Package software.amazon.smithy.codegen.core.writer

Interface UseShapeWriterObserver<T extends CodegenWriter<T,?>>

Type Parameters:

T - Type of CodegenWriter being used.

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface UseShapeWriterObserver<T extends CodegenWriter<T,?>>

An observer invoked when a shape CodegenWriter is used.

The following example defines a UseShapeWriterObserver that writes a comment before a shape is written:

 public final class MyObserver implements UseShapeWriterObserver<MyWriter> {
     \@Override
     public void observe(Shape shape, Symbol symbol, SymbolProvider symbolProvider, MyWriter writer) {
         writer.write("/// Writing $L", shape.getId());
     }
 }
 

Method Summary

Modifier and Type	Method	Description
void	observe(Shape shape, Symbol symbol, SymbolProvider symbolProvider, T writer)	Invoked when a CodegenWriter writer is used via CodegenWriterDelegator.useShapeWriter(Shape, Consumer).

Method Detail

observe

void observe(Shape shape,
             Symbol symbol,
             SymbolProvider symbolProvider,
             T writer)

Invoked when a CodegenWriter writer is used via CodegenWriterDelegator.useShapeWriter(Shape, Consumer).

This is an extension point that allows code generators to perform any kind of preprocessing they need before code is written to a CodegenWriter for a given shape. For example, this could be used to add comments to the generated code to indicate that a file is auto-generated.

This method is invoked before the writerConsumer of CodegenWriterDelegator.useShapeWriter(software.amazon.smithy.model.shapes.Shape, java.util.function.Consumer<T>) is called. This method is invoked within a pushed CodegenWriter state, so any state modifications made to the CodegenWriter will not persist after the the writerConsumer has completed (e.g., calls to methods like CodeWriter.indent() are not persisted).

Parameters:

shape - Shape being used.

symbol - Symbol of the shape.

symbolProvider - SymbolProvider associated with the delegator.

writer - Writer being used for the shape.