stefanuebe / vaadin-lazy-download-button Goto Github PK

If createInputStream fails, it's not possible to intercept the exception and handle it.
Moreover, if setDisableOnClick is set, the button will remain disabled (because no DownloadStartsEvent will occur).

As a workaround, one need to write error handling logic inside of the InputStreamFactory:

btnDownload = new LazyDownloadButton("Download",
	() -> "foo.pdf",
	() -> {
		try {
			return new ByteArrayInputStream(generateFile());
		} catch (RuntimeException e) {
			btnDownload.getUI().ifPresent(ui->ui.access(()->{
				// restore normal state, so that the user can download the content again
				btnDownload.setText("Download");
				btnDownload.setEnabled(true);
				Notification.show("Download failed").addThemeVariants(NotificationVariant.LUMO_ERROR);
			}));
			throw e;
		}
	});

Hello.

Download button working super great when you set filename callback and inputstream callback and constructor.

But when i set filename and inputstream callback after the button was created, the download does not occur.

Example:

 private final LazyDownloadButton downloadButton = new LazyDownloadButton(VaadinIcon.FILE_ZIP.create());

 downloadButton.setFileNameCallback(() -> filename);
 downloadButton.setInputStreamCallback(() -> new ByteArrayInputStream(byte array content));

Reason: looks like the constructor with only ICON does not add click listener for downloading

Update2 ():
1)

   private LazyDownloadButton downloadButton = new LazyDownloadButton(VaadinIcon.FILE_ZIP.create(), null, null);

 downloadButton.setFileNameCallback(() -> filename);
 downloadButton.setInputStreamCallback(() -> new ByteArrayInputStream(byte array content));

Error:

java.lang.NullPointerException: File name callback must not be null
	at java.util.Objects.requireNonNull(Objects.java:233) ~[?:?]
	at org.vaadin.stefan.LazyDownloadButton.lambda$null$3(LazyDownloadButton.java:100) ~[lazy-download-button-1.0.0.jar:1.0.0]

Vaadin 23.2.3, 23.1.10
Java 17

Hi Stefan,

Is this component still being maintained? I cannot get either the demo at https://stefan.app.fi/lazy-download-button-demo/ to work (only the eager button works) and the integration in my application also does not work. Sometimes there is after some minutes a browser download popup saying there was an error downloading but thats it.

Thx for checking.