Migrate module input persistence to ModuleService

This makes the LoadInputsPreprocessor and SaveInputsPreprocessor much
simpler, since they can now simply lean on the ModuleService directly.

This also makes the DynamicCommand's internal saveInputs() method no
longer need to instantiate and run a SaveInputsPreprocessor, but
rather instead it can call that same service method in ModuleService.

Author: ctrueden

pom.xml

@@ -10,7 +10,7 @@
 	</parent>
 
 	<artifactId>scijava-common</artifactId>
-	<version>2.78.1-SNAPSHOT</version>
+	<version>2.79.0-SNAPSHOT</version>
 
 	<name>SciJava Common</name>
 	<description>SciJava Common is a shared library for SciJava software. It provides a plugin framework, with an extensible mechanism for service discovery, backed by its own annotation processor, so that plugins can be loaded dynamically. It is used by downstream projects in the SciJava ecosystem, such as ImageJ and SCIFIO.</description>

src/main/java/org/scijava/command/DynamicCommand.java

@@ -39,10 +39,8 @@
 import org.scijava.Contextual;
 import org.scijava.NullContextException;
 import org.scijava.module.DefaultMutableModule;
-import org.scijava.module.process.PreprocessorPlugin;
-import org.scijava.module.process.SaveInputsPreprocessor;
+import org.scijava.module.ModuleService;
 import org.scijava.plugin.Parameter;
-import org.scijava.plugin.PluginInfo;
 import org.scijava.plugin.PluginService;
 import org.scijava.util.ClassUtils;
 
@@ -67,6 +65,9 @@ public abstract class DynamicCommand extends DefaultMutableModule implements
 	@Parameter
 	private PluginService pluginService;
 
+	@Parameter
+	private ModuleService moduleService;
+
 	private DynamicCommandInfo info;
 
 	/** Reason for cancelation, or null if not canceled. */
@@ -160,12 +161,6 @@ public void uncancel() {
 	 * not complete the module execution lifecycle normally.
 	 */
 	protected void saveInputs() {
-		// https://forum.image.sc/t/how-to-save-interactivecommand-parameter-values/26645/5
-		final PluginInfo<PreprocessorPlugin> saveInputsPreprocessorInfo =
-			pluginService.getPlugin(SaveInputsPreprocessor.class,
-				PreprocessorPlugin.class);
-		final PreprocessorPlugin saveInputsPreprocessor = //
-			pluginService.createInstance(saveInputsPreprocessorInfo);
-		saveInputsPreprocessor.process(this);
+		moduleService.saveInputs(this);
 	}
 }

src/main/java/org/scijava/module/DefaultModuleService.java

@@ -339,6 +339,16 @@ public <T> T getDefaultValue(final ModuleItem<T> item) {
 		return null;
 	}
 
+	@Override
+	public void saveInputs(final Module module) {
+		module.getInfo().inputs().forEach(item -> saveInput(module, item));
+	}
+
+	@Override
+	public void loadInputs(final Module module) {
+		module.getInfo().inputs().forEach(item -> loadInput(module, item));
+	}
+
 	// -- Service methods --
 
 	@Override
@@ -523,4 +533,32 @@ private String prefKey(final ModuleItem<?> item) {
 		return persistKey == null || persistKey.isEmpty() ? //
 			item.getName() : persistKey;
 	}
+
+	/** Saves the value of the given module item to persistent storage. */
+	private <T> void saveInput(final Module module, final ModuleItem<T> item) {
+		final T value = item.getValue(module);
+		save(item, value);
+	}
+
+	/** Loads the value of the given module item from persistent storage. */
+	private <T> void loadInput(final Module module, final ModuleItem<T> item) {
+		// skip input that has already been resolved
+		if (module.isInputResolved(item.getName())) return;
+
+		final T prefValue = load(item);
+		final Class<T> type = item.getType();
+		final T defaultValue = item.getValue(module);
+		final T value = getBestValue(prefValue, defaultValue, type);
+		item.setValue(module, value);
+	}
+
+	private <T> T getBestValue(final Object prefValue,
+		final Object defaultValue, final Class<T> type)
+	{
+		if (prefValue != null) return convertService.convert(prefValue, type);
+		if (defaultValue != null) {
+			return convertService.convert(defaultValue, type);
+		}
+		return Types.nullValue(type);
+	}
 }

src/main/java/org/scijava/module/ModuleService.java

@@ -311,4 +311,9 @@ <M extends Module> Future<M> run(M module,
 	/** Gets the default value of the given {@link ModuleItem}. */
 	<T> T getDefaultValue(final ModuleItem<T> item);
 
+	/** Saves values to persistent storage from the given {@link Module}. */
+	void saveInputs(final Module module);
+
+	/** Loads values from persistent storage into the given {@link Module}. */
+	void loadInputs(final Module module);
 }

src/main/java/org/scijava/module/process/LoadInputsPreprocessor.java

@@ -32,13 +32,10 @@
 
 package org.scijava.module.process;
 
-import org.scijava.convert.ConvertService;
 import org.scijava.module.Module;
-import org.scijava.module.ModuleItem;
 import org.scijava.module.ModuleService;
 import org.scijava.plugin.Parameter;
 import org.scijava.plugin.Plugin;
-import org.scijava.util.Types;
 import org.scijava.widget.InputHarvester;
 
 /**
@@ -59,41 +56,8 @@ public class LoadInputsPreprocessor extends AbstractPreprocessorPlugin {
 	@Parameter
 	private ModuleService moduleService;
 
-	@Parameter
-	private ConvertService conversionService;
-
-	// -- ModuleProcessor methods --
-
 	@Override
 	public void process(final Module module) {
-		final Iterable<ModuleItem<?>> inputs = module.getInfo().inputs();
-		for (final ModuleItem<?> item : inputs) {
-			loadValue(module, item);
-		}
-	}
-
-	// -- Helper methods --
-
-	/** Loads the value of the given module item from persistent storage. */
-	private <T> void loadValue(final Module module, final ModuleItem<T> item) {
-		// skip input that has already been resolved
-		if (module.isInputResolved(item.getName())) return;
-
-		final T prefValue = moduleService.load(item);
-		final Class<T> type = item.getType();
-		final T defaultValue = item.getValue(module);
-		final T value = getBestValue(prefValue, defaultValue, type);
-		item.setValue(module, value);
+		moduleService.loadInputs(module);
 	}
-
-	private <T> T getBestValue(final Object prefValue,
-		final Object defaultValue, final Class<T> type)
-	{
-		if (prefValue != null) return conversionService.convert(prefValue, type);
-		if (defaultValue != null) {
-			return conversionService.convert(defaultValue, type);
-		}
-		return Types.nullValue(type);
-	}
-
 }

src/main/java/org/scijava/module/process/SaveInputsPreprocessor.java

@@ -34,7 +34,6 @@
 
 import org.scijava.Priority;
 import org.scijava.module.Module;
-import org.scijava.module.ModuleItem;
 import org.scijava.module.ModuleService;
 import org.scijava.plugin.Parameter;
 import org.scijava.plugin.Plugin;
@@ -59,22 +58,8 @@ public class SaveInputsPreprocessor extends AbstractPreprocessorPlugin {
 	@Parameter
 	private ModuleService moduleService;
 
-	// -- ModuleProcessor methods --
-
 	@Override
 	public void process(final Module module) {
-		final Iterable<ModuleItem<?>> inputs = module.getInfo().inputs();
-		for (final ModuleItem<?> item : inputs) {
-			saveValue(module, item);
-		}
+		moduleService.saveInputs(module);
 	}
-
-	// -- Helper methods --
-
-	/** Saves the value of the given module item to persistent storage. */
-	private <T> void saveValue(final Module module, final ModuleItem<T> item) {
-		final T value = item.getValue(module);
-		moduleService.save(item, value);
-	}
-
 }