siyuan-note/siyuan · error

unsupported attribute view rich text style

Error message

unsupported attribute view rich text style

What it means

As part of rich-text tree validation, every node's style IAL attribute is run through normalizeValueTextRichStyle, which whitelists the CSS style properties allowed in attribute-view rich text. If a style string cannot be normalized to the sanctioned form, the walk stops with this error (a fixed-message error variable, declared at kernel/av/value.go:1281). The unrelated "USED AT app/electron/main.js" references only show an Electron catch block capturing kernel errors, not this error's origin.

Source

Thrown at kernel/av/value.go:1281

	}
	match := valueTextRichBuiltinStylePattern.FindStringSubmatch(value)
	if 5 != len(match) || match[1] != match[3] || match[2] != valueSuffix || match[4] != legacySuffix {
		return "", false
	}
	return fmt.Sprintf("var(--b3-inline-builtin-%s-%s, var(--b3-card-%s-%s))",
		match[1], valueSuffix, match[1], legacySuffix), true
}

func normalizeValueTextRichTreeStyles(tree *parse.Tree) (err error) {
	ast.Walk(tree.Root, func(node *ast.Node, entering bool) ast.WalkStatus {
		if !entering || ast.NodeTextMark != node.Type || 1 > len(node.KramdownIAL) {
			return ast.WalkContinue
		}
		style := node.IALAttr("style")
		var normalized string
		var ok bool
		if normalized, ok = normalizeValueTextRichStyle(style); !ok {
			err = fmt.Errorf("unsupported attribute view rich text style")
			return ast.WalkStop
		}
		node.SetIALAttr("style", normalized)
		node.Next.Tokens = parse.IAL2Tokens(node.KramdownIAL)
		return ast.WalkContinue
	})
	return
}

func isAllowedValueTextRichBlockIAL(node *ast.Node) bool {
	ial := parse.Tokens2IAL(node.Tokens)
	if 1 > len(ial) {
		return false
	}
	hasID := false
	for _, attr := range ial {
		if 2 != len(attr) {
			return false

View on GitHub (pinned to 8641553a1f)

Solutions

  1. Strip the offending style attribute from the span/block in the cell content and re-apply only supported styles via the UI
  2. Paste as plain text or use SiYuan's own style toolbar so only whitelisted style IALs are generated
  3. Run the content through NormalizeValueTextRich so styles are normalized where possible before validation
  4. Restore the cell from a snapshot if the styles came from corrupted third-party writes

Example fix

// before
content = "<span style=\"background:url(x);color:red\">t</span>"
// after
content = "<span style=\"color: var(--b3-font-color1)\">t</span>" // whitelisted style only
Defensive patterns

Strategy: validation

Validate before calling

if _, ok := av.NormalizeStyleForCheck(styleAttr); !ok { styleAttr = "" } // drop disallowed styles early

Try / catch

if err != nil && strings.Contains(err.Error(), "unsupported attribute view rich text style") {
    // strip style IALs and re-apply via the editor
}

Prevention

When it happens

Trigger: Rich-text content whose spans/blocks carry style attributes with disallowed or malformed CSS (e.g. url() payloads, unknown properties, broken declarations). Reached through validateValueTextRichTree during ParseValueTextRich / NormalizeValueTextRich / RenderValueTextRich.

Common situations: Content pasted from external rich-text editors that injects arbitrary inline styles (font, position, background-url); hand-edited kramdown with custom style="..." IALs; data written by older or third-party tooling.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

AI-assisted analysis of siyuan-note/siyuan@8641553a1f (2026-09-11). Data as JSON: /api/errors/8bf9493a23d185d1. Report an issue: GitHub.