UML.jshell

//%jars /usr/local/bin/plantuml.jar

import io.github.spencerpark.ijava.IJava;
import net.sourceforge.plantuml.*;
import net.sourceforge.plantuml.core.DiagramDescription;
import java.nio.charset.Charset;
import javax.imageio.ImageIO;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import io.github.spencerpark.ijava.IJava;
import io.github.spencerpark.ijava.JavaKernel;
import io.github.spencerpark.jupyter.kernel.magic.registry.UndefinedMagicException;


/**
Render plantUML from cell
*/
IJava.getKernelInstance().getMagics().registerCellMagic("plantUML", (args, body) -> {
        //sets the results mimetype
        if (args.size()>1) throw new Exception("Max one argument : SVG or PNG");
        String fileFormat;
        if (args.size()==0) fileFormat="SVG"; 
          else fileFormat=args.get(0);    
        
        SourceStringReader reader = new SourceStringReader(body);
        final ByteArrayOutputStream os = new ByteArrayOutputStream();

        DiagramDescription desc = reader.outputImage(os, new FileFormatOption(FileFormat.valueOf(fileFormat)));
        os.close();
        Object out;
        if (fileFormat.equals("SVG"))
            out = new String(os.toByteArray(), Charset.forName("UTF-8"));
        else 
            out= ImageIO.read(new ByteArrayInputStream(os.toByteArray()));
        
        display(out,fileFormat.equals("SVG")?"image/svg+xml":"image/png");
        return out;
        });

/**
Render plantUML from file
*/
IJava.getKernelInstance().getMagics().registerCellMagic("plantUMLFile", (args, body) -> {    
    //sets the results mimetype
    if (args.size()>1) throw new Exception("Max one argument : SVG or PNG");
    String fileFormat;
    if (args.size()==0) fileFormat="SVG"; 
    else fileFormat=args.get(0);
    
    List<String> l = new ArrayList<>();

    List<Object> outList = new ArrayList<>();
    body.lines().forEach(filename-> {
     Object out;        
     try {        
        out=cellMagic("plantUML",args,Files.readString(Paths.get(filename)));
        //display(out,fileFormat.equals("SVG")?"image/svg+xml":"image/png");
        outList.add(out);
     } catch (java.io.IOException e) {}
    });    
    
        return outList;
                
        });