be able to resolve ApplicationBaseDirectory and AssemblyFileName when ConfigFileExtension property is set.", ex);
					}

					if (applicationBaseDirectory != null)
					{
						fullPath2ConfigFile = Path.Combine(applicationBaseDirectory, SystemInfo.AssemblyFileName(sourceAssembly) + m_configFileExtension);
					}
				}
			}
			else
			{
				string applicationBaseDirectory = null;
				try
				{
					applicationBaseDirectory = SystemInfo.ApplicationBaseDirectory;
				}
				catch(Exception ex)
				{
					LogLog.Warn(declaringType, "Exception getting ApplicationBaseDirectory. ConfigFile property path ["+m_configFile+"] will be treated as an absolute path.", ex);
				}

				if (applicationBaseDirectory != null)
				{
					// Just the base dir + the config file
					fullPath2ConfigFile = Path.Combine(applicationBaseDirectory, m_configFile);
				}
				else
				{
					fullPath2ConfigFile = m_configFile;
				}
			}

			if (fullPath2ConfigFile != null)
			{
				ConfigureFromFile(targetRepository, new FileInfo(fullPath2ConfigFile));
			}
		}