Merge pull request #755 from arittner/aritner-loadJSON

Introduction of an internal function %loadJSON to load JSON data

src/net/sourceforge/plantuml/tim/TContext.java

@@ -106,6 +106,7 @@ import net.sourceforge.plantuml.tim.stdlib.InvokeProcedure;
 import net.sourceforge.plantuml.tim.stdlib.IsDark;
 import net.sourceforge.plantuml.tim.stdlib.IsLight;
 import net.sourceforge.plantuml.tim.stdlib.Lighten;
+import net.sourceforge.plantuml.tim.stdlib.LoadJson;
 import net.sourceforge.plantuml.tim.stdlib.LogicalNot;
 import net.sourceforge.plantuml.tim.stdlib.Lower;
 import net.sourceforge.plantuml.tim.stdlib.Newline;
@@ -177,6 +178,7 @@ public class TContext {
 		functionsSet.addFunction(new Hex2dec());
 		functionsSet.addFunction(new Dec2hex());
 		functionsSet.addFunction(new HslColor());
+		functionsSet.addFunction(new LoadJson());
 		functionsSet.addFunction(new Chr());
 		functionsSet.addFunction(new Size());
 		// %standard_exists_function

src/net/sourceforge/plantuml/tim/stdlib/LoadJson.java

@@ -0,0 +1,186 @@
+/* ========================================================================
+ * PlantUML : a free UML diagram generator
+ * ========================================================================
+ *
+ * (C) Copyright 2009-2021, Arnaud Roques
+ *
+ * Project Info:  http://plantuml.com
+ *
+ * If you like this project or if you find it useful, you can support us at:
+ *
+ * http://plantuml.com/patreon (only 1$ per month!)
+ * http://plantuml.com/paypal
+ *
+ * This file is part of PlantUML.
+ *
+ * PlantUML is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * PlantUML distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
+ * USA.
+ *
+ *
+ * Original Author:  Arnaud Roques
+ *
+ */
+package net.sourceforge.plantuml.tim.stdlib;
+
+import net.sourceforge.plantuml.FileSystem;
+import net.sourceforge.plantuml.FileUtils;
+import net.sourceforge.plantuml.LineLocation;
+import net.sourceforge.plantuml.json.Json;
+import net.sourceforge.plantuml.json.JsonValue;
+import net.sourceforge.plantuml.json.ParseException;
+import net.sourceforge.plantuml.security.SFile;
+import net.sourceforge.plantuml.security.SURL;
+import net.sourceforge.plantuml.tim.*;
+import net.sourceforge.plantuml.tim.expression.TValue;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Loads JSON data from file or URL source.
+ * <p>
+ * Supports three parameters for datasource, default JSON value and charset. The datasource will be checked against
+ * the security rules.
+ * <p>
+ * Examples:</br>
+ * <pre>
+ *     @ startuml
+ *     ' loads a local file
+ *     !$JSON_LOCAL_RELATIVE=%loadJSON("file.json")
+ *
+ *     ' loads a local file from an absolute file path
+ *     !$JSON_LOCAL_ABS=%loadJSON("c:/loaded/data/file.json")
+ *
+ *     ' tries to load a local file and returns an empty JSON
+ *     !$JSON_LOCAL_REL_EMPTY=%loadJSON("file-not-existing.json")
+ *
+ *     ' tries to load a local file and returns an default JSON
+ *     !$DEF_JSON={"status":"No data found"}
+ *     !$JSON_LOCAL_REL_DEF=%loadJSON("file-not-existing.json", $DEF_JSON)
+ *
+ *     ' loads a local file with a specific charset (default is UTF-8)
+ *     !$JSON_LOCAL_RELATIVE_CHARSET=%loadJSON("file.json", "{}", "iso-8859-1")
+ *
+ *     ' loads a remote JSON from an endpoint (and default, if not reachable)
+ *     !$STATUS_NO_CONNECTION={"status": "No connection"}
+ *     !$JSON_REMOTE_DEF=%loadJSON("https://localhost:7778/management/health", $STATUS_NO_CONNECTION)
+ *     status -> $JSON_REMOTE_DEF.status
+ *     @ enduml
+ * </pre>
+ * @author Aljoscha Rittner
+ */
+public class LoadJson extends SimpleReturnFunction {
+
+	private static final String VALUE_CHARSET_DEFAULT = "UTF-8";
+
+	private static final String VALUE_DEFAULT_DEFAULT = "{}";
+
+	public TFunctionSignature getSignature() {
+		return new TFunctionSignature("%loadJSON", 3 );
+	}
+
+	public boolean canCover(int nbArg, Set<String> namedArgument) {
+		return nbArg == 1 || nbArg == 2 || nbArg == 3;
+	}
+
+	public TValue executeReturnFunction(TContext context, TMemory memory, LineLocation location, List<TValue> values,
+			Map<String, TValue> named) throws EaterException, EaterExceptionLocated {
+		String path = values.get(0).toString();
+		try {
+			String data = loadStringData ( path, getCharset (values) );
+			if ( data == null ) {
+				data = getDefaultJson(values);
+			}
+			JsonValue jsonValue = Json.parse(data);
+			return TValue.fromJson(jsonValue);
+		} catch (ParseException pe) {
+			pe.printStackTrace ();
+			throw EaterException.unlocated ( "JSON parse issue in source "
+				+ path + " on location " +  pe.getLocation () );
+		} catch (UnsupportedEncodingException e) {
+			e.printStackTrace ();
+			throw EaterException.unlocated ( "JSON encoding issue in source "
+				+ path + ": " + e.getMessage () );
+		}
+	}
+
+	/**
+	 * Returns the JSON default, if the data source contains no data.
+	 * @param values value parameters
+	 * @return the defined default JSON or {@code "{}"}
+	 */
+	private String getDefaultJson(List<TValue> values) {
+		if (values.size() > 1 ) {
+			return values.get(1).toString ();
+		}
+		return VALUE_DEFAULT_DEFAULT;
+	}
+
+	/**
+	 * Returns the charset name (if set)
+	 * @param values value parameters
+	 * @return defined charset or {@code "UTF-8"}
+	 */
+	private String getCharset(List<TValue> values) {
+		if ( values.size() == 3) {
+			return values.get (2).toString ();
+		}
+		return VALUE_CHARSET_DEFAULT;
+	}
+
+	/**
+	 * Loads String data from a data source {@code path} (file or URL) and expects the data encoded in {@code charset}.
+	 * @param path path to data source (http(s)-URL or file).
+	 * @param charset character set to encode the string data
+	 * @return the decoded String from the data source
+	 * @throws EaterException if something went wrong on reading data
+	 */
+	private String loadStringData(String path, String charset) throws EaterException, UnsupportedEncodingException {
+
+		byte[] byteData = null;
+		if (path.startsWith("http://") || path.startsWith("https://")) {
+			final SURL url = SURL.create(path);
+			if (url == null) {
+				throw EaterException.located("load JSON: Invalid URL " + path);
+			}
+			byteData = url.getBytes();
+			if (byteData != null && byteData.length == 0) {
+				// no length, no data (we want the default)
+				byteData = null;
+			}
+		} else {
+			try {
+				SFile file = FileSystem.getInstance().getFile(path);
+				if (file != null && file.exists() && file.canRead() && !file.isDirectory()) {
+					ByteArrayOutputStream out = new ByteArrayOutputStream(1024 * 8);
+					FileUtils.copyToStream(file, out);
+					byteData = out.toByteArray();
+				}
+			} catch (IOException e) {
+				e.printStackTrace();
+				throw EaterException.located("load JSON: Cannot read file "
+						+ path + ". " + e.getMessage());
+			}
+		}
+		if (byteData != null) {
+			return new String(byteData, charset);
+		}
+		return null;
+	}
+}

test/net/sourceforge/plantuml/LoadJsonTest.java

@@ -0,0 +1,140 @@
+package net.sourceforge.plantuml;
+
+import net.sourceforge.plantuml.security.SFile;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import java.nio.file.Path;
+import java.util.Collections;
+import java.util.List;
+
+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 static org.assertj.core.util.Lists.newArrayList;
+
+/**
+ * Tests the load of a JSON file.
+ * <p>
+ * Current limitation: Only local file tests, not tests to a http rest endpoint
+ */
+class LoadJsonTest {
+
+    private static final String[] COMMON_OPTIONS = {"-tutxt"};
+
+    private static final String JSON = "{\"jsonTestKey\": \"exampleValue\"}";
+
+    private static final String DEF_JSON = "{\"jsonTestKey\": \"exampleDefaultValue\"}";
+
+    // ************ Test DSL data
+    private static final String DIAGRAM = "" +
+            "@startuml\n" +
+            "!$JSON_DATA=%loadJSON(test.json)\n" +
+
+            // title should have the value from the JSON file
+            "title $JSON_DATA.jsonTestKey\n" +
+            "a -> b\n" +
+            "@enduml\n";
+
+    private static final String DIAGRAM_DEF = "" +
+            "@startuml\n" +
+            "!$DEF_JSON=" + DEF_JSON + "\n" +
+            "!$JSON_DATA=%loadJSON(\"test-notfound.json\", $DEF_JSON)\n" +
+
+            // title should have the value from the default (because the file doesn't exist)
+            "title $JSON_DATA.jsonTestKey\n" +
+            "a -> b\n" +
+            "@enduml\n";
+
+    private static final String DIAGRAM_DEF_EMPTY = "" +
+            "@startuml\n" +
+            "!$JSON_DATA=%loadJSON(\"test-notfound.json\")\n" +
+            // JSON_DATA is defined, but empty (loadJSON default). So, title contains only  "xx  yy".
+            "title xx $JSON_DATA.jsonTestKey yy\n" +
+            "a -> b\n" +
+            "@enduml\n";
+
+
+    @TempDir
+    Path tempDir;
+
+    /**
+     * Resets the current directory.
+     */
+    @AfterAll
+    static void cleanUp() {
+        FileSystem.getInstance().reset();
+    }
+
+    /**
+     * Prepares test JSON file and sets the current directory for each test.
+     *
+     * @throws Exception hopefully not
+     */
+    @BeforeEach
+    public void beforeEach() throws Exception {
+        writeUtf8File(tempDir.resolve("test.json"), JSON);
+        FileSystem.getInstance().setCurrentDir(new SFile(tempDir.toFile().getAbsolutePath()));
+    }
+
+    /**
+     * Tests, if the loadJSON is loading the JSON file from test tmp folder.
+     *
+     * @throws Exception if something went wrong in this test
+     */
+    @Test
+    void testLoadJsonSimple() throws Exception {
+        String rendered = render(DIAGRAM);
+        assertThat(rendered).doesNotContain("syntax").contains("exampleValue");
+
+    }
+
+    /**
+     * Tests, if the loadJSON is using the default JSON given as parameter.
+     *
+     * @throws Exception if something went wrong in this test
+     */
+    @Test
+    void testLoadJsonNotFoundWithDefaultParameter() throws Exception {
+        String rendered = render(DIAGRAM_DEF);
+        assertThat(rendered).doesNotContain("syntax").contains("exampleDefaultValue");
+    }
+
+    /**
+     * Tests, if the loadJSON is using the default JSON.
+     *
+     * @throws Exception if something went wrong in this test
+     */
+    @Test
+    void testLoadJsonNotFoundWithDefaultEmpty() throws Exception {
+        String rendered = render(DIAGRAM_DEF_EMPTY);
+        assertThat(rendered).doesNotContain("syntax").contains("xx  yy");
+    }
+
+    private String[] optionArray(String... extraOptions) {
+        final List<String> list = newArrayList(COMMON_OPTIONS);
+        Collections.addAll(list, extraOptions);
+        return list.toArray(new String[0]);
+    }
+
+    private String render(String diagram, 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);
+    }
+
+}