ActionAttribute Class

Assembly: CodeEffects.Rule.Common.dll
Namespace: CodeEffects.Rule.Common.Attributes

Summary

IMPORTANT Generic methods with generic params cannot be used in Source XML as in-rule methods or rule actions. Use plain .Net class(es) if your source object declares generic methods.

If applied to a qualified public method of the source object, this attribute marks that method as a rule action available for use in execution-type rules. To qualify, the method must be public, static or instance, return System.Void and either be parameterless or have only parameters of the source object type or any value type supported by Code Effects.

This attribute can also be applied to a qualified method of any other public class declared in any assembly accessible to the code that evaluates the rule, making that method available as a rule action as well. In such cases, the source object must be decorated with the ExternalActionAttribute, which references the external method by its name and class type.

Syntax

[AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
public class ActionAttribute : System.Attribute,
	CodeEffects.Rule.Common.Attributes.IDescribableAttribute

Properties

Remarks

This attribute is optional. The Rule Editor uses any qualified method of the source object as a rule action, regardless of whether it is decorated with the ActionAttribute. The Rule Editor ignores any qualified methods that are decorated with the ExcludeFromEvaluationAttribute. If the ActionAttribute is applied to a non-qualified method, an exception is thrown. All non-qualified methods that are not decorated with the ActionAttribute are ignored.

Remember that action methods can accept your source object as a parameter. It is a useful feature for static action methods. When a rule author uses such an action in a rule, parameters of the source object type are not displayed — Rule Editor passes them automatically. In the Rule XML, the parameter of the source object type is represented as this.

The following example illustrates how the rule would appear in Rule Area when a user uses both actions from the code sample below:

If ID is greater than 10 then Rename the Thing (New Name) and Set New ID (20)

Note that the second method is displayed with only the int parameter. Your instance of the Thing type is passed to the method automatically at evaluation time; it is omitted by the editor in the Rule Area.

Example

using CodeEffects.Rule.Common.Attributes;

namespace TestLibrary
{
	[Source]
	public class Thing
	{
		public int ID {get; set; } = 0;
		public string Name { get; set; }

		[Action("Rename the Thing", "Gives a different name to the Thing")]
		public void Rename(string newName)
		{
			this.Name = newName;
		}

		[Action("Set New ID", "Sets a new ID of the Thing")]
		public static void SetID(Thing thing, int id)
		{
			thing.ID = id;
		}
	}
}