rabbitmq-trigger-binding.cs

public class RabbitMqTriggerBinding : ITriggerBinding
{
    private readonly ILogger _logger;

    public Type TriggerValueType => typeof(BasicDeliverEventArgs);

    public IReadOnlyDictionary<string, Type> BindingDataContract => new Dictionary<string, Type>();

    private readonly ParameterInfo _parameter;

    public RabbitMqTriggerBinding(ParameterInfo parameter, ILogger logger)
    {
        _parameter = parameter;
        _logger = logger;
    }

    public Task<ITriggerData> BindAsync(object value, ValueBindingContext context)
    {
        BasicDeliverEventArgs message = value as BasicDeliverEventArgs;

        IReadOnlyDictionary<string, object> bindingData = CreateBindingData(message);
        return Task.FromResult<ITriggerData>(new TriggerData(null, bindingData));
    }

    public Task<IListener> CreateListenerAsync(ListenerFactoryContext context)
    {
        var execuror = context.Executor;
        RabbitMqTriggerAttribute attr = _parameter.GetCustomAttribute<RabbitMqTriggerAttribute>();
        var listener = new RabbitMqTriggerListener(execuror, attr, _logger);

        return Task.FromResult<IListener>(listener);
    }

    public ParameterDescriptor ToParameterDescriptor()
    {
        return new TriggerParameterDescriptor
        {
            Name = "Parametr: RabbitMqTrigger",
            DisplayHints = new ParameterDisplayHints
            {
                Prompt = "RabbitMq Trigger",
                Description = "RabbitMq message trigger"
            }
        };
    }

    internal static IReadOnlyDictionary<string, object> CreateBindingData(BasicDeliverEventArgs value)
    {
        var bindingData = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);

        SafeAddValue(() => bindingData.Add(nameof(value.ConsumerTag), value.ConsumerTag));
        SafeAddValue(() => bindingData.Add(nameof(value.DeliveryTag), value.DeliveryTag));
        SafeAddValue(() => bindingData.Add(nameof(value.Redelivered), value.Redelivered));
        SafeAddValue(() => bindingData.Add(nameof(value.Exchange), value.Exchange));
        SafeAddValue(() => bindingData.Add(nameof(value.RoutingKey), value.RoutingKey));
        SafeAddValue(() => bindingData.Add(nameof(value.BasicProperties), value.BasicProperties));
        SafeAddValue(() => bindingData.Add(nameof(value.Body), value.Body));

        return bindingData;
    }

    private static void SafeAddValue(Action addValue)
    {
        try
        {
            addValue();
        }
        catch
        {
            // some message property getters can throw, based on the
            // state of the message
        }
    }
}