Merge pull request #458 from NicolasMassart/321-add-support-for-IDefa…

…ultValueProvider

#321 add support for default value provider

src/main/java/picocli/CommandLine.java

@@ -409,6 +409,23 @@ public CommandLine setEndOfOptionsDelimiter(String delimiter) {
  return this;
  }
 
+ /** Sets a default value provider for the command and sub-commands
+ * <p>The specified setting will be registered with this {@code CommandLine} and the full hierarchy of its
+ * sub-commands and nested sub-subcommands <em>at the moment this method is called</em>. Sub-commands added
+ * later will have the default setting. To ensure a setting is applied to all
+ * sub-commands, call the setter last, after adding sub-commands.</p>
+ * @param newValue the default value provider to use
+ * @return this {@code CommandLine} object, to allow method chaining
+ * @since 3.6
+ */
+ public CommandLine setDefaultValueProvider(IDefaultValueProvider newValue) {
+ getCommandSpec().defaultValueProvider(newValue);
+ for (CommandLine command : getCommandSpec().subcommands().values()) {
+ command.setDefaultValueProvider(newValue);
+ }
+ return this;
+ }
+
  /** Returns whether the parser interprets the first positional parameter as "end of options" so the remaining
  * arguments are all treated as positional parameters. The default is {@code false}.
  * @return {@code true} if all values following the first positional parameter should be treated as positional parameters, {@code false} otherwise
@@ -2870,6 +2887,12 @@ private static class NoCompletionCandidates implements Iterable<String> {
  * @return the character to show in the options list to mark required options */
  char requiredOptionMarker() default ' ';
 
+ /** Class that can provide default values dynamically at runtime. An implementation may return default
+ * value obtained from a configuration file like a properties file or some other source.
+ * @return a Class that can provide default values dynamically at runtime
+ * @since 3.6 */
+ Class<? extends IDefaultValueProvider> defaultValueProvider() default NoDefaultProvider.class;
+
  /** Specify {@code true} to show default values in the description column of the options list (except for
  * boolean options). False by default.
  * <p>Note that picocli 3.2 allows {@linkplain Option#description() embedding default values} anywhere in the
@@ -3007,6 +3030,27 @@ private static class NoVersionProvider implements IVersionProvider {
  public String[] getVersion() throws Exception { throw new UnsupportedOperationException(); }
  }
 
+ /**
+ * Provides default value for a command. Commands may configure a provider with the
+ * {@link Command#defaultValueProvider()} annotation attribute.
+ * @since 3.6 */
+ public interface IDefaultValueProvider {
+
+ /** Returns the default value for an option or positional parameter or {@code null}.
+ * The returned value is converted to the type of the option/positional parameter
+ * via the same type converter used when populating this option/positional
+ * parameter from a command line argument.
+ * @param argSpec the option or positional parameter, never {@code null}
+ * @return the default value for the option or positional parameter, or {@code null} if
+ * this provider has no default value for the specified option or positional parameter
+ * @throws Exception an exception detailing what went wrong when obtaining default value
+ */
+ String defaultValue(ArgSpec argSpec) throws Exception;
+ }
+ private static class NoDefaultProvider implements IDefaultValueProvider {
+ public String defaultValue(ArgSpec argSpec) { throw new UnsupportedOperationException(); }
+ }
+
  /**
  * Factory for instantiating classes that are registered declaratively with annotation attributes, like
  * {@link Command#subcommands()}, {@link Option#converter()}, {@link Parameters#converter()} and {@link Command#versionProvider()}.
@@ -3049,6 +3093,9 @@ private static ITypeConverter<?>[] createConverter(IFactory factory, Class<? ext
  static IVersionProvider createVersionProvider(IFactory factory, Class<? extends IVersionProvider> cls) {
  return create(factory, cls);
  }
+ static IDefaultValueProvider createDefaultValueProvider(IFactory factory, Class<? extends IDefaultValueProvider> cls) {
+ return create(factory, cls);
+ }
  static Iterable<String> createCompletionCandidates(IFactory factory, Class<? extends Iterable<String>> cls) {
  return create(factory, cls);
  }
@@ -3330,6 +3377,7 @@ public static class CommandSpec {
  private Set<String> aliases = new LinkedHashSet<String>();
  private Boolean isHelpCommand;
  private IVersionProvider versionProvider;
+ private IDefaultValueProvider defaultValueProvider;
  private String[] version;
  private String toString;
 
@@ -3543,6 +3591,7 @@ public CommandSpec addMixin(String name, CommandSpec mixin) {
  initVersion(mixin.version());
  initHelpCommand(mixin.helpCommand());
  initVersionProvider(mixin.versionProvider());
+ initDefaultValueProvider(mixin.defaultValueProvider());
  usageMessage.initSynopsisHeading(mixin.usageMessage.synopsisHeading());
  usageMessage.initCommandListHeading(mixin.usageMessage.commandListHeading());
  usageMessage.initRequiredOptionMarker(mixin.usageMessage.requiredOptionMarker());
@@ -3674,6 +3723,17 @@ public CommandSpec aliases(String... aliases) {
  return this;
  }
 
+ /** Returns the default value provider for this command.
+ * @return the default value provider or {@code null}
+ * @since 3.6 */
+ public IDefaultValueProvider defaultValueProvider() { return defaultValueProvider; }
+
+ /** Sets default value provider for this command.
+ * @param defaultValueProvider the default value provider to use, or {@code null}.
+ * @return this CommandSpec for method chaining
+ * @since 3.6 */
+ public CommandSpec defaultValueProvider(IDefaultValueProvider defaultValueProvider) { this.defaultValueProvider = defaultValueProvider; return this; }
+
  /** Sets version information literals for this command, to print to the console when the user specifies an
  * {@linkplain OptionSpec#versionHelp() option} to request version help. Only used if no {@link #versionProvider() versionProvider} is set.
  * @return this CommandSpec for method chaining */
@@ -3724,7 +3784,10 @@ public CommandSpec mixinStandardHelpOptions(boolean newValue) {
  void initVersionProvider(Class<? extends IVersionProvider> value, IFactory factory) {
  if (initializable(versionProvider, value, NoVersionProvider.class)) { versionProvider = (DefaultFactory.createVersionProvider(factory, value)); }
  }
-
+ void initDefaultValueProvider(IDefaultValueProvider value) { if (defaultValueProvider == null) { defaultValueProvider = value; } }
+ void initDefaultValueProvider(Class<? extends IDefaultValueProvider> value, IFactory factory) {
+ if (initializable(defaultValueProvider, value, NoDefaultProvider.class)) { defaultValueProvider = (DefaultFactory.createDefaultValueProvider(factory, value)); }
+ }
  /** Returns the option with the specified short name, or {@code null} if no option with that name is defined for this command. */
  public OptionSpec findOption(char shortName) { return findOption(shortName, options()); }
  /** Returns the option with the specified name, or {@code null} if no option with that name is defined for this command.
@@ -5382,6 +5445,7 @@ private static boolean updateCommandAttributes(Command cmd, CommandSpec commandS
  commandSpec.initVersion(cmd.version());
  commandSpec.initHelpCommand(cmd.helpCommand());
  commandSpec.initVersionProvider(cmd.versionProvider(), factory);
+ commandSpec.initDefaultValueProvider(cmd.defaultValueProvider(), factory);
  UsageMessageSpec usageMessage = commandSpec.usageMessage();
  usageMessage.initSynopsisHeading(cmd.synopsisHeading());
  usageMessage.initCommandListHeading(cmd.commandListHeading());
@@ -6221,18 +6285,29 @@ private void parse(List<CommandLine> parsedCommands, Stack<String> argumentStack
 
  private void applyDefaultValues(List<ArgSpec> required) throws Exception {
  parseResult.isInitializingDefaultValues = true;
- for (OptionSpec option : commandSpec.options()) { applyDefault(option, required); }
- for (PositionalParamSpec positional : commandSpec.positionalParameters()) { applyDefault(positional, required); }
+ for (OptionSpec option : commandSpec.options()) { applyDefault(commandSpec.defaultValueProvider(), option, required); }
+ for (PositionalParamSpec positional : commandSpec.positionalParameters()) { applyDefault(commandSpec.defaultValueProvider(), positional, required); }
  parseResult.isInitializingDefaultValues = false;
  }
 
- private void applyDefault(ArgSpec arg, List<ArgSpec> required) throws Exception {
- if (arg.defaultValue() == null) { return; }
- if (tracer.isDebug()) {tracer.debug("Applying defaultValue (%s) to %s%n", arg.defaultValue(), arg);}
+ private void applyDefault(IDefaultValueProvider defaultValueProvider,
+ ArgSpec arg, List<ArgSpec> required) throws Exception {
+
+ boolean isDefaultOrInitialVaLuePresent = arg.defaultValue() != null || arg.initialValue() != null;
+
+ // Default value provider is only used if the argSpec doesn't already have a default
+ // value or an initial value
+ String defaultValue = defaultValueProvider != null && !isDefaultOrInitialVaLuePresent ?
+ defaultValueProvider.defaultValue(arg) : arg.defaultValue() ;
+
+ if (defaultValue == null) { return; }
+ if (tracer.isDebug()) {tracer.debug("Applying defaultValue (%s) to %s%n", defaultValue, arg);}
  Range arity = arg.arity().min(Math.max(1, arg.arity().min));
- applyOption(arg, LookBehind.SEPARATE, arity, stack(arg.defaultValue()), new HashSet<ArgSpec>(), arg.toString);
+
+ applyOption(arg, LookBehind.SEPARATE, arity, stack(defaultValue), new HashSet<ArgSpec>(), arg.toString);
  required.remove(arg);
  }
+
  private Stack<String> stack(String value) {Stack<String> result = new Stack<String>(); result.push(value); return result;}
 
  private void processArguments(List<CommandLine> parsedCommands,

src/test/java/picocli/CommandLineDefaultProviderTest.java

@@ -0,0 +1,110 @@
+package picocli;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import org.junit.Test;
+import picocli.CommandLine.Command;
+import picocli.CommandLine.IDefaultValueProvider;
+import picocli.CommandLine.Model.ArgSpec;
+import picocli.CommandLine.Option;
+import picocli.CommandLine.Parameters;
+
+public class CommandLineDefaultProviderTest {
+
+ static class TestDefaultProvider implements IDefaultValueProvider {
+ public String defaultValue(ArgSpec argSpec) {
+ return "Default provider string value";
+ }
+ }
+
+ @Command(defaultValueProvider = TestDefaultProvider.class)
+ static class App {
+ @Option(names = "-a")
+ private String optionStringFieldWithoutDefaultNorInitialValue;
+ @Option(names = "-b", defaultValue = "Annotated default value")
+ private String optionStringFieldWithAnnotatedDefault;
+ @Option(names = "-c")
+ private String optionStringFieldWithInitDefault = "Initial default value";
+
+ @Parameters(arity = "0..1")
+ private String paramStringFieldWithoutDefaultNorInitialValue;
+ @Parameters(arity = "0..1", defaultValue = "Annotated default value")
+ private String paramStringFieldWithAnnotatedDefault;
+ @Parameters(arity = "0..1")
+ private String paramStringFieldWithInitDefault = "Initial default value";
+
+ private String stringForSetterDefault;
+ @Option(names = "-d", defaultValue = "Annotated setter default value")
+ void setString(String val) { stringForSetterDefault = val; }
+ }
+
+ @Command(name = "sub")
+ static class Sub {
+ @Option(names = "-a")
+ private String optionStringFieldWithoutDefaultNorInitialValue;
+ @Option(names = "-b", defaultValue = "Annotated default value")
+ private String optionStringFieldWithAnnotatedDefault;
+ @Option(names = "-c")
+ private String optionStringFieldWithInitDefault = "Initial default value";
+
+ @Parameters(arity = "0..1")
+ private String paramStringFieldWithoutDefaultNorInitialValue;
+ @Parameters(arity = "0..1", defaultValue = "Annotated default value")
+ private String paramStringFieldWithAnnotatedDefault;
+ @Parameters(arity = "0..1")
+ private String paramStringFieldWithInitDefault = "Initial default value";
+
+ private String stringForSetterDefault;
+ @Option(names = "-d", defaultValue = "Annotated setter default value")
+ void setString(String val) { stringForSetterDefault = val; }
+ }
+
+
+ @Test
+ public void testCommandDefaultProviderByAnnotation() {
+ CommandLine cmd = new CommandLine(App.class);
+ cmd.parse();
+
+ App app = cmd.getCommand();
+ // if no default defined on the option, command default provider should be used
+ assertEquals("Default provider string value",app.optionStringFieldWithoutDefaultNorInitialValue);
+ assertEquals("Default provider string value",app.paramStringFieldWithoutDefaultNorInitialValue);
+ // if a default is defined on the option either by annotation or by initial value, it must
+ // override the default provider.
+ assertEquals("Annotated default value",app.optionStringFieldWithAnnotatedDefault);
+ assertEquals("Annotated default value",app.paramStringFieldWithAnnotatedDefault);
+
+ assertEquals("Initial default value",app.optionStringFieldWithInitDefault);
+ assertEquals("Initial default value",app.paramStringFieldWithInitDefault);
+
+ assertEquals("Annotated setter default value",app.stringForSetterDefault);
+ }
+
+ @Test
+ public void testDefaultProviderPropagatedToSubCommand() {
+ CommandLine cmd = new CommandLine(App.class);
+
+ cmd.addSubcommand("sub", new CommandLine(Sub.class));
+
+ CommandLine subCommandLine = cmd.getSubcommands().get("sub");
+ cmd.setDefaultValueProvider(new TestDefaultProvider());
+
+ assertNotNull(subCommandLine.getCommandSpec().defaultValueProvider());
+ assertEquals(TestDefaultProvider.class, subCommandLine.getCommandSpec().defaultValueProvider().getClass());
+ }
+
+ @Test
+ public void testCommandDefaultProviderSetting() {
+
+ CommandLine cmd = new CommandLine(App.class);
+ cmd.setDefaultValueProvider(new TestDefaultProvider());
+ cmd.parse();
+
+ App app = cmd.getCommand();
+ // if no default defined on the option, command default provider should be used
+ assertEquals("Default provider string value",app.optionStringFieldWithoutDefaultNorInitialValue);
+ }
+}