org.scijava.script.ScriptModule Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of scijava-common Show documentation
Show all versions of scijava-common Show documentation
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.
/*
* #%L
* SciJava Common shared library for SciJava software.
* %%
* Copyright (C) 2009 - 2016 Board of Regents of the University of
* Wisconsin-Madison, Broad Institute of MIT and Harvard, and Max Planck
* Institute of Molecular Cell Biology and Genetics.
* %%
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
* #L%
*/
package org.scijava.script;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.Writer;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptException;
import org.scijava.Context;
import org.scijava.Contextual;
import org.scijava.NullContextException;
import org.scijava.convert.ConvertService;
import org.scijava.log.LogService;
import org.scijava.module.AbstractModule;
import org.scijava.module.Module;
import org.scijava.module.ModuleItem;
import org.scijava.plugin.Parameter;
import org.scijava.util.FileUtils;
/**
* A {@link Module} which executes a script.
*
* @author Curtis Rueden
* @author Johannes Schindelin
*/
public class ScriptModule extends AbstractModule implements Contextual {
public static final String RETURN_VALUE = "result";
private final ScriptInfo info;
@Parameter
private Context context;
@Parameter
private ScriptService scriptService;
@Parameter
private ConvertService conversionService;
@Parameter
private LogService log;
/** Script language in which the script should be executed. */
private ScriptLanguage scriptLanguage;
/** Script engine with which the script should be executed. */
private ScriptEngine scriptEngine;
/** Destination for standard output during script execution. */
private Writer output;
/** Destination for standard error during script execution. */
private Writer error;
private Object returnValue;
public ScriptModule(final ScriptInfo info) {
this.info = info;
}
// -- ScriptModule methods --
/** Gets the scripting language of the script. */
public ScriptLanguage getLanguage() {
if (scriptLanguage == null) {
// infer the language from the script path's extension
final String path = getInfo().getPath();
final String extension = FileUtils.getExtension(path);
scriptLanguage = scriptService.getLanguageByExtension(extension);
}
return scriptLanguage;
}
/** Overrides the script language to use when executing the script. */
public void setLanguage(final ScriptLanguage scriptLanguage) {
this.scriptLanguage = scriptLanguage;
}
/** Sets the writer used to record the standard output stream. */
public void setOutputWriter(final Writer output) {
this.output = output;
}
/** Sets the writer used to record the standard error stream. */
public void setErrorWriter(final Writer error) {
this.error = error;
}
/** Gets the script engine used to execute the script. */
public ScriptEngine getEngine() {
if (scriptEngine == null) {
scriptEngine = getLanguage().getScriptEngine();
}
return scriptEngine;
}
/** Gets the return value of the script. */
public Object getReturnValue() {
return returnValue;
}
// -- Module methods --
@Override
public ScriptInfo getInfo() {
return info;
}
// -- Runnable methods --
@Override
public void run() {
final ScriptEngine engine = getEngine();
final String path = getInfo().getPath();
// initialize the script engine
engine.put(ScriptEngine.FILENAME, path);
engine.put(ScriptModule.class.getName(), this);
final ScriptContext scriptContext = engine.getContext();
if (output != null) scriptContext.setWriter(output);
final PrintWriter errorPrinter;
if (error != null) {
scriptContext.setErrorWriter(error);
errorPrinter = new PrintWriter(error);
} else {
errorPrinter = null;
}
// populate bindings with the input values
for (final ModuleItem item : getInfo().inputs()) {
final String name = item.getName();
engine.put(name, getInput(name));
}
// execute script!
returnValue = null;
try {
final Reader reader = getInfo().getReader();
if (reader == null) returnValue = engine.eval(new FileReader(path));
else returnValue = engine.eval(reader);
}
catch (Throwable e) {
while (e instanceof ScriptException && e.getCause() != null) {
e = e.getCause();
}
if (error == null) {
log.error(e);
} else {
e.printStackTrace(errorPrinter);
}
}
// populate output values
final ScriptLanguage language = getLanguage();
for (final ModuleItem item : getInfo().outputs()) {
final String name = item.getName();
if (isResolved(name)) continue;
final Object value;
if (RETURN_VALUE.equals(name) && getInfo().isReturnValueAppended()) {
// NB: This is the special implicit return value output!
value = returnValue;
}
else value = engine.get(name);
final Object decoded = language.decode(value);
final Object typed = conversionService.convert(decoded, item.getType());
setOutput(name, typed);
setResolved(name, true);
}
// flush output and error streams
if (output != null) {
try {
output.flush();
}
catch (final IOException e) {
if (error == null) log.error(e);
else e.printStackTrace(errorPrinter);
}
}
if (errorPrinter != null) errorPrinter.flush();
}
// -- Contextual methods --
@Override
public Context context() {
if (context == null) throw new NullContextException();
return context;
}
@Override
public Context getContext() {
return context;
}
@Override
public void setContext(final Context context) {
context.inject(this);
}
}