Full restructuring of demat to use vega-lite spec directly with JAVET…

… instead of maintaining a pojo

All vega-lite examples work except image loading, which is not supported.

pom.xml

@@ -3,9 +3,9 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>org.orbisgis</groupId>
     <artifactId>demat</artifactId>
-    <version>0.0.8-SNAPSHOT</version>
+    <version>1.0.0-SNAPSHOT</version>
     <packaging>jar</packaging>
-    <description>Demat is breton word to said "Hello". Demat is wrapper on top of the Vega-lite library</description>
+    <description>Demat is breton word to said "Hello". Demat is library to run Vega-lite specifications.</description>
     <!-- Properties -->
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

readme.md

@@ -6,26 +6,30 @@ Demat is a French Brittany word to said Hello (http://devri.bzh/dictionnaire/d/d
 
 Demat is a java library to generate [Vega-lite](https://vega.github.io/vega-lite/) representations.
 
-
-Demat is under active development, nothing is stable ;-)
+Demat uses the JAVET library to execute JS code.
 
 
 # Use it
 
-Let's run this script with Groovy
+Let's run this script with Groovy to draw a simple bar chart and save it in a svg file.
 
 ```groovy
 @GrabResolver(name = 'orbisgis', root = 'https://oss.sonatype.org/content/repositories/snapshots/')
-@Grab(group = 'org.orbisgis', module = 'demat', version = '0.0.7-SNAPSHOT')
+@Grab(group = 'org.orbisgis', module = 'demat', version = '1.0.0-SNAPSHOT')
 
 import static org.orbisgis.demat.Demat.*
 
-def chart = Chart().description("A simple bar chart").name("A simple name")
-        .data(new Object[][]{{"a", "b", "c"}, {1, 22, 12}, {200, 300, 400}})
-        .mark(Bar())
-        .encode(X("a").nominal(), Y("b").quantitative())
-chart.show()
+def spec = [
+        description:"A simple bar chart with embedded data.",
+        data: [values: [
+                ["a": "A", "b": 28], ["a": "B", "b": 55], ["a": "C", "b": 43],
+                ["a": "D", "b": 91], ["a": "E", "b": 81], ["a": "F", "b": 53],
+                ["a": "G", "b": 19], ["a": "H", "b": 87], ["a": "I", "b": 52]]
+        ],
+        mark:"bar",
+        encoding : [x : [field:"a",axis:[LabelAngle:0],type:"nominal"],
+                    y:  [field:"b","type":"quantitative"]]]
+toSVG(spec,  "/tmp/bar_chart.svg")
 ```
 
-shows https://vega.github.io/vega-lite/examples/bar.html
-
+shows https://vega.github.io/vega-lite/examples/bar.html

src/main/java/org/orbisgis/demat/FileUtils.java

@@ -1,6 +1,56 @@
+/*
+ * DEMAT is java wrapper on top of the vega-lite library
+ *
+ * Demat is breton word to said "Hello".
+ *
+ * DEMAT is part of the OrbisGIS platform.
+ *
+ * OrbisGIS platform is a set of open source tools to access, process, display
+ * and share geographical informations.
+ *
+ * It is leaded by CNRS within the French Lab-STICC laboratory <http://www.lab-sticc.fr/>,
+ * DECIDE team of Vannes.
+ *
+ * OrbisGIS is dedicated to research in GIScience.
+ *
+ * The GIS group of the DECIDE team is located at :
+ *
+ * Laboratoire Lab-STICC – CNRS UMR 6285
+ * Equipe DECIDE
+ * UNIVERSITÉ DE BRETAGNE-SUD
+ * Institut Universitaire de Technologie de Vannes
+ * 8, Rue Montaigne - BP 561 56017 Vannes Cedex
+ *
+ * DEMAT is distributed under LGPL 3 license.
+ *
+ * Copyright (C) 2021 CNRS (Lab-STICC UMR CNRS 6285)
+ *
+ *
+ * DEMAT 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.
+ *
+ * DEMAT is 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
+ * DEMAT. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * For more information, please consult: <http://www.orbisgis.org/>
+ * or contact directly:
+ * info_at_ orbisgis.org
+ */
 package org.orbisgis.demat;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+
 import java.io.*;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 
 public class FileUtils {
 
@@ -90,4 +140,171 @@ public static boolean isExtensionWellFormated(File file, String... prefixes) {
         }
         return false;
     }
+
+    /**
+     *
+     * @param reader
+     * @return
+     * @throws IOException
+     */
+    public static Object json(InputStream reader)  {
+        ObjectMapper mapper = new ObjectMapper();
+        try {
+            return mapper.readValue(reader, Object.class);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    /**
+     *
+     * @param jsonFile
+     * @return
+     * @throws IOException
+     */
+    public static Object json(File jsonFile) throws IOException {
+        if(FileUtils.isExtensionWellFormated(jsonFile, "json", "geojson")) {
+            ObjectMapper mapper = new ObjectMapper();
+            return mapper.readValue(jsonFile, Object.class);
+        }
+        throw new RuntimeException("Cannot read as json file.");
+    }
+
+    /**
+     *
+     * @param jsonFile
+     * @return
+     * @throws IOException
+     */
+    public static Object geojson(File jsonFile) throws IOException {
+        if(FileUtils.isExtensionWellFormated(jsonFile,  "json", "geojson")) {
+            ObjectMapper mapper = new ObjectMapper();
+            return mapper.readValue(jsonFile, Object.class);
+        }
+        throw new RuntimeException("Cannot read as json file.");
+    }
+
+
+    /**
+     * Read a CSV {@link File} and convert it to a Data object
+     * @param csvFile
+     * @return
+     * @throws IOException
+     */
+    public static List csv(File csvFile) throws IOException {
+        if(FileUtils.isExtensionWellFormated(csvFile,  "csv")) {
+            String line = "";
+            //use comma as separator
+            String splitBy = ",";
+
+            ArrayList lines = new ArrayList();
+            try (BufferedReader br =
+                         new BufferedReader(new FileReader(csvFile))) {
+
+                //Header
+                line = br.readLine();
+                String[] header = null;
+                if (line != null) {
+                    header = line.split(splitBy);
+                }
+                while ((line = br.readLine()) != null) {
+                    Map<String, Object> values = new HashMap<>();
+                    String[] csvValues = line.split(splitBy);
+                    for (int i = 0; i < header.length; i++) {
+                        values.put(header[i], csvValues[i]);
+                    }
+                    lines.add(values);
+                }
+            }
+
+            return lines;
+        }
+        return null;
+    }
+    /**
+     * Read a CSV {@link File} and convert it to a Data object
+     * @param tsvFile
+     * @return
+     * @throws IOException
+     */
+    public static List tsv(File tsvFile) throws IOException {
+        if(FileUtils.isExtensionWellFormated(tsvFile,  "tsv")) {
+            String line = "";
+            //use tabular as separator
+            String splitBy = "\t";
+            ArrayList lines = new ArrayList();
+            try (BufferedReader br =
+                         new BufferedReader(new FileReader(tsvFile))) {
+                //Header
+                line = br.readLine();
+                String[] header = null;
+                if (line != null) {
+                    header = line.split(splitBy);
+                }
+                while ((line = br.readLine()) != null) {
+                    Map<String, Object> values = new HashMap<>();
+                    String[] csvValues = line.split(splitBy);
+                    for (int i = 0; i < header.length; i++) {
+                        values.put(header[i], csvValues[i]);
+                    }
+                    lines.add(values);
+                }
+            }
+            return lines;
+        }
+        return null;
+    }
+
+    /**
+     * Method to open a browser
+     * Used by ImageJ
+     *
+     * @param url
+     * @throws Exception
+     */
+    public static void openBrowser(String url) throws Exception {
+        if (url == null || url.isEmpty()) {
+            throw new RuntimeException("The URL cannot be null or empty");
+        }
+        String osname = System.getProperty("os.name");
+        boolean isWin = osname.startsWith("windows");
+        boolean isMac = !isWin && osname.startsWith("mac");
+        if (isMac) {
+            Runtime.getRuntime().exec("open " + url);
+        } else if (isWin) {
+            String cmd = "rundll32 url.dll,FileProtocolHandler " + url;
+            if (osname.startsWith("Windows 2000"))
+                cmd = "rundll32 shell32.dll,ShellExec_RunDLL " + url;
+            Process process = Runtime.getRuntime().exec(cmd);
+            // This avoids a memory leak on some versions of Java on Windows.
+            // That's hinted at in <http://developer.java.sun.com/developer/qow/archive/68/>.
+            try {
+                process.waitFor();
+                process.exitValue();
+            } catch (InterruptedException ie) {
+                throw new IOException("InterruptedException while launching browser: " + ie.getMessage());
+            }
+        } else {
+            // Assume Linux or Unix
+            // Based on BareBonesBrowserLaunch (http://www.centerkey.com/java/browser/)
+            // The utility 'xdg-open' launches the URL in the user's preferred browser,
+            // therefore we try to use it first, before trying to discover other browsers.
+            String[] browsers = {"xdg-open", "netscape", "firefox", "konqueror", "mozilla", "opera", "epiphany", "lynx"};
+            String browserName = null;
+            try {
+                for (int count = 0; count < browsers.length && browserName == null; count++) {
+                    String[] c = new String[]{"which", browsers[count]};
+                    if (Runtime.getRuntime().exec(c).waitFor() == 0)
+                        browserName = browsers[count];
+                }
+                if (browserName == null) {
+                    throw new RuntimeException("Could not find a browser");
+                } else {
+                    Runtime.getRuntime().exec(new String[]{browserName, url});
+                }
+            } catch (Exception e) {
+                throw new IOException("Exception while launching browser: " + e.getMessage());
+            }
+        }
+    }
 }