iOfficeAI/OfficeCLI · error · ArgumentException

source must not be empty

Error message

source must not be empty

What it means

RefreshPivotCacheFromSource requires a non-empty source range spec; passing null, empty, or all-whitespace is rejected before any parsing happens. The helper cannot infer a default range, and silently no-op-ing would leave the user thinking the refresh succeeded. The check is the first guard in the method.

Source

Thrown at src/officecli/Core/PivotTableHelper.Readback.cs:372

            if (axisAsDataFieldNames.Count > 0)
                node.Format["axisAsDataField"] = string.Join(",", axisAsDataFieldNames);
        }
    }

    /// <summary>
    /// R10-1: refresh a pivot's cache definition + records from a new source
    /// range spec ("Sheet1!A1:C4" or "A1:C4" — same sheet as the existing
    /// CacheSource). Replaces CacheFields, updates WorksheetSource.Reference
    /// (and Sheet if changed), rewrites the PivotTableCacheRecordsPart, and
    /// resizes pivotDef.PivotFields to match the new column count. Existing
    /// PivotField Axis/DataField assignments are reset because indices may no
    /// longer line up — RebuildFieldAreas reapplies them after this returns.
    /// </summary>
    private static void RefreshPivotCacheFromSource(PivotTablePart pivotPart, string newSourceSpec,
        Dictionary<string, string>? pendingFieldAreaProps = null)
    {
        if (string.IsNullOrWhiteSpace(newSourceSpec))
            throw new ArgumentException("source must not be empty");
        newSourceSpec = newSourceSpec.Trim();
        if (newSourceSpec.StartsWith("["))
            throw new ArgumentException(
                "External workbook references are not supported in pivot source. "
                + "Use a local sheet name (e.g. Sheet1!A1:D10)");

        var cachePart = pivotPart.GetPartsOfType<PivotTableCacheDefinitionPart>().FirstOrDefault()
            ?? throw new InvalidOperationException("Pivot table has no cache definition part");
        var cacheDef = cachePart.PivotCacheDefinition
            ?? throw new InvalidOperationException("Pivot cache definition is missing");
        var existingWsSource = cacheDef.CacheSource?.WorksheetSource
            ?? throw new InvalidOperationException("Pivot cache source is not a worksheet source");

        // Parse the new source spec.
        string newSheetName;
        string newRef;
        if (newSourceSpec.Contains('!'))
        {

View on GitHub (pinned to 1ced45e900)

Solutions

1. Provide a concrete range spec: source=Sheet1!A1:D100 or source=A1:D100 (same sheet as the existing cache source)
2. Validate the input is non-empty in your own layer before calling refresh
3. If you do not want to refresh the source, omit the source= property entirely instead of passing empty

Example fix

// before
source=""
// after
source="Sheet1!A1:D100"

if (string.IsNullOrWhiteSpace(sourceSpec))
    throw new InvalidOperationException("Pivot source spec is required for refresh");

static bool IsValidSourceSpec(string? s) => !string.IsNullOrWhiteSpace(s);

try { RefreshPivotCacheFromSource(pivotPart, sourceSpec); }
catch (ArgumentException ex) when (ex.Message == "source must not be empty")
{ /* prompt user for a source range */ }

When it happens

Trigger: source= with no value; source=" " (whitespace); source passed from an unset config variable; a UI that submitted the form with the source field empty.

Common situations: Missing required input; programmatic call that forgot to populate the source argument; template/render path that omits source when it should always be present for a refresh.

Related errors

• calculatedField requires a non-empty name
• calculatedField '{name}' requires a non-empty formula
• calculatedField '{raw}' must be 'Name:=Formula' (colon-separ
• field '{name}' not found in source headers: {available}
• External workbook references are not supported in pivot sour

AI-assisted analysis of iOfficeAI/OfficeCLI@1ced45e900 (2026-08-13). Data as JSON: /api/errors/b46386224947d932. Report an issue: GitHub.