Click here to Skip to main content
Click here to Skip to main content

Using DocxToText to Extract Text from DOCX Files

By , 17 Sep 2007
Rate this:
Please Sign up or sign in to vote.
DocxToText demo application

Introduction

At last, Microsoft has turned to XML-based format for storing document content. At the same time, it created a small problem for developers who need to index and search in Microsoft Word *.docx files. It's not a problem on a computer with Microsoft Office 2007 installed, but what is there to do if your application works on a server without Office and still needs to get text from Word files? Well, there are three options:

  • Install Microsoft Office 2007 and use its DLLs.
  • Use some third party libraries like "Office Open XML C# Library."
  • Write your own code.

In fact, there is another option: use the DocxToText class described below.

DocxToText Class

This class performs only one function: it extracts text from a given *.docx file. However, before we dig into the code, I'll remind you that a Microsoft Word *.docx file is an Open XML document combining texts, styles, graphics and so on into a single ZIP archive. Therefore we have to "unpack" the *.docx file to get to its guts. If you work with .NET Framework 3.0, you can use the Package class in the System.IO.Packaging namespace. However, working with .NET Framework 2.0, I used the open-source ZIP library SharpZipLib.

If you rename your *.docx file to *.zip and open it in your archiver, you will see a list of packed files like this:

Screenshot - screenshot2.png

First of all, we have to read the [Content_Types].xml file and find the location of the document.xml file. Usually, Microsoft hides it in the /word sub-directory, but it can be anywhere if the file was not created by Microsoft Word. Then we have to parse the document.xml file and extract text from it. A ReadNode() method does all the dirty work: it pulls out text strings, paragraphs, tabs and carriage returns, and concatenates it into final text.

Full text of the DocxToText class:

public class DocxToText
{
    private const string ContentTypeNamespace =
        @"http://schemas.openxmlformats.org/package/2006/content-types";

    private const string WordprocessingMlNamespace =
        @"http://schemas.openxmlformats.org/wordprocessingml/2006/main";

    private const string DocumentXmlXPath =
        "/t:Types/t:Override[@ContentType="" +
        "application/vnd.openxmlformats-officedocument." +
        "wordprocessingml.document.main+xml\"]";

    private const string BodyXPath = "/w:document/w:body";

    private string docxFile = "";
    private string docxFileLocation = "";

    public DocxToText(string fileName)
    {
        docxFile = fileName;
    }

    #region ExtractText()
    /// 
    /// Extracts text from the Docx file.
    /// 
    /// Extracted text.
    public string ExtractText()
    {
        if (string.IsNullOrEmpty(docxFile))
            throw new Exception("Input file not specified.");

        // Usually it is "/word/document.xml"

        docxFileLocation = FindDocumentXmlLocation();

        if (string.IsNullOrEmpty(docxFileLocation))
            throw new Exception("It is not a valid Docx file.");

        return ReadDocumentXml();
    }
    #endregion

    #region FindDocumentXmlLocation()
    /// 
    /// Gets location of the "document.xml" zip entry.
    /// 
    /// Location of the "document.xml".
    private string FindDocumentXmlLocation()
    {
        ZipFile zip = new ZipFile(docxFile);
        foreach (ZipEntry entry in zip)
        {
            // Find "[Content_Types].xml" zip entry

            if (string.Compare(entry.Name, "[Content_Types].xml", true) == 0)
            {
                Stream contentTypes = zip.GetInputStream(entry);

                XmlDocument xmlDoc = new XmlDocument();
                xmlDoc.PreserveWhitespace = true;
                xmlDoc.Load(contentTypes);
                contentTypes.Close();

                //Create an XmlNamespaceManager for resolving namespaces

                XmlNamespaceManager nsmgr = 
                    new XmlNamespaceManager(xmlDoc.NameTable);
                nsmgr.AddNamespace("t", ContentTypeNamespace);

                // Find location of "document.xml"

                XmlNode node = xmlDoc.DocumentElement.SelectSingleNode(
                    DocumentXmlXPath, nsmgr);

                if (node != null)
                {
                    string location = 
                        ((XmlElement) node).GetAttribute("PartName");
                    return location.TrimStart(new char[] {'/'});
                }
                break;
            }
        }
        zip.Close();
        return null;
    }
    #endregion

    #region ReadDocumentXml()
    /// 
    /// Reads "document.xml" zip entry.
    /// 
    /// Text containing in the document.
    private string ReadDocumentXml()
    {
        StringBuilder sb = new StringBuilder();

        ZipFile zip = new ZipFile(docxFile);
        foreach (ZipEntry entry in zip)
        {
            if (string.Compare(entry.Name, docxFileLocation, true) == 0)
            {
                Stream documentXml = zip.GetInputStream(entry);

                XmlDocument xmlDoc = new XmlDocument();
                xmlDoc.PreserveWhitespace = true;
                xmlDoc.Load(documentXml);
                documentXml.Close();

                XmlNamespaceManager nsmgr = 
                    new XmlNamespaceManager(xmlDoc.NameTable);
                nsmgr.AddNamespace("w", WordprocessingMlNamespace);

                XmlNode node = 
                    xmlDoc.DocumentElement.SelectSingleNode(BodyXPath,nsmgr);

                if (node == null)
                    return string.Empty;

                sb.Append(ReadNode(node));

                break;
            }
        }
        zip.Close();
        return sb.ToString();
    }
    #endregion

    #region ReadNode()
    /// 
    /// Reads content of the node and its nested childs.
    /// 
    /// XmlNode.
    /// Text containing in the node.
    private string ReadNode(XmlNode node)
    {
        if (node == null || node.NodeType != XmlNodeType.Element)
            return string.Empty;

        StringBuilder sb = new StringBuilder();
        foreach (XmlNode child in node.ChildNodes)
        {
            if (child.NodeType != XmlNodeType.Element) continue;

            switch (child.LocalName)
            {
                case "t":                           // Text
                    sb.Append(child.InnerText.TrimEnd());

                    string space = 
                        ((XmlElement)child).GetAttribute("xml:space");
                    if (!string.IsNullOrEmpty(space) && 
                        space == "preserve")
                        sb.Append(' ');

                    break;

                case "cr":                          // Carriage return
                case "br":                          // Page break
                    sb.Append(Environment.NewLine);
                    break;

                case "tab":                         // Tab
                    sb.Append("\t");
                    break;

                case "p":                           // Paragraph
                    sb.Append(ReadNode(child));
                    sb.Append(Environment.NewLine);
                    sb.Append(Environment.NewLine);
                    break;

                default:
                    sb.Append(ReadNode(child));
                    break;
            }
        }
        return sb.ToString();
    }
    #endregion
}

To extract text from a *.docx file using the DocxToText class, you need a few lines of code:

DocxToText dtt = new DocxToText(docxFileName);
string text = dtt.ExtractText();

Conclusion

The class is a bit primitive, but it performs its main function: to just extract text. It was quite enough to implement indexing and full-text search in *.docx files in my document storage and management system Heliocode Doc@Hand. The class does not extract page headers and footers; it does not process numbering and custom XML; similarly, it knows nothing about the data binding used in documents. If you improve the class, I'll be glad to hear about it.

History

September 17, 2007 - Initial release

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

Jevgenij lives in Riga, Latvia. He started his programmer's career in 1983 developing software for radio equipment CAD systems. Created computer graphics for TV. Developed Internet credit card processing systems for banks.
Now he is System Analyst in Accenture.
Follow on   Twitter

Comments and Discussions

 
Question.doc not readble PinmemberMember 79036395-Mar-14 20:10 
QuestionError said PinmemberJayson Ragasa2-Feb-14 11:25 
GeneralMy vote of 5 PinmemberPaul071214-May-13 4:17 
GeneralMy vote of 5 Pinmembershanawazway17-Oct-12 3:46 
QuestionError message: This is an unclosed string PinmemberHendra Bunyamin27-Jun-12 3:07 
QuestionHow can I read line numbers ? PinmemberEng Ahmadi12-Jun-12 0:24 
QuestionThis is a Keeper. Pinmembergmccoy8-Feb-12 8:38 
QuestionHow to call your class from a VB.NET project Pinmemberarrelialp12-Jan-12 1:44 
SuggestionSlightly modified Version Using Ionic.zip PinmemberMartin_Dann24-Aug-11 5:42 
QuestionHow about PDF PinmemberAndrew Polar14-Aug-11 1:35 
AnswerRe: How about PDF PinmemberJevgenij Pankov14-Aug-11 8:35 
QuestionDOCTXTOHTML Pinmemberkunal.codes9-May-11 21:11 
Questionhow to Extract image embeded in .docx document PinmemberMember 41795321-Mar-11 22:20 
AnswerRe: how to Extract image embeded in .docx document PinmemberRobert Hutch16-Feb-12 3:48 
GeneralDocx files not parsing properly PinmemberNivedita D30-Jan-11 18:27 
BugRe: Docx files not parsing properly [modified] PinmemberMember 777999828-Dec-12 5:34 
GeneralRe: Docx files not parsing properly PinmemberMember 777999828-Dec-12 16:11 
QuestionHow to Close the input file? Pinmemberkavidha28-Oct-10 20:43 
AnswerRe: How to Close the input file? PinmemberJevgenij Pankov29-Oct-10 6:57 
GeneralRe: How to Close the input file? Pinmemberkavidha31-Oct-10 15:40 
QuestionWhat should I do for huge .docx document (for ex: 100mb file) PinmemberÖzgür Çivi17-Mar-10 2:31 
GeneralGood stuff Pinmembereslsys17-Feb-10 6:06 
GeneralRe: Good stuff PinmemberEugene Pankov17-Feb-10 6:27 
Generalyou saved us a lot of work Pinmemberdmihailescu1-Dec-09 10:23 
Questionhow about word(2000-2003) document Pinmembersatyamdelhi7-Aug-09 2:21 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Mobile
Web03 | 2.8.140415.2 | Last Updated 17 Sep 2007
Article Copyright 2007 by Jevgenij Pankov
Everything else Copyright © CodeProject, 1999-2014
Terms of Use
Layout: fixed | fluid