PdfExtractionService.cs

Service that extracts text content from PDF files using UglyToad.PdfPig.

What it does

Provides PDF text extraction functionality:

1. Opens PDF files from file path or stream
2. Iterates through all pages
3. Extracts text content from each page
4. Returns combined text with page break markers

Interface

public interface IPdfExtractionService
{
    PdfExtractionResult ExtractFromFile(string filePath);
    PdfExtractionResult ExtractFromStream(Stream stream);
}

Result class

public class PdfExtractionResult
{
    public string RawText { get; set; }    // Combined text from all pages
    public int PageCount { get; set; }      // Number of pages in PDF
    public string? Error { get; set; }      // Error message if extraction failed
}

Key concepts

UglyToad.PdfPig

A .NET library for reading and extracting content from PDF files. It provides:

• Cross-platform PDF parsing
• Text extraction with positioning information
• No external dependencies

Error handling

The service wraps all operations in try-catch to provide graceful error handling:

• Returns error message in result instead of throwing
• Allows caller to check Error property for failures

Usage

public class MyController : ControllerBase
{
    private readonly IPdfExtractionService _pdfService;

    public MyController(IPdfExtractionService pdfService)
    {
        _pdfService = pdfService;
    }

    public IActionResult ExtractPdf(string path)
    {
        var result = _pdfService.ExtractFromFile(path);

        if (!string.IsNullOrEmpty(result.Error))
            return BadRequest(result.Error);

        return Ok(result.RawText);
    }
}

Registration

Registered via UpDocComposer as a scoped service.