Add -filedir option.

pom.xml

@@ -77,6 +77,12 @@
             <version>1.10.9</version>
             <scope>provided</scope>
         </dependency>
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-lang3</artifactId>
+			<version>3.12.0</version>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.assertj</groupId>
 			<artifactId>assertj-core</artifactId>

src/net/sourceforge/plantuml/Option.java

@@ -85,6 +85,7 @@ public class Option {
 	private boolean checkMetadata = false;
 	private int stdrpt = 0;
 	private int imageIndex = 0;
+	private String fileDir;
 
 	private File outputDir = null;
 	private File outputFile = null;
@@ -188,6 +189,12 @@ public class Option {
 					continue;
 				}
 				filename = StringUtils.eventuallyRemoveStartingAndEndingDoubleQuote(arg[i]);
+			} else if (s.equalsIgnoreCase("-filedir")) {
+				i++;
+				if (i == arg.length) {
+					continue;
+				}
+				fileDir = StringUtils.eventuallyRemoveStartingAndEndingDoubleQuote(arg[i]);
 			} else if (s.startsWith("-o") && s.length() > 3) {
 				s = s.substring(2);
 				outputDir = new File(StringUtils.eventuallyRemoveStartingAndEndingDoubleQuote(s));
@@ -670,4 +677,7 @@ public class Option {
 	// this.preprocessorOutput = preprocessorOutput;
 	// }
 
+	public String getFileDir() {
+		return fileDir;
+	}
 }

src/net/sourceforge/plantuml/OptionPrint.java

@@ -153,6 +153,7 @@ public class OptionPrint {
 		System.out.println("    -pipeimageindex N\tTo generate the Nth image with pipe option");
 		System.out.println("    -stdlib\t\tTo print standard library info");
 		System.out.println("    -extractstdlib\tTo extract PlantUML Standard Library into stdlib folder");
+		System.out.println("    -filedir xxx\tTo behave as if the PlantUML source is in this dir (only affects '-pipe' and PicoWeb 'POST /render')");
 		System.out.println("    -filename \"example.puml\"\tTo override %filename% variable");
 		System.out.println("    -preproc\t\tTo output preprocessor text of diagrams");
 		System.out.println("    -cypher\t\tTo cypher texts of diagrams so that you can share them");

src/net/sourceforge/plantuml/Pipe.java

@@ -46,6 +46,7 @@ import net.sourceforge.plantuml.core.Diagram;
 import net.sourceforge.plantuml.core.DiagramDescription;
 import net.sourceforge.plantuml.error.PSystemError;
 import net.sourceforge.plantuml.preproc.Defines;
+import net.sourceforge.plantuml.security.SFile;
 
 public class Pipe {
 
@@ -78,7 +79,9 @@ public class Pipe {
 			}
 			nb++;
 			final Defines defines = option.getDefaultDefines();
-			final SourceStringReader sourceStringReader = new SourceStringReader(defines, source, option.getConfig());
+			final SFile newCurrentDir = option.getFileDir() == null ? null : new SFile(option.getFileDir());
+			final SourceStringReader sourceStringReader = new SourceStringReader(defines, source, "UTF-8",
+					option.getConfig(), newCurrentDir);
 			if (option.isComputeurl()) {
 				for (BlockUml s : sourceStringReader.getBlocks()) {
 					ps.println(s.getEncodedUrl());

src/net/sourceforge/plantuml/picoweb/PicoWebServer.java

@@ -68,6 +68,7 @@ import net.sourceforge.plantuml.core.ImageData;
 import net.sourceforge.plantuml.error.PSystemError;
 import net.sourceforge.plantuml.error.PSystemErrorUtils;
 import net.sourceforge.plantuml.graphic.QuoteUtils;
+import net.sourceforge.plantuml.security.SFile;
 import net.sourceforge.plantuml.version.Version;
 
 public class PicoWebServer implements Runnable {
@@ -174,13 +175,20 @@ public class PicoWebServer implements Runnable {
 		} catch (Exception e) {
 			throw new BadRequest400("Error parsing request json: " + e.getMessage(), e);
 		}
+		
+		handleRenderRequest(renderRequest, out);
+	}
+	
+	public void handleRenderRequest(RenderRequest renderRequest, BufferedOutputStream out) throws Exception {
 
 		final Option option = new Option(renderRequest.getOptions());
 
 		final String source = renderRequest.getSource().startsWith("@start") ? renderRequest.getSource()
 				: "@startuml\n" + renderRequest.getSource() + "\n@enduml";
 
-		final SourceStringReader ssr = new SourceStringReader(option.getDefaultDefines(), source, option.getConfig());
+		final SFile newCurrentDir = option.getFileDir() == null ? null : new SFile(option.getFileDir());
+		final SourceStringReader ssr = new SourceStringReader(option.getDefaultDefines(), source, "UTF-8",
+				option.getConfig(), newCurrentDir);
 		final ByteArrayOutputStream os = new ByteArrayOutputStream();
 		final Diagram system;
 		final ImageData imageData;
@@ -258,4 +266,4 @@ public class PicoWebServer implements Runnable {
 		os.write(s.getBytes("UTF-8"));
 	}
 
-}
+}

test/net/sourceforge/plantuml/TestFileDirOption.java

@@ -0,0 +1,116 @@
+package net.sourceforge.plantuml;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static net.sourceforge.plantuml.test.TestUtils.writeUtf8File;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.BufferedOutputStream;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import java.nio.file.Path;
+
+import org.apache.commons.lang3.ArrayUtils;
+import org.apache.commons.lang3.StringUtils;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import net.sourceforge.plantuml.picoweb.PicoWebServer;
+import net.sourceforge.plantuml.picoweb.RenderRequest;
+
+public class TestFileDirOption {
+
+	@TempDir
+	Path tempDir;
+
+	@BeforeEach
+	public void beforeEach() throws Exception {
+
+		writeUtf8File(tempDir.resolve("include.iuml"), INCLUDE);
+	}
+
+	//
+	// Test Cases
+	//
+
+	@Test
+	public void test_picoweb_without_filedir_cannot_find_include() throws Exception {
+
+		final String output = renderViaPicoWeb();
+		assertThat(output).contains("cannot include include.iuml");
+	}
+
+	@Test
+	public void test_picoweb_with_filedir_succeeds() throws Exception {
+
+		final String output = renderViaPicoWeb("-filedir", tempDir.toString());
+		assertThat(output).contains("included-ok");
+	}
+
+
+	@Test
+	public void test_pipe_without_filedir_cannot_find_include() throws Exception {
+
+		final String output = renderViaPipe();
+		assertThat(output).contains("cannot include include.iuml");
+	}
+
+	@Test
+	public void test_pipe_with_filedir_succeeds() throws Exception {
+
+		final String output = renderViaPipe("-filedir", tempDir.toString());
+		assertThat(output).contains("included-ok");
+	}
+
+	//
+	// Test DSL
+	//
+
+	private static final String[] COMMON_OPTIONS = {"-tutxt"};
+
+	private static final String DIAGRAM = "" +
+			"@startuml\n" +
+			"!include include.iuml\n" +
+			"a -> b\n" +
+			"@enduml\n";
+
+	private static final String INCLUDE = "title included-ok\n";
+
+
+	private String[] optionArray(String... extraOptions) {
+
+		return ArrayUtils.addAll(COMMON_OPTIONS, extraOptions);
+	}
+
+	private String renderViaPicoWeb(String... extraOptions) throws Exception {
+
+		final RenderRequest renderRequest = new RenderRequest(optionArray(extraOptions), DIAGRAM);
+
+		final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+
+		final PicoWebServer picoWebServer = new PicoWebServer(null);
+
+		picoWebServer.handleRenderRequest(renderRequest, new BufferedOutputStream(baos));
+
+		final String httpResponse = new String(baos.toByteArray(), UTF_8);
+
+		return StringUtils.substringAfter(httpResponse, "\n\r\n");
+	}
+
+	private String renderViaPipe(String... extraOptions) throws Exception {
+
+		final Option option = new Option(optionArray(extraOptions));
+
+		final ByteArrayInputStream bais = new ByteArrayInputStream(DIAGRAM.getBytes(UTF_8));
+
+		final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+
+		final Pipe pipe = new Pipe(option, new PrintStream(baos), bais, option.getCharset());
+
+		pipe.managePipe(ErrorStatus.init());
+
+		return new String(baos.toByteArray(), UTF_8);
+	}
+
+}

test/net/sourceforge/plantuml/test/TestUtils.java

@@ -0,0 +1,16 @@
+package net.sourceforge.plantuml.test;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class TestUtils {
+
+	public static void writeUtf8File(Path path, String string) throws IOException {
+
+		Files.createDirectories(path.getParent());
+		Files.write(path, string.getBytes(UTF_8));
+	}
+}