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 files = List.of(new UploadFile(new FileData("serverfile.txt","txt",new ByteArrayOutputStream()),null)); field.setValue(files); ```