Components can't use interactive mode without tty

- Adding a concept of no-tty which in this commit simply
  tracks DumbTerminal as jline creates that if there nothing
  better.
- For components without tty don't go to interaction loop.
- For new sample show that we can at least manually handle
  required option with a flow while command option is not
  required.
- Fixes #444

spring-shell-core/src/main/java/org/springframework/shell/command/CommandExecution.java

@@ -210,6 +210,10 @@ public interface CommandExecution {
 			this.parserExceptions = parserExceptions;
 		}
 
+		public static CommandParserExceptionsException of(String message, List<CommandParserException> parserExceptions) {
+			return new CommandParserExceptionsException(message, parserExceptions);
+		}
+
 		public List<CommandParserException> getParserExceptions() {
 			return parserExceptions;
 		}

spring-shell-core/src/main/java/org/springframework/shell/component/ConfirmationInput.java

@@ -24,6 +24,8 @@ import org.jline.keymap.BindingReader;
 import org.jline.keymap.KeyMap;
 import org.jline.terminal.Terminal;
 import org.jline.utils.AttributedString;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import org.springframework.shell.component.ConfirmationInput.ConfirmationInputContext;
 import org.springframework.shell.component.context.ComponentContext;
@@ -39,6 +41,7 @@ import org.springframework.util.StringUtils;
  */
 public class ConfirmationInput extends AbstractTextComponent<Boolean, ConfirmationInputContext> {
 
+	private final static Logger log = LoggerFactory.getLogger(ConfirmationInput.class);
 	private final boolean defaultValue;
 	private ConfirmationInputContext currentContext;
 
@@ -78,6 +81,10 @@ public class ConfirmationInput extends AbstractTextComponent<Boolean, Confirmati
 	@Override
 	protected boolean read(BindingReader bindingReader, KeyMap<String> keyMap, ConfirmationInputContext context) {
 		String operation = bindingReader.readBinding(keyMap);
+		log.debug("Binding read result {}", operation);
+		if (operation == null) {
+			return true;
+		}
 		String input;
 		switch (operation) {
 			case OPERATION_CHAR:

spring-shell-core/src/main/java/org/springframework/shell/component/MultiItemSelector.java

@@ -70,7 +70,10 @@ public class MultiItemSelector<T, I extends Nameable & Matchable & Enableable &
 	@Override
 	protected MultiItemSelectorContext<T, I> runInternal(MultiItemSelectorContext<T, I> context) {
 		super.runInternal(context);
-		loop(context);
+		// if there's no tty don't try to loop as it would then cause user interaction
+		if (hasTty()) {
+			loop(context);
+		}
 		return context;
 	}
 

spring-shell-core/src/main/java/org/springframework/shell/component/PathInput.java

@@ -27,6 +27,8 @@ import org.jline.keymap.BindingReader;
 import org.jline.keymap.KeyMap;
 import org.jline.terminal.Terminal;
 import org.jline.utils.AttributedString;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import org.springframework.shell.component.PathInput.PathInputContext;
 import org.springframework.shell.component.context.ComponentContext;
@@ -42,6 +44,7 @@ import org.springframework.util.StringUtils;;
  */
 public class PathInput extends AbstractTextComponent<Path, PathInputContext> {
 
+	private final static Logger log = LoggerFactory.getLogger(PathInput.class);
 	private PathInputContext currentContext;
 	private Function<String, Path> pathProvider = (path) -> Paths.get(path);
 
@@ -75,6 +78,10 @@ public class PathInput extends AbstractTextComponent<Path, PathInputContext> {
 	@Override
 	protected boolean read(BindingReader bindingReader, KeyMap<String> keyMap, PathInputContext context) {
 		String operation = bindingReader.readBinding(keyMap);
+		log.debug("Binding read result {}", operation);
+		if (operation == null) {
+			return true;
+		}
 		String input;
 		switch (operation) {
 			case OPERATION_CHAR:

spring-shell-core/src/main/java/org/springframework/shell/component/SingleItemSelector.java

@@ -70,7 +70,10 @@ public class SingleItemSelector<T, I extends Nameable & Matchable & Enableable &
 	@Override
 	protected SingleItemSelectorContext<T, I> runInternal(SingleItemSelectorContext<T, I> context) {
 		super.runInternal(context);
-		loop(context);
+		// if there's no tty don't try to loop as it would then cause user interaction
+		if (hasTty()) {
+			loop(context);
+		}
 		return context;
 	}
 

spring-shell-core/src/main/java/org/springframework/shell/component/StringInput.java

@@ -24,6 +24,8 @@ import org.jline.keymap.BindingReader;
 import org.jline.keymap.KeyMap;
 import org.jline.terminal.Terminal;
 import org.jline.utils.AttributedString;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import org.springframework.shell.component.StringInput.StringInputContext;
 import org.springframework.shell.component.context.ComponentContext;
@@ -38,6 +40,7 @@ import org.springframework.util.StringUtils;
  */
 public class StringInput extends AbstractTextComponent<String, StringInputContext> {
 
+	private final static Logger log = LoggerFactory.getLogger(StringInput.class);
 	private final String defaultValue;
 	private StringInputContext currentContext;
 	private Character maskCharacter;
@@ -83,6 +86,10 @@ public class StringInput extends AbstractTextComponent<String, StringInputContex
 	@Override
 	protected boolean read(BindingReader bindingReader, KeyMap<String> keyMap, StringInputContext context) {
 		String operation = bindingReader.readBinding(keyMap);
+		log.debug("Binding read result {}", operation);
+		if (operation == null) {
+			return true;
+		}
 		String input;
 		switch (operation) {
 			case OPERATION_CHAR:

spring-shell-core/src/main/java/org/springframework/shell/component/context/ComponentContext.java

@@ -56,6 +56,14 @@ public interface ComponentContext<C extends ComponentContext<C>> {
 	 */
 	<T> T get(Object key, Class<T> type);
 
+	/**
+	 * Check if a context contains a key.
+	 *
+	 * @param key the key
+	 * @return true if context contains key
+	 */
+	boolean containsKey(Object key);
+
 	/**
 	 * Put an entry into a context.
 	 *

spring-shell-core/src/main/java/org/springframework/shell/component/support/AbstractComponent.java

@@ -33,6 +33,7 @@ import org.jline.keymap.KeyMap;
 import org.jline.terminal.Attributes;
 import org.jline.terminal.Size;
 import org.jline.terminal.Terminal;
+import org.jline.terminal.impl.DumbTerminal;
 import org.jline.utils.AttributedString;
 import org.jline.utils.Display;
 import org.jline.utils.InfoCmp.Capability;
@@ -153,7 +154,8 @@ public abstract class AbstractComponent<T extends ComponentContext<T>> implement
 		context = runPreRunHandlers(getThisContext(context));
 		T run = runInternal(getThisContext(context));
 		context = runPostRunHandlers(getThisContext(context));
-		if (printResults) {
+		// if there's no tty don't try to print results as it'd be pointless
+		if (printResults && hasTty()) {
 			printResults(context);
 		}
 		return run;
@@ -186,6 +188,22 @@ public abstract class AbstractComponent<T extends ComponentContext<T>> implement
 		this.templateLocation = templateLocation;
 	}
 
+	/**
+	 * Checks if this component has an existing {@code tty}.
+	 *
+	 * @return true if component has tty
+	 */
+	protected boolean hasTty() {
+		boolean hasTty = true;
+		if (this.terminal instanceof DumbTerminal) {
+			if (this.terminal.getSize().getRows() == 0) {
+				hasTty = false;
+			}
+		}
+		log.debug("Terminal is {} with size {}, marking hasTty as {}", this.terminal, this.terminal.getSize(), hasTty);
+		return hasTty;
+	}
+
 	/**
 	 * Render a given template with attributes.
 	 *

spring-shell-core/src/main/java/org/springframework/shell/component/support/AbstractSelectorComponent.java

@@ -26,6 +26,8 @@ import org.jline.keymap.BindingReader;
 import org.jline.keymap.KeyMap;
 import org.jline.terminal.Terminal;
 import org.jline.utils.InfoCmp.Capability;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import org.springframework.shell.component.context.BaseComponentContext;
 import org.springframework.shell.component.context.ComponentContext;
@@ -46,6 +48,7 @@ import static org.jline.keymap.KeyMap.key;
 public abstract class AbstractSelectorComponent<T, C extends SelectorComponentContext<T, I, C>, I extends Nameable & Matchable & Enableable & Itemable<T>>
 		extends AbstractComponent<C> {
 
+	private final static Logger log = LoggerFactory.getLogger(AbstractSelectorComponent.class);
 	protected final String name;
 	private final List<I> items;
 	private Comparator<I> comparator = (o1, o2) -> 0;
@@ -155,6 +158,10 @@ public abstract class AbstractSelectorComponent<T, C extends SelectorComponentCo
 		ItemStateViewProjection buildItemStateView = buildItemStateView(start.get(), thisContext);
 		List<ItemState<I>> itemStateView = buildItemStateView.items;
 		String operation = bindingReader.readBinding(keyMap);
+		log.debug("Binding read result {}", operation);
+		if (operation == null) {
+			return true;
+		}
 		String input;
 		switch (operation) {
 			case OPERATION_SELECT:

spring-shell-core/src/main/java/org/springframework/shell/component/support/AbstractTextComponent.java

@@ -66,7 +66,10 @@ public abstract class AbstractTextComponent<T, C extends TextComponentContext<T,
 
 	@Override
 	protected C runInternal(C context) {
-		loop(context);
+		// if there's no tty don't try to loop as it would then cause user interaction
+		if (hasTty()) {
+			loop(context);
+		}
 		return context;
 	}
 

spring-shell-core/src/test/java/org/springframework/shell/component/AbstractShellTests.java

@@ -25,6 +25,7 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.LinkedBlockingQueue;
 
 import org.jline.keymap.KeyMap;
+import org.jline.terminal.Size;
 import org.jline.terminal.Terminal;
 import org.jline.terminal.impl.DumbTerminal;
 import org.jline.utils.AttributedString;
@@ -79,6 +80,7 @@ public abstract class AbstractShellTests {
 
         pipedInputStream.connect(pipedOutputStream);
 		terminal = new DumbTerminal("terminal", "ansi", pipedInputStream, consoleOut, StandardCharsets.UTF_8);
+        terminal.setSize(new Size(1, 1));
 
         executorService.execute(() -> {
             try {

spring-shell-core/src/test/java/org/springframework/shell/component/ConfirmationInputTests.java

@@ -15,13 +15,17 @@
  */
 package org.springframework.shell.component;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 
+import org.jline.terminal.impl.DumbTerminal;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -55,6 +59,33 @@ public class ConfirmationInputTests extends AbstractShellTests {
 		service = null;
 	}
 
+	@Test
+	void testNoTty() throws Exception {
+		ByteArrayInputStream in = new ByteArrayInputStream(new byte[0]);
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		DumbTerminal dumbTerminal = new DumbTerminal("terminal", "ansi", in, out, StandardCharsets.UTF_8);
+
+		ComponentContext<?> empty = ComponentContext.empty();
+		ConfirmationInput component1 = new ConfirmationInput(dumbTerminal, "component1");
+		component1.setResourceLoader(new DefaultResourceLoader());
+		component1.setTemplateExecutor(getTemplateExecutor());
+
+		service.execute(() -> {
+			ConfirmationInputContext run1Context = component1.run(empty);
+			result1.set(run1Context);
+			latch1.countDown();
+		});
+
+		TestBuffer testBuffer = new TestBuffer().cr();
+		write(testBuffer.getBytes());
+
+		latch1.await(2, TimeUnit.SECONDS);
+		ConfirmationInputContext run1Context = result1.get();
+
+		assertThat(run1Context).isNotNull();
+		assertThat(run1Context.getResultValue()).isNull();
+	}
+
 	@Test
 	public void testResultUserInputEnterDefaultYes() throws InterruptedException, IOException {
 		ComponentContext<?> empty = ComponentContext.empty();

spring-shell-core/src/test/java/org/springframework/shell/component/MultiItemSelectorTests.java

@@ -15,6 +15,9 @@
  */
 package org.springframework.shell.component;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.nio.charset.StandardCharsets;
 import java.time.Duration;
 import java.util.Arrays;
 import java.util.List;
@@ -25,6 +28,8 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Stream;
 
+import org.jline.terminal.Terminal;
+import org.jline.terminal.impl.DumbTerminal;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -75,6 +80,19 @@ public class MultiItemSelectorTests extends AbstractShellTests {
 		service = null;
 	}
 
+	@Test
+	void testNoTty() throws Exception {
+		ByteArrayInputStream in = new ByteArrayInputStream(new byte[0]);
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		DumbTerminal dumbTerminal = new DumbTerminal("terminal", "ansi", in, out, StandardCharsets.UTF_8);
+
+		scheduleSelect(dumbTerminal);
+		awaitLatch();
+
+		List<SelectorItem<SimplePojo>> selected = result.get();
+		assertThat(selected).isNull();
+	}
+
 	@Test
 	public void testItemsShown() {
 		scheduleSelect();
@@ -192,12 +210,21 @@ public class MultiItemSelectorTests extends AbstractShellTests {
 				SELECTOR_ITEM_4));
 	}
 
+	private void scheduleSelect(Terminal terminal) {
+		scheduleSelect(Arrays.asList(SELECTOR_ITEM_1, SELECTOR_ITEM_2, SELECTOR_ITEM_3, SELECTOR_ITEM_4), null,
+				terminal);
+	}
+
 	private void scheduleSelect(List<SelectorItem<SimplePojo>> items) {
 		scheduleSelect(items, null);
 	}
 
 	private void scheduleSelect(List<SelectorItem<SimplePojo>> items, Integer maxItems) {
-		MultiItemSelector<SimplePojo, SelectorItem<SimplePojo>> selector = new MultiItemSelector<>(getTerminal(),
+		scheduleSelect(items, maxItems, getTerminal());
+	}
+
+	private void scheduleSelect(List<SelectorItem<SimplePojo>> items, Integer maxItems, Terminal terminal) {
+		MultiItemSelector<SimplePojo, SelectorItem<SimplePojo>> selector = new MultiItemSelector<>(terminal,
 				items, "testSimple", null);
 		selector.setResourceLoader(new DefaultResourceLoader());
 		selector.setTemplateExecutor(getTemplateExecutor());

spring-shell-core/src/test/java/org/springframework/shell/component/PathInputTests.java

@@ -15,7 +15,10 @@
  */
 package org.springframework.shell.component;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.FileSystem;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -27,6 +30,7 @@ import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Function;
 
 import com.google.common.jimfs.Jimfs;
+import org.jline.terminal.impl.DumbTerminal;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -69,6 +73,36 @@ public class PathInputTests extends AbstractShellTests {
 		pathProvider = null;
 	}
 
+	@Test
+	void testNoTty() throws Exception {
+		ByteArrayInputStream in = new ByteArrayInputStream(new byte[0]);
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		DumbTerminal dumbTerminal = new DumbTerminal("terminal", "ansi", in, out, StandardCharsets.UTF_8);
+
+		Path path = fileSystem.getPath("tmp");
+		Files.createDirectories(path);
+		ComponentContext<?> empty = ComponentContext.empty();
+		PathInput component1 = new PathInput(dumbTerminal, "component1");
+		component1.setPathProvider(pathProvider);
+		component1.setResourceLoader(new DefaultResourceLoader());
+		component1.setTemplateExecutor(getTemplateExecutor());
+
+		service.execute(() -> {
+			PathInputContext run1Context = component1.run(empty);
+			result1.set(run1Context);
+			latch1.countDown();
+		});
+
+		TestBuffer testBuffer = new TestBuffer().append("tmp").cr();
+		write(testBuffer.getBytes());
+
+		latch1.await(2, TimeUnit.SECONDS);
+		PathInputContext run1Context = result1.get();
+
+		assertThat(run1Context).isNotNull();
+		assertThat(run1Context.getResultValue()).isNull();
+	}
+
 	@Test
 	public void testResultUserInput() throws InterruptedException, IOException {
 		Path path = fileSystem.getPath("tmp");

spring-shell-core/src/test/java/org/springframework/shell/component/SingleItemSelectorTests.java

@@ -15,6 +15,9 @@
  */
 package org.springframework.shell.component;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.nio.charset.StandardCharsets;
 import java.time.Duration;
 import java.util.Arrays;
 import java.util.List;
@@ -25,6 +28,8 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 
+import org.jline.terminal.Terminal;
+import org.jline.terminal.impl.DumbTerminal;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -92,6 +97,19 @@ public class SingleItemSelectorTests extends AbstractShellTests {
 						"simplePojo3", "simplePojo4", "simplePojo5", "simplePojo6"));
 	}
 
+	@Test
+	void testNoTty() throws Exception {
+		ByteArrayInputStream in = new ByteArrayInputStream(new byte[0]);
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		DumbTerminal dumbTerminal = new DumbTerminal("terminal", "ansi", in, out, StandardCharsets.UTF_8);
+
+		scheduleSelect(dumbTerminal);
+		awaitLatch();
+
+		Optional<SelectorItem<SimplePojo>> selected = result.get();
+		assertThat(selected).isEmpty();
+	}
+
 	@Test
 	public void testSelectFirst() throws InterruptedException {
 		scheduleSelect();
@@ -156,9 +174,13 @@ public class SingleItemSelectorTests extends AbstractShellTests {
 		assertThat(selected).isNotEmpty();
 	}
 
+	private void scheduleSelect(Terminal terminal) {
+		scheduleSelect(Arrays.asList(SELECTOR_ITEM_1, SELECTOR_ITEM_2, SELECTOR_ITEM_3, SELECTOR_ITEM_4), null,
+				terminal);
+	}
+
 	private void scheduleSelect() {
-		scheduleSelect(Arrays.asList(SELECTOR_ITEM_1, SELECTOR_ITEM_2, SELECTOR_ITEM_3,
-				SELECTOR_ITEM_4));
+		scheduleSelect(Arrays.asList(SELECTOR_ITEM_1, SELECTOR_ITEM_2, SELECTOR_ITEM_3, SELECTOR_ITEM_4));
 	}
 
 	private void scheduleSelect(List<SelectorItem<SimplePojo>> items) {
@@ -166,7 +188,11 @@ public class SingleItemSelectorTests extends AbstractShellTests {
 	}
 
 	private void scheduleSelect(List<SelectorItem<SimplePojo>> items, Integer maxItems) {
-		SingleItemSelector<SimplePojo, SelectorItem<SimplePojo>> selector = new SingleItemSelector<>(getTerminal(),
+		scheduleSelect(items, maxItems, getTerminal());
+	}
+
+	private void scheduleSelect(List<SelectorItem<SimplePojo>> items, Integer maxItems, Terminal terminal) {
+		SingleItemSelector<SimplePojo, SelectorItem<SimplePojo>> selector = new SingleItemSelector<>(terminal,
 				items, "testSimple", null);
 		selector.setResourceLoader(new DefaultResourceLoader());
 		selector.setTemplateExecutor(getTemplateExecutor());

spring-shell-core/src/test/java/org/springframework/shell/component/StringInputTests.java

@@ -15,12 +15,16 @@
  */
 package org.springframework.shell.component;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.nio.charset.StandardCharsets;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 
+import org.jline.terminal.impl.DumbTerminal;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -60,6 +64,34 @@ public class StringInputTests extends AbstractShellTests {
 		service = null;
 	}
 
+	@Test
+	void testNoTty() throws Exception {
+		ByteArrayInputStream in = new ByteArrayInputStream(new byte[0]);
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		DumbTerminal dumbTerminal = new DumbTerminal("terminal", "ansi", in, out, StandardCharsets.UTF_8);
+
+		ComponentContext<?> empty = ComponentContext.empty();
+		StringInput component1 = new StringInput(dumbTerminal, "component1", "component1ResultValue");
+		component1.setPrintResults(true);
+		component1.setResourceLoader(new DefaultResourceLoader());
+		component1.setTemplateExecutor(getTemplateExecutor());
+
+		service.execute(() -> {
+			StringInputContext run1Context = component1.run(empty);
+			result1.set(run1Context);
+			latch1.countDown();
+		});
+
+		TestBuffer testBuffer = new TestBuffer().cr();
+		write(testBuffer.getBytes());
+
+		latch1.await(2, TimeUnit.SECONDS);
+		StringInputContext run1Context = result1.get();
+
+		assertThat(run1Context).isNotNull();
+		assertThat(run1Context.getResultValue()).isNull();
+	}
+
 	@Test
 	public void testResultBasic() throws InterruptedException {
 		ComponentContext<?> empty = ComponentContext.empty();

spring-shell-core/src/test/java/org/springframework/shell/component/flow/AbstractShellTests.java

@@ -25,6 +25,7 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.LinkedBlockingQueue;
 
 import org.jline.keymap.KeyMap;
+import org.jline.terminal.Size;
 import org.jline.terminal.Terminal;
 import org.jline.terminal.impl.DumbTerminal;
 import org.jline.utils.AttributedString;
@@ -79,6 +80,7 @@ public abstract class AbstractShellTests {
 
         pipedInputStream.connect(pipedOutputStream);
 		terminal = new DumbTerminal("terminal", "ansi", pipedInputStream, consoleOut, StandardCharsets.UTF_8);
+        terminal.setSize(new Size(1, 1));
 
         executorService.execute(() -> {
             try {

spring-shell-samples/src/main/java/org/springframework/shell/samples/standard/ComponentFlowCommands.java

@@ -23,15 +23,23 @@ import java.util.Map;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
+import org.jline.terminal.impl.DumbTerminal;
+
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.shell.command.CommandExecution.CommandParserExceptionsException;
+import org.springframework.shell.command.CommandParser;
+import org.springframework.shell.command.CommandParser.CommandParserException;
+import org.springframework.shell.command.CommandRegistration;
 import org.springframework.shell.component.flow.ComponentFlow;
+import org.springframework.shell.component.flow.ComponentFlow.ComponentFlowResult;
 import org.springframework.shell.component.flow.ResultMode;
 import org.springframework.shell.component.flow.SelectItem;
-import org.springframework.shell.component.flow.ComponentFlow.ComponentFlowResult;
 import org.springframework.shell.standard.AbstractShellComponent;
 import org.springframework.shell.standard.ShellComponent;
 import org.springframework.shell.standard.ShellMethod;
 import org.springframework.shell.standard.ShellOption;
+import org.springframework.util.StringUtils;
 
 @ShellComponent
 public class ComponentFlowCommands extends AbstractShellComponent {
@@ -133,6 +141,117 @@ public class ComponentFlowCommands extends AbstractShellComponent {
 		return buf.toString();
 	}
 
+	@Bean
+	public CommandRegistration showcaseRegistration() {
+		return CommandRegistration.builder()
+			.command("flow", "showcase3")
+			.description("Showcase")
+			.withOption()
+				.longNames("field1")
+				.and()
+			.withOption()
+				.longNames("field2")
+				.and()
+			.withOption()
+				.longNames("confirmation1")
+				.type(Boolean.class)
+				.and()
+			.withOption()
+				.longNames("path1")
+				.and()
+			.withOption()
+				.longNames("single1")
+				.and()
+			.withOption()
+				.longNames("multi1")
+				.and()
+			.withTarget()
+				.consumer(ctx -> {
+
+					String field1 = ctx.getOptionValue("field1");
+					String field2 = ctx.getOptionValue("field2");
+					Boolean confirmation1 = ctx.getOptionValue("confirmation1");
+					String path1 = ctx.getOptionValue("path1");
+					String single1 = ctx.getOptionValue("single1");
+					String asdf = ctx.getOptionValue("multi1");
+					List<String> multi1 = new ArrayList<>();
+					if (StringUtils.hasText(asdf)) {
+						multi1.add(asdf);
+					}
+
+					Map<String, String> single1SelectItems = new HashMap<>();
+					single1SelectItems.put("key1", "value1");
+					single1SelectItems.put("key2", "value2");
+					List<SelectItem> multi1SelectItems = Arrays.asList(SelectItem.of("key1", "value1"),
+							SelectItem.of("key2", "value2"), SelectItem.of("key3", "value3"));
+					ComponentFlow flow = componentFlowBuilder.clone().reset()
+							.withStringInput("field1")
+								.name("Field1")
+								.defaultValue("defaultField1Value")
+								.resultValue(field1)
+								.resultMode(ResultMode.ACCEPT)
+								.and()
+							.withStringInput("field2")
+								.name("Field2")
+								.resultValue(field2)
+								.resultMode(ResultMode.ACCEPT)
+								.and()
+							.withConfirmationInput("confirmation1")
+								.name("Confirmation1")
+								.resultValue(confirmation1)
+								.resultMode(ResultMode.ACCEPT)
+								.and()
+							.withPathInput("path1")
+								.name("Path1")
+								.resultValue(path1)
+								.resultMode(ResultMode.ACCEPT)
+								.and()
+							.withSingleItemSelector("single1")
+								.name("Single1")
+								.selectItems(single1SelectItems)
+								.resultValue(single1)
+								.resultMode(ResultMode.ACCEPT)
+								.and()
+							.withMultiItemSelector("multi1")
+								.name("Multi1")
+								.selectItems(multi1SelectItems)
+								.resultValues(multi1)
+								.resultMode(ResultMode.ACCEPT)
+								.and()
+							.build();
+					ComponentFlowResult result = flow.run();
+
+					boolean hasTty = !((ctx.getTerminal() instanceof DumbTerminal) && ctx.getTerminal().getSize().getRows() == 0);
+					if (hasTty) {
+						StringBuilder buf = new StringBuilder();
+						result.getContext().stream().forEach(e -> {
+							buf.append(e.getKey());
+							buf.append(" = ");
+							buf.append(e.getValue());
+							buf.append("\n");
+						});
+						ctx.getTerminal().writer().print(buf.toString());
+						ctx.getTerminal().writer().flush();
+					}
+					else {
+						List<CommandParser.CommandParserException> errors = new ArrayList<>();
+						result.getContext().stream().forEach(e -> {
+							if (e.getValue() == null) {
+								errors.add(CommandParserException.of(String.format("Missing option, longnames='%s'", e.getKey())));
+							}
+						});
+						if (!result.getContext().containsKey("single1")) {
+							errors.add(CommandParserException.of("Missing option, longnames='single'"));
+						}
+						if (!errors.isEmpty()) {
+							throw CommandParserExceptionsException.of("Missing options", errors);
+						}
+					}
+				})
+				.and()
+			.build();
+	}
+
 	@ShellMethod(key = "flow conditional", value = "Second component based on first", group = "Flow")
 	public void conditional() {
 		Map<String, String> single1SelectItems = new HashMap<>();