siyuan-note/siyuan · error

empty result

Error message

empty result

What it means

`markdownToBlockDOM` ran the input through `luteEngine.Md2BlockDOMTree` and the resulting block DOM string was empty, meaning Lute produced no blocks. SiYuan cannot insert a block from empty DOM, so it surfaces this error rather than writing nothing.

Source

Thrown at kernel/mcp/tools/block.go:406

	}
	return CallToolResult{Content: []ContentItem{{Type: "text", Text: "block deleted: " + id}}}, nil
}

func getBlockData(args map[string]any) (data, dataType string) {
	data, _ = args["data"].(string)
	dataType, _ = args["dataType"].(string)
	if dataType == "" {
		dataType = "markdown"
	}
	return
}

func markdownToBlockDOM(md string) (string, error) {
	luteEngine := util.NewLute()
	luteEngine.SetHTMLTag2TextMark(true)
	result, _ := luteEngine.Md2BlockDOMTree(md, true)
	if result == "" {
		return "", fmt.Errorf("empty result")
	}
	return result, nil
}

func blockMove(args map[string]any) (CallToolResult, error) {
	id, _ := args["id"].(string)
	if id == "" {
		return CallToolResult{Content: []ContentItem{{Type: "text", Text: "id is required"}}, IsError: true}, nil
	}
	parentID, _ := args["parentID"].(string)
	if parentID == "" {
		return CallToolResult{Content: []ContentItem{{Type: "text", Text: "parentID is required"}}, IsError: true}, nil
	}
	previousID, _ := args["previousID"].(string)
	boxID, release, scopeErr := beginBlockToolScope(args, true, id, parentID, previousID)
	if scopeErr != nil {
		return blockToolError(scopeErr.Error())
	}

View on GitHub (pinned to 251596fc0d)

Solutions

1. Provide non-empty markdown that contains at least one renderable block (a heading, paragraph, list item, etc.).
2. Strip pure-metadata constructs (front matter, lone link definitions) before sending if they are the only content.
3. Validate the input on the caller side: reject empty/whitespace-only `markdown` before invoking the tool.

Example fix

// before
{"markdown": ""}
// after
{"markdown": "# Hello world"}

// Reject empty/whitespace markdown before calling create-block.
if strings.TrimSpace(markdown) == "" {
    return errors.New("markdown must contain at least one renderable block")
}

When it happens

Trigger: Passing markdown that yields no block — an empty string, only whitespace, only front-matter/comment syntax that Lute discards, or content consisting entirely of elements Lute strips (e.g. raw HTML comments, lone link definitions).

Common situations: Calling `create-block`-style tools with `markdown: ""` or `markdown: " "`. Sending a snippet that is only a YAML front-matter block or only reference-style link definitions, which do not become visible blocks.

Related errors

• invalid tool arguments: %w
• name must end in .html or .htm
• encrypted notebook is locked, please unlock it first
• path is required
• path escapes templates dir: %s

AI-assisted analysis of siyuan-note/siyuan@251596fc0d (2026-08-12). Data as JSON: /api/errors/c665d11095eac5ab. Report an issue: GitHub.