Prevent image merge if invalid image

Aspose.Words Product Family
1

Hi,

In our codebase, I have implemented the callback for image merging like this:

public void imageFieldMerging(ImageFieldMergingArgs ifma) throws Exception {
	try {
		// immagine richiesta
		Object field = ifma.getFieldValue();
		String path = "";

		// array di byte come path
		if (field instanceof byte[]) {
			path = new String((byte[]) field, StandardCharsets.UTF_8);
		}
		// path come stringa semplice
		else if (field != null) {
			path = field.toString();
		}

		// se
		if (
			// non è valido
			!Strings.isValid(path)
			// o non esite
			|| !Files.exists(path)
		) {
			// non proseguo
			ifma.setImage(null);
			return;
		}

		// dimensioni specificate nel documento (eventualmente non presenti)
		double width = ifma.getImageWidth().getValue();
		double height = ifma.getImageHeight().getValue();

		// se le dimensioni non sono già specificate
		if (width < 0 && height < 0) {
			DocumentBuilder builder = new DocumentBuilder(ifma.getDocument());
			builder.moveToMergeField(ifma.getDocumentFieldName(), false, false);

			// se si trova in una cella di una tabella
			Cell cell = (Cell) builder.getCurrentParagraph().getAncestor(NodeType.CELL);
			if (cell != null) {
				CellFormat format = cell.getCellFormat();

				format.setLeftPadding(0.0);
				format.setRightPadding(0.0);
				format.setTopPadding(0.0);
				format.setBottomPadding(0.0);
				format.setWrapText(false);
				format.setFitText(true);

				// uso dimensioni cella
				width = format.getWidth();
				height = cell.getParentRow().getRowFormat().getHeight();
			}

			// se si trova in un textbox
			Shape shape = (Shape) builder.getCurrentParagraph().getAncestor(NodeType.SHAPE);
			if (shape != null && shape.getShapeType() == ShapeType.TEXT_BOX) {
				TextBox tb = shape.getTextBox();

				tb.setInternalMarginBottom(0.0);
				tb.setInternalMarginTop(0.0);
				tb.setInternalMarginLeft(0.0);
				tb.setInternalMarginRight(0.0);

				// uso dimensioni textbox
				width = shape.getWidth();
				height = shape.getHeight();
			}
		}

		// se sono specificate misure massime
		if (width > 0 || height > 0) {
			// carico immagine
			BufferedImage img = ImageIO.read(new File(path));

			// ricavo fattore di scala
			int imgw = img.getWidth();
			int imgh = img.getHeight();

			// distruggo immagine
			img = null;

			// calcolo fattore di scalatura
			double scale = Math.max(imgw / width, imgh / height);

			// inserisco l'immagine specificando le dimensioni
			width = imgw / scale;
			height = imgh / scale;
		}

		// immagine come path sul disco
		ifma.setImageFileName(path);

		// imposto le dimensioni
		ifma.getImageWidth().setValue(width);
		ifma.getImageHeight().setValue(height);
	}
	// se qualcosa va male
	catch (Exception e) {
		System.err.println(Strings.getTrace(e));

		// in modalità debug
		if (Util.DEBUG) {
			// riporta errore
			throw Util.error("Errore durante il caricamento di un'immagine", e);
		}

		// setta immagine a null
		ifma.setImage(null);
	}
}

The merge is done by passing in the full path to the image file on disk, and the code should verify if the path is valid (not null and not empty), and that the image actually exists on disk; if one of the checks fail, it should “abort” the insertion.

However, it seems that setting the image as null does not work, what would the proper way be? I keep getting the exception:

Cannot load image from field 'foto'. The field contains data in unsupported format. Can't find file: /opt/agews64/data/upload/AGEWS626/5/6/5663370B-EEE4-4BDC-AFB9-C8B3BD4EE300

The file indeed does not exists, however the checks in the callback should catch this case and simply proceed without the image.

2

@mtassinari,

Thanks for your inquiry. In case you are using older version of Aspose.Words for Java, we suggest you please upgrade to the latest version of Aspose.Words for Java 17.10.

If you still face problem, please share your input Word document and simple Java application (source code without compilation errors) that helps us to reproduce your problem on our end. Please ZIP and attach these resources. We will investigate the issue and provide you more information on this.

3

We are currently testing latest 17.10 version, however I do not think it is the customer task to create a test case.

Anyway, this should be pretty simple to setup:

  • create a simple DOCX template with an image mail merge field
  • try to merge a non-existing image file with an IFieldMergingCallback that implement the imageFieldMerging with a check for file existance

I would also like to underline that my question was simply how can I stop the image merge from the callback?

The answer to that question would most certainly need no test case at all… The code above was just a reference to create some context.

4

@mtassinari,

Thanks for sharing the detail. You can simply remove the field as shown below if the image file does not exist to avoid the shared exception. Hope this helps you.

if (
    // non è valido
        !Strings.isValid(path)
                // o non esite
                || !Files.exists(path)
        ) {
    // non proseguo
    ifma.getField().remove();
    return;
}
5

It worked! Thank you!