Class RuleSource
- java.lang.Object
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- org.gradle.model.RuleSource
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@Incubating public class RuleSource extends java.lang.Object
A marker type for a class that is a collection of rules.A rule source is not used like a regular Java object. It is a stateless container of methods and possibly constants.
Please consult the “Rule based model configuration” chapter of the Gradle User Manual for general information about “rules”.
Rule methods
Each method that is annotated with one of the following is considered a rule:
Each annotation specifies the type of the rule, which affects when it will be executed.
The following constraints apply to all rule methods:
- A method may only be annotated by at most one of the above annotations.
- A rule method may be
staticor not; it makes no difference. - A rule method cannot be generic (i.e. cannot have type parameters).
- With the exception of
Modelmethods, all methods must have at least one parameter. - With the exception of
Modelmethods, all methods must have avoidreturn type.
See
Modelfor information on the significance of the return type of aModelmethod.Subjects and inputs
Method rules declare the subject and any inputs as parameters to the method. With the exception of
Modelmethods, the subject of the rule is the, required, first parameter and all subsequent parameters are inputs. For a non-voidModelmethod, the subject (i.e. model element being created) is the return object. For a voidModelmethod, the subject is the first method parameter.The
Pathannotation can be placed on any parameter (except the subject ofModelrules) to indicate the model element to bind to. If there is noPathannotation, a “by-type” binding will be attempted. The binding scope is determined by how the rule source is applied.General class constraints
Along with the constraints on individual rule methods by their associated annotation, the following are general constraints of rule source implementations:
- Constructors are not allowed.
- Inheritance hierarchies are not allowed (i.e. all rules sources must directly extend
RuleSource). - Instance variables are not allowed.
- Non-final static variables are not allowed (i.e. constants are allowed).
- Methods cannot be overloaded.
- Implementations cannot be generic (i.e. cannot use type parameters).
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Constructor Summary
Constructors Constructor Description RuleSource()
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