iOfficeAI/OfficeCLI · error · ArgumentException

Invalid --page value '{pageFilter}': expected N or M-N or co

Error message

Invalid --page value '{pageFilter}': expected N or M-N or comma list.

What it means

ParsePptHtmlPage handles the range form 'M-N' for pptx html previews. It splits on '-' into two tokens; if either token fails int.TryParse, an ArgumentException is thrown (no Code). This is the html-mode counterpart to the SVG page parser — accepts N, M-N, and comma lists, but a non-numeric bound in a range is rejected.

Source

Thrown at src/officecli/CommandBuilder.View.cs:766

            .Resolve(formatId, OfficeCli.Core.Rendering.RenderOutputKind.Png, options.Mode);
        if (renderer == null) return null;
        return renderer.Render(
            new OfficeCli.Handlers.Rendering.HandlerRenderInput(handler, formatId), options).Bytes;
    }

    private static (int? start, int? end) ParsePptHtmlPage(
        string? pageFilter, int? start, int? end,
        OfficeCli.Handlers.PowerPointHandler pptHandler)
    {
        if (string.IsNullOrEmpty(pageFilter)) return (start, end);
        var slideCount = pptHandler.Query("slide").Count;
        var firstTok = pageFilter.Split(',')[0].Trim();
        // Range form "M-N"
        if (firstTok.Contains('-'))
        {
            var parts = firstTok.Split('-', 2);
            if (!int.TryParse(parts[0], out var ps) || !int.TryParse(parts[1], out var pe))
                throw new ArgumentException($"Invalid --page value '{pageFilter}': expected N or M-N or comma list.");
            if (ps <= 0 || pe <= 0)
                throw new ArgumentException($"Invalid --page value '{pageFilter}': slide number must be >= 1.");
            if (ps > slideCount)
                throw new ArgumentException($"--page {ps} out of range (total slides: {slideCount}).");
            return (ps, Math.Min(pe, slideCount));
        }
        if (!int.TryParse(firstTok, out var p))
            throw new ArgumentException($"Invalid --page value '{pageFilter}': expected a positive slide number.");
        if (p <= 0)
            throw new ArgumentException($"Invalid --page value '{pageFilter}': slide number must be >= 1.");
        if (p > slideCount)
            throw new ArgumentException($"--page {p} out of range (total slides: {slideCount}).");
        return (p, p);
    }
}

View on GitHub (pinned to 1ced45e900)

Solutions

  1. Use integer bounds in the range, e.g. --page 1-3
  2. For a single slide use --page 2 (no dash)
  3. For a comma list ensure every token is an integer or integer range

Example fix

// before
officecli view --mode html --page 1-end deck.pptx
// after
officecli view --mode html --page 1-3 deck.pptx
Defensive patterns

Strategy: validation

Validate before calling

// Validate a range-form --page bound for pptx html mode.
static bool IsValidPageSpec(string? pageFilter)
{
    if (string.IsNullOrEmpty(pageFilter)) return true;
    foreach (var tok in pageFilter.Split(','))
    {
        var t = tok.Trim();
        if (t.Contains('-'))
        {
            var parts = t.Split('-', 2);
            if (!int.TryParse(parts[0], out _) || !int.TryParse(parts[1], out _)) return false;
        }
        else if (!int.TryParse(t, out _)) return false;
    }
    return true;
}
if (!IsValidPageSpec(pageFilter))
{
    // reject before invoking
}

Type guard

bool IsValidPptxPageToken(string? pageFilter)
{
    if (string.IsNullOrEmpty(pageFilter)) return true;
    var firstTok = pageFilter.Split(',')[0].Trim();
    if (firstTok.Contains('-'))
    {
        var parts = firstTok.Split('-', 2);
        return int.TryParse(parts[0], out _) && int.TryParse(parts[1], out _);
    }
    return int.TryParse(firstTok, out _);
}

Try / catch

try
{
    // invoke view --mode html --page X-Y deck.pptx
}
catch (System.ArgumentException ex) when (ex.Message.Contains("expected N or M-N or comma list"))
{
    // a range bound was non-numeric; reprompt for integer bounds
}

Prevention

When it happens

Trigger: `view --mode html --page a-3 deck.pptx`, `--page 1-b`, `--page x-y`, `--page 1-` (trailing dash → empty second token). Html mode, pptx handler, range form with a non-integer bound.

Common situations: Typo in a range bound; pasting a slide-title instead of a number; a dangling dash from string concatenation; using 'last' as a bound.

Related errors

AI-assisted analysis of iOfficeAI/OfficeCLI@1ced45e900 (2026-08-13). Data as JSON: /api/errors/56a27ef75856b68d. Report an issue: GitHub.