UploadField

Extension of the Vaadin Upload component to allow usage in forms and enhance multi file uploads.

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Extension of the Vaadin Upload component to allow usage in forms and enhance multi file uploads.

Core class is org.vaadin.addons.thshsh.upload.UploadField. By default this class uses the com.vaadin.flow.component.upload.receivers.MultiFileBuffer receiver, which can be overridden with other receivers like so:

new UploadField(new MultiFileMemoryBuffer())

There is very little reason to use any Receiver other than MultiFileBuffer or MultiFileMemoryBuffer, as the UploadField itself supports limiting the maxFiles to 1 regardless of the underlying receiver implementation.

Features and Enhancements

• Field can be used with Binder to read/write a collection of org.vaadin.addons.thshsh.upload.UploadFile objects on an entity.
• UploadFile POJO holds all necessary properties to work with the uploaded data
• Disallow duplicate file names
• Field Value can be set on sever side even if no data has been uploaded to allow user to delete file references
• Temp Directory can be overridden
• Temp files can preserve upload file name and extension

        UploadField field = new UploadField();
        
        //override some defaults
        field.setAllowDuplicateNames(true); //default is false
        field.setTempDirectory(Files.createTempDirectory("mytempdir").toFile());   //default auto generates temp dir
        field.setPreserveFileNames(true); //default is false, which uses temp file names
        field.setMaxFiles(5);  //default is null (no-limit)
        field.setAutoUpload(false);  //default is true
        
        //Can set values without data to allow user to manipulate
        List<UploadFile> files = List.of(new UploadFile(new FileData("serverfile.txt","txt",new ByteArrayOutputStream()),null));
        field.setValue(files);

Sample code

package org.vaadin.addons.thshsh.upload;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.List;

import com.vaadin.flow.component.button.Button;
import com.vaadin.flow.component.html.Hr;
import com.vaadin.flow.component.html.Span;
import com.vaadin.flow.component.orderedlayout.VerticalLayout;
import com.vaadin.flow.component.upload.receivers.FileData;
import com.vaadin.flow.component.upload.receivers.MemoryBuffer;
import com.vaadin.flow.component.upload.receivers.MultiFileBuffer;
import com.vaadin.flow.component.upload.receivers.MultiFileMemoryBuffer;
import com.vaadin.flow.data.binder.Binder;
import com.vaadin.flow.data.binder.ValidationException;
import com.vaadin.flow.router.Route;

@Route("")
public class AddonView extends VerticalLayout {

    private static final long serialVersionUID = -5828371605864015426L;
    
   
    public AddonView() throws IOException {
        
       

        
        add(new Span(MemoryBuffer.class.getSimpleName()+", AutoUpload=true, MaxFiles=1"));
        UploadField field = addUploadField(new UploadField(new MemoryBuffer()));
        
        add(new Span(MultiFileBuffer.class.getSimpleName()+", AutoUpload=true, MaxFiles=4"));
        field = addUploadField(new UploadField());
        field.setMaxFiles(4);
        
        add(new Span(MultiFileBuffer.class.getSimpleName()+", AutoUpload=true, MaxFiles=1"));
        field = addUploadField(new UploadField());
        field.setMaxFiles(1);
        
        add(new Span(MultiFileMemoryBuffer.class.getSimpleName()+", AutoUpload=false, MaxFiles=3"));
        field = addUploadField(new UploadField(new MultiFileMemoryBuffer()));
        field.setAutoUpload(false);
        field.setMaxFiles(3);
        

        add(new Span(MultiFileBuffer.class.getSimpleName()+", AutoUpload=true, MaxFiles=4"));
        field = addUploadField(new UploadField());
        field.setMaxFiles(4);
        
       
    }
    
    protected UploadField addUploadField(UploadField field) {
       
        Bean bean = new Bean();
        Binder<Bean> binder = new Binder<>();
        
        //UploadField field = new UploadField(c.getDeclaredConstructor().newInstance());
        add(field);
        binder.forField(field).bind(Bean::getFiles, Bean::setFiles);
        
        Span message = new Span();
        add(message);
        
        Button bind = new Button("Bind",click -> {
            try {
                binder.writeBean(bean);
                message.setText("Bean Files set to: "+bean.getFiles());
            } 
            catch (ValidationException e) {
            }
        });
        add(bind);
        
        binder.readBean(bean);
        add(new Hr());
        
        return field;
        
    }
    
    public static class Bean {
        
        List<UploadFile> files;

        public Bean() {
            super();
        }

        public List<UploadFile> getFiles() {
            if(files == null) files = new ArrayList<>();
            return files;
        }

        public void setFiles(List<UploadFile> files) {
            this.files = files;
        }
    	
		
		
    	
		
    }
}

Links

• View on GitHub

Compatibility