Merge branch 'load'

This topic branch offers the load(path) function to import reusable
Javascript libraries. Its absence from the SciJava scripting framework's
Javascript support was bemoaned by Christophe Leterrier.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

pom.xml

@@ -5,7 +5,7 @@
 	<parent>
 		<groupId>org.scijava</groupId>
 		<artifactId>pom-scijava</artifactId>
-		<version>1.167</version>
+		<version>2.20</version>
 		<relativePath />
 	</parent>
 

src/main/java/org/scijava/plugins/scripting/javascript/JavaScriptScriptLanguage.java

@@ -34,6 +34,7 @@
 import java.lang.reflect.InvocationTargetException;
 
 import javax.script.ScriptEngine;
+import javax.script.ScriptException;
 
 import org.scijava.log.LogService;
 import org.scijava.plugin.Parameter;
@@ -58,6 +59,23 @@ public JavaScriptScriptLanguage() {
 		super("javascript");
 	}
 
+	@Override
+	public ScriptEngine getScriptEngine() {
+		final ScriptEngine engine = super.getScriptEngine();
+		try {
+			engine.eval("function load(path) {\n"
+					+ "  importClass(Packages.sun.org.mozilla.javascript.internal.Context);\n"
+					+ "  importClass(Packages.java.io.FileReader);\n"
+					+ "  var cx = Context.getCurrentContext();\n"
+					+ "  cx.evaluateReader(this, new FileReader(path), path, 1, null);\n"
+					+ "}");
+		}
+		catch (ScriptException e) {
+			e.printStackTrace();
+		}
+		return engine;
+	}
+
 	@Override
 	public Object decode(final Object object) {
 		// NB: JavaScript objects come out of the engine wrapped as

src/test/java/org/scijava/plugins/scripting/javascript/JavaScriptTest.java

@@ -35,7 +35,10 @@
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
+import java.io.File;
+import java.io.FileWriter;
 import java.io.IOException;
+import java.io.Writer;
 import java.util.concurrent.ExecutionException;
 
 import javax.script.Bindings;
@@ -109,4 +112,18 @@ public void testParameters() throws InterruptedException, ExecutionException,
 		assertEquals(expected, result);
 	}
 
+	@Test
+	public void testLoad() throws IOException, InterruptedException, ExecutionException, ScriptException {
+		final File tmp = File.createTempFile("js-lib-", ".js");
+		final Writer writer = new FileWriter(tmp);
+		writer.write("function three() { return 4; }");
+		writer.close();
+
+		final Context context = new Context(ScriptService.class);
+		final ScriptService scriptService = context.getService(ScriptService.class);
+		final String script = "load('" + tmp.getPath() + "'); three();";
+		final Object result = scriptService.run("three.js", script, false).get().getReturnValue();
+		assertEquals(4.0, (Number) result);
+		assertTrue(tmp.delete());
+	}
 }