private void ConfigureFromFile()

in src/log4net/Config/XmlConfiguratorAttribute.cs [206:277]
62 lines of code
10 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 (string.IsNullOrEmpty(ConfigFile))
    {
      if (string.IsNullOrEmpty(ConfigFileExtension))
      {
        // Use the default .config file for the AppDomain
        try
        {
          fullPath2ConfigFile = SystemInfo.ConfigurationFileLocation;
        }
        catch (Exception e) when (!e.IsFatal())
        {
          LogLog.Error(_declaringType, "XmlConfiguratorAttribute: Exception getting ConfigurationFileLocation. Must be able to resolve ConfigurationFileLocation when ConfigFile and ConfigFileExtension properties are not set.", e);
        }
      }
      else
      {
        // Force the extension to start with a '.'
        if (ConfigFileExtension![0] != '.')
        {
          ConfigFileExtension = '.' + ConfigFileExtension;
        }

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

        if (applicationBaseDirectory is not null)
        {
          fullPath2ConfigFile = Path.Combine(applicationBaseDirectory, SystemInfo.AssemblyFileName(sourceAssembly) + ConfigFileExtension);
        }
      }
    }
    else
    {
      string? applicationBaseDirectory = null;
      try
      {
        applicationBaseDirectory = SystemInfo.ApplicationBaseDirectory;
      }
      catch (Exception e) when (!e.IsFatal())
      {
        LogLog.Warn(_declaringType, $"Exception getting ApplicationBaseDirectory. ConfigFile property path [{ConfigFile}] will be treated as an absolute path.", e);
      }

      if (applicationBaseDirectory is not null)
      {
        // Just the base dir + the config file
        fullPath2ConfigFile = Path.Combine(applicationBaseDirectory, ConfigFile!);
      }
      else
      {
        fullPath2ConfigFile = ConfigFile;
      }
    }

    if (fullPath2ConfigFile is not null)
    {
      ConfigureFromFile(targetRepository, new FileInfo(fullPath2ConfigFile));
    }
  }