/// <summary>
/// Attempts to load all secret values for the specified object.
/// </summary>
/// <param name="obj">
/// The object where secret values will be loaded.
/// </param>
static public void LoadSecrets(object obj)
{
// Validate
if (obj == null)
{
throw new ArgumentNullException(nameof(obj));
}
// Get all fields
FieldInfo[] fields = obj.GetType().GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
// Look for secret fields
foreach (var field in fields)
{
// Try to get attribute
SecretValueAttribute sva = field.GetCustomAttribute <SecretValueAttribute>();
// If not a secret, skip
if (sva == null)
{
continue;
}
// Try to load the value
TryLoadValue(sva, field, obj);
}
}
/// <summary>
/// Attempts to load a secret value into the specified field.
/// </summary>
/// <param name="sva">
/// A <see cref="SecretValueAttribute"/> that indicates the source of the secret value.
/// </param>
/// <param name="field">
/// The field where the value will be loaded.
/// </param>
/// <param name="obj">
/// The object instance where the value will be set.
/// </param>
/// <param name="overwrite">
/// <c>true</c> to overwrite non-default values; otherwise <c>false</c>. The default is <c>false</c>.
/// </param>
/// <remarks>
/// By default <see cref="SecretHelper"/> will only update fields that are set to default values
/// (e.g. 0 for int and null or "" for string). This allows values set in the Unity inspector to
/// override values stored in the environment. If values in the environment should always take
/// precedence over values stored in the field set <paramref name="overwrite"/> to <c>true</c>.
/// </remarks>
static private void TryLoadValue(SecretValueAttribute sva, FieldInfo field, object obj, bool overwrite = false)
{
// Validate
if (sva == null)
{
throw new ArgumentNullException(nameof(sva));
}
if (field == null)
{
throw new ArgumentNullException(nameof(field));
}
if (obj == null)
{
throw new ArgumentNullException(nameof(obj));
}
// Now get the current value of the field
object curValue = field.GetValue(obj);
// If we're not overwriting values, we need to check to check and make sure a non-default value is not already set
if (!overwrite)
{
// What is the default value for the field?
object defValue = GetDefaultValue(field.FieldType);
// Is it the current value the same as the default value?
bool isDefaultValue = ((curValue == defValue) || ((field.FieldType == typeof(string)) && (string.IsNullOrEmpty((string)curValue))));
// If the current value is not the default value, the secret has already been supplied
// and we don't need to do any more work.
if (!isDefaultValue)
{
return;
}
}
// Either in overwrite mode or a default value. Let's try to read the environment variable.
string svalue = Environment.GetEnvironmentVariable(sva.Name);
// Check for no environment variable or no value set.
if (string.IsNullOrEmpty(svalue))
{
Debug.LogWarning($"{obj.GetType().Name}.{field.Name} has the default value '{curValue}' but the environment variable {sva.Name} is missing or not set.");
return;
}
// If string, just assign. Otherwise attempt to convert.
if (field.FieldType == typeof(string))
{
field.SetValue(obj, svalue);
}
else
{
try
{
object cvalue = Convert.ChangeType(svalue, field.FieldType);
field.SetValue(obj, cvalue);
}
catch (Exception ex)
{
Debug.LogWarning($"The value '{svalue}' of environment variable {sva.Name} could not be converted to {field.FieldType.Name}. {ex.Message}");
}
}
}
