RenderProps 3.0.0

RenderProps encapsulates passing arguments from a node visitor to a node renderer. Without hardcoding arguments into an API method calls.

RenderProps is the state collection for Props that are set by a node visitor and retrieved by a node renderer.

public class Prop<T> {

    @NonNull
    public static <T> Prop<T> of(@NonNull String name) {
        return new Prop<>(name);
    }

    /* ... */
}

For example CorePlugin defines a Heading level prop (inside CoreProps class):

public static final Prop<Integer> HEADING_LEVEL = Prop.of("heading-level");

Then CorePlugin registers a Heading node visitor and applies heading value:

@Override
public void configureVisitor(@NonNull MarkwonVisitor.Builder builder) {
    builder.on(Heading.class, new MarkwonVisitor.NodeVisitor<Heading>() {
        @Override
        public void visit(@NonNull MarkwonVisitor visitor, @NonNull Heading heading) {
            
            /* Heading node handling logic */

            // set heading level
            CoreProps.HEADING_LEVEL.set(visitor.renderProps(), heading.getLevel());
            
            // a helper method to apply span(s) for a node 
            // (internally obtains a SpanFactory for Heading or silently ignores
            // this call if no factory for a Heading is registered)
            visitor.setSpansForNodeOptional(heading, start);

            /* Heading node handling logic */
        }
    });
}

And finally HeadingSpanFactory (which is also registered by CorePlugin):

public class HeadingSpanFactory implements SpanFactory {
    @Nullable
    @Override
    public Object getSpans(@NonNull MarkwonConfiguration configuration, @NonNull RenderProps props) {
        return new HeadingSpan(
                configuration.theme(),
                CoreProps.HEADING_LEVEL.require(props)
        );
    }
}

Prop<T> has these methods:

@Nullable T get(RenderProps) - returns value stored in RenderProps or null if none is present
@NonNull T get(RenderProps, @NonNull T defValue) - returns value stored in RenderProps or default value (this method always return non-null value)
@NonNull T require(RenderProps) - returns value stored in RenderProps or throws an exception if none is present
void set(RenderProps, @Nullable T value) - updates value stored in RenderProps, passing null as value is the same as calling clear
void clear(RenderProps) - clears value stored in RenderProps

# RenderProps 3.0.0

RenderProps 3.0.0