/// <summary>
/// Creates a new <see cref="SnapshotValueSubscription"/> object.
/// </summary>
/// <param name="tag">The tag.</param>
/// <param name="onValueChange">The value change callback.</param>
internal SnapshotValueSubscription(TagDefinition tag, Action <TagValue> onValueChange)
{
_tag = tag ?? throw new ArgumentNullException(nameof(tag));
_onValueChange = onValueChange ?? throw new ArgumentNullException(nameof(onValueChange));
_tag._snapshotSubscriptions[this] = new object();
_tag.SnapshotValueSubscriptionChange?.Invoke(_tag);
}
/// <summary>
/// Tests if the specified identity is authorized to write tag data.
/// </summary>
/// <param name="tag">The tag.</param>
/// <param name="identity">The identity.</param>
/// <returns>
/// <see langword="true"/> if the caller is authorized, otherwise <see langword="false"/>.
/// </returns>
/// <exception cref="ArgumentNullException"><paramref name="tag"/> is <see langword="null"/>.</exception>
public static bool CanWrite(this TagDefinition tag, ClaimsPrincipal identity)
{
if (tag == null)
{
throw new ArgumentNullException(nameof(tag));
}
return(tag.IsAuthorized(identity, Tags.Security.TagSecurityPolicy.DataWrite, Tags.Security.TagSecurityPolicy.Administrator));
}
/// <summary>
/// Attempts to validate an incoming tag value.
/// </summary>
/// <param name="tag">The tag that the value is for.</param>
/// <param name="incoming">The incoming tag value.</param>
/// <param name="stateSet">
/// The state set for the tag. Can be <see langword="null"/> when the tag's data type is not
/// <see cref="TagDataType.State"/>.
/// </param>
/// <param name="validatedValue">The validated tag value.</param>
/// <returns>
/// <see langword="true"/> if the value could be validated, or <see langword="false"/> otherwise.
/// When the result is <see langword="false"/>, <paramref name="validatedValue"/> will be
/// <see langword="null"/>.
/// </returns>
internal static bool TryValidateIncomingTagValue(this TagDefinition tag, TagValue incoming, StateSet stateSet, out TagValue validatedValue)
{
if (tag == null)
{
throw new ArgumentNullException(nameof(tag));
}
if (incoming == null)
{
throw new ArgumentNullException(nameof(incoming));
}
bool result;
switch (tag.DataType)
{
case TagDataType.FloatingPoint:
result = TryValidateDoubleValue(tag, incoming, out validatedValue);
break;
case TagDataType.Integer:
result = TryValidateInt32Value(tag, incoming, out validatedValue);
break;
case TagDataType.Text:
result = TryValidateStringValue(tag, incoming, out validatedValue);
break;
case TagDataType.State:
result = TryValidateStateValue(tag, incoming, stateSet, out validatedValue);
break;
default:
validatedValue = null;
result = false;
break;
}
return(result);
}
/// <summary>
/// Attempts to validate an incoming floating-point tag value.
/// </summary>
/// <param name="tag">The tag for the value.</param>
/// <param name="originalValue">The incoming value.</param>
/// <param name="validatedValue">The validated value.</param>
/// <returns>
/// A flag that indicates if the value was validated.
/// </returns>
private static bool TryValidateDoubleValue(TagDefinition tag, TagValue originalValue, out TagValue validatedValue)
{
validatedValue = new TagValue(originalValue.UtcSampleTime, originalValue.NumericValue, Convert.ToString(originalValue.NumericValue, CultureInfo.InvariantCulture), originalValue.Quality, tag.Units);
return(true);
}
/// <summary>
/// Attempts to validate an incoming string tag value.
/// </summary>
/// <param name="tag">The tag for the value.</param>
/// <param name="originalValue">The incoming value.</param>
/// <param name="validatedValue">The validated value.</param>
/// <returns>
/// A flag that indicates if the value was validated.
/// </returns>
private static bool TryValidateStringValue(TagDefinition tag, TagValue originalValue, out TagValue validatedValue)
{
validatedValue = new TagValue(originalValue.UtcSampleTime, Double.NaN, originalValue.TextValue, originalValue.Quality, null);
return(true);
}
