====

[[sec:publishing-custom-components]]
== Creating and publishing custom components

In the <<sec:adding-variants-to-existing-components, previous example>>, we have demonstrated how to extend or modify an existing component, like the components provided by the Java plugins.
But Gradle also allows you to build a custom component (not a Java Library, not a Java Platform, not something supported natively by Gradle).

  TF_DataType dtype = TFE_TensorHandleDataType(components[0].get());
  // Verify that the TensorHandle's shape and dtype match all of the component
  // shapes and dtypes.
  for (TensorHandlePtr& component : components) {
    TFE_TensorHandleGetStatus(component.get(), status);
    if (!status->status.ok()) {
      return nullptr;
    }
    if (TFE_TensorHandleDataType(component.get()) != dtype) {
      TF_SetStatus(status, TF_INTERNAL,

 * in the project.  Some methods - such as {@link #registerFeature(String, Action)} -
 * are not applicable in this manner and will throw exceptions if used when multiple
 * {@link org.gradle.jvm.component.internal.JvmSoftwareComponentInternal JvmSoftwareComponentInternal}
 * components are present.
 *

        if (components.length == 0) {
            return path;
        }
        if (path.components.length == 0) {
            return this;
        }

        String[] descendantComponents = new String[components.length + path.components.length];
        arraycopy(components, 0, descendantComponents, 0, components.length);
        arraycopy(path.components, 0, descendantComponents, components.length, path.components.length);

                void mutateMyComponent(@Path("components.myComponent") $componentType component) {
                    component.data = "my component"
                }
                @Mutate
                void mutateMyComponentSource(@Path("components.myComponent.sources.myComponentSource") $sourceType componentSourceSet) {
                    componentSourceSet.data = "my component sources"
                }
                @Mutate

import org.gradle.internal.component.model.ComponentGraphSpecificResolveState
import org.gradle.internal.component.model.ComponentIdGenerator
import org.gradle.internal.component.model.ComponentOverrideMetadata
import org.gradle.internal.component.model.DependencyMetadata
import org.gradle.internal.component.model.ExcludeMetadata
import org.gradle.internal.component.model.GraphVariantSelector

            }

            T coordinates = componentCoordinates.get(component);
            if (!coordinatesSeen.add(coordinates)) {
                throw new InvalidUserDataException("Multiple child components may not share the same coordinates: " + coordinates);
            }

// end::guice-rule[]

// tag::guice-dependencies[]
dependencies {
    components {
        withModule<GuiceRule>("com.google.inject:guice")
    }
    implementation("com.google.inject:guice:4.2.2") {
        capabilities { requireCapability("com.google.inject:guice-no_aop") }
    }
}
// end::guice-dependencies[]


// tag::ivy-component-metadata-rule[]
@CacheableRule

        other 'org.test:projectA:1.0'

        // Component metadata rule that applies only to the 'sub' project
        components {
            withModule('org.test:projectA', AddDependencyRule)
        }
    }
    task res {
        def conf = configurations.conf
        def other = configurations.other
        doLast {
            // If we resolve twice the modified component metadata for 'projectA' must not be cached in-memory

        variant.nodeId >> componentId

        def component = Stub(DependencyGraphComponent)
        _ * component.resultId >> componentId
        _ * component.selectionReason >> root()
        _ * component.resolveState >> componentState
        _ * component.selectedVariants >> [variant]

        def node = Stub(RootGraphNode)
        _ * node.owner >> component