I am trying to use the iTextSharp Library to read PDF files. The example code from devTo is as following:
var reader = new PdfReader(File.ReadAllBytes(#"..\..\..\sample.pdf"));
for (var pageNum = 1; pageNum <= reader.NumberOfPages; pageNum++)
{
// Get the page content and tokenize it.
var contentBytes = reader.GetPageContent(pageNum);
var tokenizer = new PrTokeniser(new RandomAccessFileOrArray(contentBytes))
var stringsList = new List<string>();
while (tokenizer.NextToken())
{
if (tokenizer.TokenType == PrTokeniser.TK_STRING)
{
// Extract string tokens.
stringsList.Add(tokenizer.StringValue);
}
}
// Print the set of string tokens, one on each line.
Console.WriteLine(string.Join("\r\n", stringsList));
}
reader.Close();
But this code just makes every found test in a new line feed. I need to get every block found in the PDF as a sentence or sentences. Any other block should be in new Line feed.
In the header of the PDFs I am testing, there is three columns (receiver of bill at left, information of organization at the middle and information of the sender at the right side). After that begins the body of the PDF.
How can I catch that in code? Does anyone have meet this problem before? I really appreciate any help!
Related
I have an existing library that I can use to receive a docx file and return it. The software is .Net Core hosted in a Linux Docker container.
It's very limited in scope though and I need to perform some actions it can't do. As these are straightforward I thought I would use OpenXML, and for my proof of concept all I need to do is to read a docx as a memorystream, replace some text, turn it back into a memorystream and return it.
However the docx that gets returned is unreadable. I've commented out the text replacement below to eliminate that, and if I comment out the call to the method below then the docx can be read so I'm sure the issue is in this method.
Presumably I'm doing something fundamentally wrong here but after a few hours googling and playing around with the code I am not sure how to correct this; any ideas what I have wrong?
Thanks for the help
private MemoryStream SearchAndReplace(MemoryStream mem)
{
mem.Position = 0;
using (WordprocessingDocument wordDoc = WordprocessingDocument.Open(mem, true))
{
string docText = null;
StreamReader sr = new StreamReader(wordDoc.MainDocumentPart.GetStream());
docText = sr.ReadToEnd();
//Regex regexText = new Regex("Hello world!");
//docText = regexText.Replace(docText, "Hi Everyone!");
MemoryStream newMem = new MemoryStream();
newMem.Position = 0;
StreamWriter sw = new StreamWriter(newMem);
sw.Write(docText);
return newMem;
}
}
If your real requirement is to search and replace text in a WordprocessingDocument, you should have a look at this answer.
The following unit test shows how you can make your approach work if the use case really demands that you read a string from a part, "massage" the string, and write the changed string back to the part. It also shows one of the shortcomings of any other approach than the one described in the answer already mentioned above, e.g., by demonstrating that the string "Hello world!" will not be found in this way if it is split across w:r elements.
[Fact]
public void CanSearchAndReplaceStringInOpenXmlPartAlthoughThisIsNotTheWayToSearchAndReplaceText()
{
// Arrange.
using var docxStream = new MemoryStream();
using (var wordDocument = WordprocessingDocument.Create(docxStream, WordprocessingDocumentType.Document))
{
MainDocumentPart part = wordDocument.AddMainDocumentPart();
var p1 = new Paragraph(
new Run(
new Text("Hello world!")));
var p2 = new Paragraph(
new Run(
new Text("Hello ") { Space = SpaceProcessingModeValues.Preserve }),
new Run(
new Text("world!")));
part.Document = new Document(new Body(p1, p2));
Assert.Equal("Hello world!", p1.InnerText);
Assert.Equal("Hello world!", p2.InnerText);
}
// Act.
SearchAndReplace(docxStream);
// Assert.
using (WordprocessingDocument wordDocument = WordprocessingDocument.Open(docxStream, false))
{
MainDocumentPart part = wordDocument.MainDocumentPart;
Paragraph p1 = part.Document.Descendants<Paragraph>().First();
Paragraph p2 = part.Document.Descendants<Paragraph>().Last();
Assert.Equal("Hi Everyone!", p1.InnerText);
Assert.Equal("Hello world!", p2.InnerText);
}
}
private static void SearchAndReplace(MemoryStream docxStream)
{
using (WordprocessingDocument wordDocument = WordprocessingDocument.Open(docxStream, true))
{
// If you wanted to read the part's contents as text, this is how you
// would do it.
string partText = ReadPartText(wordDocument.MainDocumentPart);
// Note that this is not the way in which you should search and replace
// text in Open XML documents. The text might be split across multiple
// w:r elements, so you would not find the text in that case.
var regex = new Regex("Hello world!");
partText = regex.Replace(partText, "Hi Everyone!");
// If you wanted to write changed text back to the part, this is how
// you would do it.
WritePartText(wordDocument.MainDocumentPart, partText);
}
docxStream.Seek(0, SeekOrigin.Begin);
}
private static string ReadPartText(OpenXmlPart part)
{
using Stream partStream = part.GetStream(FileMode.OpenOrCreate, FileAccess.Read);
using var sr = new StreamReader(partStream);
return sr.ReadToEnd();
}
private static void WritePartText(OpenXmlPart part, string text)
{
using Stream partStream = part.GetStream(FileMode.Create, FileAccess.Write);
using var sw = new StreamWriter(partStream);
sw.Write(text);
}
Currently I am using a custom LocationTextExtractionStrategy to extract text from a PDF that returns a TextRenderInfo[]. I would like to be able to determine if a TextRenderInfo object (or PDFString, child of TextRenderInfo) appears in a specific layer. I am not sure if this is possible. To get the layers in a PDF, I am using:
Dictionary<string,PdfLayer> layers;
using (var pdfReader = new PdfReader(src))
{
var newSrc = Path.Combine(["new file location"]);
using (var stream = new FileStream(newSrc, FileMode.Create))
{
PdfStamper stamper = new PdfStamper(pdfReader, stream);
layers = stamper.GetPdfLayers();
stamper.Close();
}
pdfReader.Close();
src = newSrc;
}
To extract the text, I am using:
var textExtractor = new TextExtractionStrategy();
PdfTextExtractor.GetTextFromPage(pdfReader, pdfPageNum,textExtractor);
List<TextRenderInfo> results = textExtractor.Results;
Is there any way that I can check if the individual TextRenderInfo results exist within the layers obtained in the first code snippet. Any help would be much appreciated.
It is possible to get the contents from a single layer, but you'll have to jump through a few hoops to work it out. Specifically, you will have to recreate some of the logic that is provided by the PdfTextExtractor and PdfReaderContentParser.
public static String GetText(PdfReader reader, int pageNumber, int streamNumber) {
var strategy = new LocationTextExtractionStrategy();
var processor = new PdfContentStreamProcessor(strategy);
var resourcesDic = pageDic.GetAsDict(PdfName.RESOURCES);
// assuming you still need to extract the page bytes
byte[] contents = GetContentBytesForPageStream(reader, pageNumber, streamNumber);
processor.ProcessContent(contents, resourcesDic);
return strategy.GetResultantText();
}
public static byte[] GetContentBytesForPageStream(PdfReader reader, int pageNumber, int streamNumber) {
PdfDictionary pageDictionary = reader.GetPageN(pageNum);
PdfObject contentObject = pageDictionary.Get(PdfName.CONTENTS);
if (contentObject == null)
return new byte[0];
byte[] contentBytes = GetContentBytesFromContentObject(contentObject, streamNumber);
return contentBytes;
}
public static byte[] GetContentBytesFromContentObject(PdfObject contentObject, int streamNumber) {
// copy-paste logic from
// ContentByteUtils.GetContentBytesFromContentObject(contentObject);
// but in case PdfObject.ARRAY: only select the streamNumber you require
}
If you're specifically looking to just use PdfTextExtractor or PdfReaderContentParser, and ask the returned TextRenderInfo for the layer it's on, then I'm not sure it will be easily possible. There are a number of problems with that:
TextRenderInfo doesn't store that information, so you'd have to subclass it (which is possible)
you'd have to rewrite the logic that creates the TextRenderInfo objects. This is possible by registering custom IContentOperator objects for all text operators (Tj, TJ, ' and ") with the PdfTextExtractor or PdfReaderContentParser
the hardest part is that you have already lost layer information in ContentByteUtils.GetContentBytesFromContentObject - so you'd need to retain that somehow, which creates its own set of problems.
Please help me understand if my solution is correct.
I'm trying to extract text from a PDF file with a LocationTextExtractionStrategy parser. I'm getting exceptions because the ParseContentMethod tries to parse inline images? The code is simple and looks similar to this:
RenderFilter[] filter = { new RegionTextRenderFilter(cropBox) };
ITextExtractionStrategy strategy = new FilteredTextRenderListener(new LocationTextExtractionStrategy(), filter);
PdfTextExtractor.GetTextFromPage(pdfReader, pageNumber, strategy);
I realize the images are in the content stream but I have a PDF file failing to extract text because of inline images. It returns an UnsupportedPdfException of "The filter /DCTDECODE is not supported" and then it finally fails with and InlineImageParseException of "Could not find image data or EI", when all I really care about is the text. The BI/EI exists in my file so I assume this failure is because of the /DCTDECODE exception. But again, I don't care about images, I'm looking for text.
My current solution for this is to add a filterHandler in the InlineImageUtils class that assigns the Filter_DoNothing() filter to the DCTDECODE filterHandler dictionary. This way I don't get exceptions when I have InlineImages with DCTDECODE. Like this:
private static bool InlineImageStreamBytesAreComplete(byte[] samples, PdfDictionary imageDictionary) {
try {
IDictionary<PdfName, FilterHandlers.IFilterHandler> handlers = new Dictionary<PdfName, FilterHandlers.IFilterHandler>(FilterHandlers.GetDefaultFilterHandlers());
handlers[PdfName.DCTDECODE] = new Filter_DoNothing();
PdfReader.DecodeBytes(samples, imageDictionary, handlers);
return true;
} catch (IOException e) {
return false;
}
}
public class Filter_DoNothing : FilterHandlers.IFilterHandler
{
public byte[] Decode(byte[] b, PdfName filterName, PdfObject decodeParams, PdfDictionary streamDictionary)
{
return b;
}
}
My problem with this "fix" is that I had to change the iTextSharp library. I'd rather not do that so I can try to stay compatible with future versions.
Here's the PDF in question:
https://app.box.com/s/7eaewzu4mnby9ogpl2frzjswgqxn9rz5
I am getting a pdf-document (no password) which is generated from a third party software with javascript and a few editable fields in it. If I load this pdf-document with the pdfReader class the NumberOfPagesProperty is always 1 although the pdf-document has 17 pages. Oddly enough the document has 17 pages if I save the stream afterwards. When I now try to open the document the Acrobat Reader shows an extended feature warning and the fields are not fillable anymore (I haven't flattened the document). Do anyone know about such a problem?
Background Info:
My job is to remove the javascript code, fill out some fields and save the document afterwards.
I am using the iTextsharp version 5.5.3.0.
Unfortunately I can't upload a sample file because there are some confidental data in it.
private byte[] GetDocumentData(string documentName)
{
var document = String.Format("{0}{1}\\{2}.pdf", _component.OutputDirectory, _component.OutputFileName.Replace(".xml", ".pdf"), documentName);
if (File.Exists(document))
{
PdfReader.unethicalreading = true;
using (var originalData = new MemoryStream(File.ReadAllBytes(document)))
{
using (var updatedData = new MemoryStream())
{
var pdfTool = new PdfInserter(originalData, updatedData) {FormFlattening = false};
pdfTool.RemoveJavascript();
pdfTool.Save();
return updatedData.ToArray();
}
}
}
return null;
}
//Old version that wasn't working
public PdfInserter(Stream pdfInputStream, Stream pdfOutputStream)
{
_pdfInputStream = pdfInputStream;
_pdfOutputStream = pdfOutputStream;
_pdfReader = new PdfReader(_pdfInputStream);
_pdfStamper = new PdfStamper(_pdfReader, _pdfOutputStream);
}
//Solution
public PdfInserter(Stream pdfInputStream, Stream pdfOutputStream, char pdfVersion = '\0', bool append = true)
{
_pdfInputStream = pdfInputStream;
_pdfOutputStream = pdfOutputStream;
_pdfReader = new PdfReader(_pdfInputStream);
_pdfStamper = new PdfStamper(_pdfReader, _pdfOutputStream, pdfVersion, append);
}
public void RemoveJavascript()
{
for (int i = 0; i <= _pdfReader.XrefSize; i++)
{
PdfDictionary dictionary = _pdfReader.GetPdfObject(i) as PdfDictionary;
if (dictionary != null)
{
dictionary.Remove(PdfName.AA);
dictionary.Remove(PdfName.JS);
dictionary.Remove(PdfName.JAVASCRIPT);
}
}
}
The extended feature warning is a hint that the original PDF had been signed using a usage rights signature to "Reader-enable" it, i.e. to tell the Adobe Reader to activate some additional features when opening it, and the OP's operation on it has invalidated the signature.
Indeed, he operated using
_pdfStamper = new PdfStamper(_pdfReader, _pdfOutputStream);
which creates a PdfStamper which completely re-generates the document. To not invalidate the signature, though, one has to use append mode as in the OP's fixed code (for char pdfVersion = '\0', bool append = true):
_pdfStamper = new PdfStamper(_pdfReader, _pdfOutputStream, pdfVersion, append);
If I load this pdf-document with the pdfReader class the NumberOfPagesProperty is always 1 although the pdf-document has 17 pages. Oddly enough the document has 17 pages
Quite likely it is a PDF with a XFA form, i.e. the PDF is only a carrier of some XFA data from which Adobe Reader builds those 17 pages. The actual PDF in that case usually only contains one page saying something like "if you see this, your viewer does not support XFA."
For a final verdict, though, one has to inspect the PDF.
I have a W9 PDF document that I am filling with data for just a single record per button click. Now the client would like to create a single document where each record is a page in the document. Below is our code to create a PDF for each employee.
protected void lnkFillFields_Click(object sender, EventArgs e)
{
using (Library.Data.PDFData data = new Library.Data.PDFData())
{
try
{
Document document = new Document();
PdfCopy writer = new PdfCopy(document, Response.OutputStream);
document.Open();
foreach (EmployeeData emp in data.sp_select_employee_data())
{
//Creates a PDF from a byte array
PdfReader reader =
new PdfReader((Byte[])data.sp_select_doc(16).Tables[0].Rows[0]["doc"]);
//Creates a "stamper" object used to populate interactive fields
MemoryStream ms = new MemoryStream();
PdfStamper stamper = new PdfStamper(reader, ms);
try
{
//MUST HAVE HERE BEFORE STREAMING!!!
//This line populates the interactive fields with your data.
// false = Keeps the fields as editable
// true = Turns all of the editable fields to their read-only equivalent
stamper.FormFlattening = false;
//fill in PDF here
stamper.Close();
reader.Close();
MergePDFs(writer, ms);
}
catch (Exception ex)
{
throw ex;
}
}
document.Close();
//Stream the file to the user
Response.ContentType = "application/pdf";
Response.BufferOutput = true;
Response.AppendHeader("Content-Disposition", "attachment; filename=W9"+ "_Complete.pdf");
Response.Flush();
Response.End();
}
catch (Exception ex)
{
throw ex;
}
}
}
Inserting a page wasn't the way to go. Instead, merging the documents was essentially what we wanted. Therefore, we have come up with this method:
UPDATE
Below is the method that we came up with that successfully stitches a new PDF to the previous one.
private static void MergePDFs(PdfCopy writer, MemoryStream ms)
{
PdfReader populated_reader = new PdfReader(ms.ToArray());
//Add this pdf to the combined writer
int n = populated_reader.NumberOfPages;
for (int i = 1; i <= n; i++)
{
PdfImportedPage page = writer.GetImportedPage(populated_reader, i);
writer.AddPage(page);
}
}
What we need to do is create all of this in memory, then spit it out to the user for download.
Check out kuujinbo's tutorial here for combining/stitching PDFs together.
Before you do that, you'll also need to obviously generate the PDFs, too. You might be tempted to try to do it all in one pass which will work but will be harder to debug. Instead, I'd recommend making two passes, the first to create the individual documents and the second to combine them. Your first pass can temporarily writer them to either disk or memory. Your code (and kuujinbo's) actually writes directly to the Response stream which is completely valid, too, but also much harder to debug, especially if you wrap everything in a giant try/catch.
The number of PDFs you're joining and the frequency of generation should determine where you're temporarily storing the first pass two. If you're only doing up to a dozen or two and they're not giant I would persist to a MemoryStream and work with the .ToArray() byte data on that.
If you've got more PDFs than that or they're fairly large or this routine gets called often or you have RAM constraints you might be better persisting them to a unique folder first, stitching them and then deleting that folder.