Context Objects - Complete Guide Leave feedback

using (var converter = new Converter(
    "invoice-2024.pdf",
    (LoadContext loadContext) =>
    {
        // Access source information
        Console.WriteLine($"Loading file: {loadContext.SourceFileName}");
        Console.WriteLine($"Format: {loadContext.SourceFormat}");

        // Return appropriate load options based on format
        return new PdfLoadOptions();
    }))
{
    converter.Convert("invoice-2024.docx", new WordProcessingConvertOptions());
}

using (var converter = new Converter("quarterly-report.pdf"))
{
    converter.Convert(
        (ConvertContext convertContext) =>
        {
            // Access conversion information
            Console.WriteLine($"Converting: {convertContext.SourceFileName}");
            Console.WriteLine($"From format: {convertContext.SourceFormat}");

            // Can set cancellation token
            convertContext.CancellationToken = CancellationToken.None;

            return new WordProcessingConvertOptions();
        },
        (ConvertedContext convertedContext) =>
        {
            // Save the converted stream to file
            using (var fileStream = File.Create("quarterly-report.docx"))
            {
                convertedContext.ConvertedStream.CopyTo(fileStream);
            }
        });
}

using (var converter = new Converter("balance-sheet.pdf"))
{
    converter.Convert(
        (SaveContext saveContext) =>
        {
            // Access output information
            Console.WriteLine($"Source: {saveContext.SourceFileName}");
            Console.WriteLine($"From: {saveContext.SourceFormat}");
            Console.WriteLine($"To: {saveContext.TargetFormat}");

            // Return custom stream for output
            return File.Create("balance-sheet.xlsx");
        },
        new SpreadsheetConvertOptions());
}

using (var converter = new Converter("contract-2024.pdf"))
{
    converter.Convert(
        (SavePageContext savePageContext) =>
        {
            // Access page-specific information
            Console.WriteLine($"Processing page: {savePageContext.Page}");
            Console.WriteLine($"Source: {savePageContext.SourceFileName}");
            Console.WriteLine($"From: {savePageContext.SourceFormat}");
            Console.WriteLine($"To: {savePageContext.TargetFormat}");

            // Return stream for this specific page
            return File.Create($"contract-2024-page-{savePageContext.Page}.png");
        },
        new ImageConvertOptions());
}

using (var converter = new Converter("sales-report.pdf"))
{
    converter.Convert(
        new WordProcessingConvertOptions(),
        (ConvertedContext convertedContext) =>
        {
            // Access conversion result information
            Console.WriteLine($"Converted: {convertedContext.SourceFileName}");
            Console.WriteLine($"From: {convertedContext.SourceFormat}");
            Console.WriteLine($"To: {convertedContext.ConvertedFormat}");
            Console.WriteLine("Conversion completed!");

            // Save the converted stream to file
            using (var fileStream = File.Create("sales-report.docx"))
            {
                convertedContext.ConvertedStream.CopyTo(fileStream);
            }
        });
}

using (var converter = new Converter("monthly-report.pdf"))
{
    converter.Convert(
        new WordProcessingConvertOptions(),
        (ConvertedPageContext convertedPageContext) =>
        {
            // Access page conversion result
            Console.WriteLine($"Page {convertedPageContext.Page} converted");
            Console.WriteLine($"Format: {convertedPageContext.ConvertedFormat}");
            Console.WriteLine($"Source: {convertedPageContext.SourceFileName}");
            Console.WriteLine($"From: {convertedPageContext.SourceFormat}");

            // Save each page's stream to file
            using (var fileStream = File.Create($"monthly-report-page-{convertedPageContext.Page}.docx"))
            {
                convertedPageContext.ConvertedStream.CopyTo(fileStream);
            }
        });
}

using (var converter = new Converter("mailbox-archive.pst"))
{
    int itemCount = 0;

    converter.Convert(
        (SaveContext saveContext) =>
        {
            itemCount++;

            // Access hierarchy information for container items
            Console.WriteLine($"Item #{itemCount}");
            Console.WriteLine($"  Source: {saveContext.SourceFileName}");
            Console.WriteLine($"  Hierarchy Level: {saveContext.HierarchyLevel}");
            Console.WriteLine($"  Item Index: {saveContext.ItemIndex}");
            Console.WriteLine($"  Target Format: {saveContext.TargetFormat}");

            // Create output file with hierarchy info in name
            var outputName = $"email-L{saveContext.HierarchyLevel}-I{saveContext.ItemIndex}.pdf";
            return File.Create(outputName);
        },
        new PdfConvertOptions());

    Console.WriteLine($"Total items converted: {itemCount}");
}

// LoadContext is called for EACH document in the hierarchy
using (var converter = new Converter(
    "contract-with-attachments.pdf",
    (LoadContext loadContext) =>
    {
        // HierarchyLevel shows WHERE in the hierarchy this document is
        // Level 0 = main document
        // Level 1 = directly embedded in main document
        // Level 2 = embedded within an embedded document, etc.

        Console.WriteLine($"Loading: {loadContext.SourceFileName}");
        Console.WriteLine($"  Hierarchy Level: {loadContext.HierarchyLevel}");
        Console.WriteLine($"  Item Index: {loadContext.ItemIndex}");

        if (loadContext.HierarchyLevel == 0)
        {
            Console.WriteLine("  -> This is the main document");
        }
        else if (loadContext.HierarchyLevel == 1)
        {
            Console.WriteLine("  -> This is an embedded file in the main document");
        }
        else
        {
            Console.WriteLine($"  -> This is nested {loadContext.HierarchyLevel} levels deep");
        }

        // Return appropriate load options for the document type
        return new PdfLoadOptions();
    }))
{
    int itemCount = 0;

    converter.Convert(
        (SaveContext saveContext) =>
        {
            itemCount++;

            // SaveContext shows hierarchy level during conversion
            var outputName = $"contract-L{saveContext.HierarchyLevel}-I{saveContext.ItemIndex}.pdf";
            Console.WriteLine($"Saving: {outputName}");

            return File.Create(outputName);
        },
        new PdfConvertOptions());

    Console.WriteLine($"Total items converted: {itemCount}");
}

using (var converter = new Converter(
    "annual-report.pdf",
    (LoadContext loadContext) =>
    {
        // Choose load options based on actual file format
        if (loadContext.SourceFormat == FileType.Pdf)
            return new PdfLoadOptions { RemoveEmbeddedFiles = true };

        if (loadContext.SourceFormat == FileType.Docx)
            return new WordProcessingLoadOptions { DefaultFont = "Arial" };

        return null; // Auto-detect
    }))
{
    converter.Convert("annual-report.xlsx", new SpreadsheetConvertOptions());
}

using (var converter = new Converter("employee-handbook.pdf"))
{
    converter.Convert(
        (SavePageContext savePageContext) =>
        {
            // Create separate file for each page with custom naming
            var fileName = $"handbook-section-{savePageContext.Page:D3}.docx";
            return File.Create(fileName);
        },
        new WordProcessingConvertOptions());
}

int processedPages = 0;

using (var converter = new Converter("product-catalog.pdf"))
{
    converter.Convert(
        new ImageConvertOptions { Format = ImageFileType.Png },
        (ConvertedPageContext convertedPageContext) =>
        {
            processedPages++;
            Console.WriteLine($"Progress: Page {processedPages} of product catalog converted");

            // Save page stream
            using (var fileStream = File.Create($"catalog-page-{convertedPageContext.Page:D3}.png"))
            {
                convertedPageContext.ConvertedStream.CopyTo(fileStream);
            }
        });
}

// Old API used primitive parameters
using (var converter = new Converter("financial-statement.docx"))
{
    converter.Convert(
        (int page) => File.Create($"statement-page-{page}.pdf"),
        new PdfConvertOptions());
}

// New API uses SavePageContext with rich context information
using (var converter = new Converter("financial-statement.docx"))
{
    converter.Convert(
        (SavePageContext savePageContext) =>
        {
            // Access rich context information
            Console.WriteLine($"Converting page {savePageContext.Page} of {savePageContext.SourceFileName}");
            return File.Create($"statement-page-{savePageContext.Page}.pdf");
        },
        new PdfConvertOptions());
}