Kareadita/Kavita · warning · KavitaException

Image element does not have a valid source attribute

Error message

Image element does not have a valid source attribute

What it means

Thrown by BookService.CopyImageToTempFromBook (line 1268) when the selected <img>/<image> node has neither a 'src' attribute nor an 'xlink:href' attribute (the only two src attribute names GetImageSrcAttributeName recognizes). The image element exists but Kavita cannot determine its source.

Source

Thrown at Kavita.Services/BookService.cs:1268

            if (images == null || images.Count == 0)
            {
                throw new KavitaException("No images found on the specified page");
            }

            if (bookmarkDto.ImageOffset >= images.Count)
            {
                throw new KavitaException($"Image index {bookmarkDto.ImageOffset} is out of range. Page has {images.Count} images");
            }

            var targetImage = images[bookmarkDto.ImageOffset];

            // Get the image source attribute
            var srcAttributeName = GetImageSrcAttributeName(targetImage);

            if (string.IsNullOrEmpty(srcAttributeName))
            {
                throw new KavitaException("Image element does not have a valid source attribute");
            }

            var imageSource = targetImage.Attributes[srcAttributeName].Value;

            // Clean and get the correct key for the image
            var imageKey = CleanContentKeys(GetKeyForImage(book, imageSource));

            // Check if it's an external URL
            if (imageKey.StartsWith("http"))
            {
                throw new KavitaException("Cannot copy external images");
            }

            // Get the image file from the epub

            if (!book.Content.Images.TryGetLocalFileRefByKey(imageKey, out var imageFile))
            {
                throw new KavitaException($"Image file not found in epub: {imageKey}");

View on GitHub (pinned to 9c3e540000)

Solutions

  1. Repair the epub so image elements use standard src (or xlink:href for SVG image).
  2. Extend GetImageSrcAttributeName to recognize additional common attributes (data-src) if appropriate for your corpus.

Example fix

// before
private static string? GetImageSrcAttributeName(HtmlNode targetImage) {
    if (targetImage.Attributes["src"] != null) return "src";
    if (targetImage.Attributes["xlink:href"] != null) return "xlink:href";
    return null;
}

// after — also accept lazy-load variants
if (targetImage.Attributes["data-src"] != null) return "data-src";
Defensive patterns

Strategy: validation

Validate before calling

// Pre-check the image element's source attribute on the client
const hasSrc = img.hasAttribute('src') || img.hasAttribute('xlink:href');
if (!hasSrc) { /* don't offer copy-image for this element */ }

Prevention

When it happens

Trigger: An epub page whose image element uses a non-standard attribute (e.g. data-src, poster) or a malformed/empty image tag with no src/xlink:href.

Common situations: Hand-authored or converter-produced epub with lazy-loading 'data-src' attributes; SVG <image> missing xlink:href.

Related errors

AI-assisted analysis of Kareadita/Kavita@9c3e540000 (2026-08-13). Data as JSON: /api/errors/9a8f7ff156213453. Report an issue: GitHub.