What causes "attribute view source is required" in siyuan-note/siyuan?

Read the current AV data and pass those bytes as `original` before calling SaveAttributeViewIfUnchanged

attribute view source is required

Error message

attribute view source is required

What it means

SaveAttributeViewIfUnchanged performs a compare-and-swap style save: it only writes if the global database still matches the `original` bytes captured by the caller. Passing nil for `original` means there is no baseline to compare against, so the API refuses the call — callers wanting unconditional saves must use SaveAttributeView instead.

Solutions

Read the current AV data and pass those bytes as `original` before calling SaveAttributeViewIfUnchanged
If an unconditional save is intended, call SaveAttributeView(av) instead
Restructure the flow so the conditional-save path is only reached when a real snapshot was captured

Example fix

// before
av.SaveAttributeViewIfUnchanged(attrView, nil)
// after
original, err := av.GetAttributeViewData(av.ID)
if err != nil { return err }
err = av.SaveAttributeViewIfUnchanged(attrView, original)

Defensive patterns

Strategy: validation

Validate before calling

if original == nil {
  return errors.New("SaveAttributeViewIfUnchanged requires a non-nil original snapshot; use SaveAttributeView for unconditional saves")
}

Try / catch

if err := avlib.SaveAttributeViewIfUnchanged(attrView, original); err != nil {
  if strings.Contains(err.Error(), "source is required") {
    return avlib.SaveAttributeView(attrView) // fall back to unconditional
  }
  return err
}

Prevention

Always capture the current AV data bytes before scheduling a conditional save
Use SaveAttributeView when no baseline exists (e.g. first creation)
Keep snapshot capture and conditional save in the same code path so nil cannot slip through

When it happens

Trigger: Calling SaveAttributeViewIfUnchanged(av, nil); a code path that conditionally captured the original bytes (e.g. only when the file existed) and then proceeds to the conditional save even when capture failed; refactor that swapped SaveAttributeView for SaveAttributeViewIfUnchanged without threading the original snapshot.

Common situations: Plugin/automation code doing optimistic concurrency saves that skipped the initial read; first-creation flows where no original data exists; merge scripts that pass through a nil baseline.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of siyuan-note/siyuan@9f775e8a12 (2026-09-19). Data as JSON: /api/errors/dced3b3bf7166bdb. Report an issue: GitHub.

Appendix: source

Thrown at kernel/av/av.go:950

		}
	}
	if nil == err {
		err = CheckSpec(ret)
	}
	if nil == err {
		err = ret.NormalizeRichText()
	}
	return
}

func SaveAttributeView(av *AttributeView) (err error) {
	return saveAttributeView(av, nil)
}

// SaveAttributeViewIfUnchanged 仅在全局数据库仍与扫描源一致时原子保存。
func SaveAttributeViewIfUnchanged(av *AttributeView, original []byte) error {
	if original == nil {
		return errors.New("attribute view source is required")
	}
	return saveAttributeView(av, original)
}

func saveAttributeView(av *AttributeView, original []byte) (err error) {
	if !ast.IsNodeIDPattern(av.ID) {
		err = ErrInvalidAttributeViewID
		logging.LogErrorf("save attribute view failed: %s", err)
		return
	}
	defer func() {
		if nil == err {
			av.ResetCardCoverPositionChanges()
		}
	}()

	if err = av.NormalizeRichText(); nil != err {
		logging.LogErrorf("normalize attribute view [%s] rich text failed: %s", av.ID, err)

View on GitHub (pinned to 9f775e8a12)