OpenXml Regex

Namespace: Clippit

Search and replace text in Word and PowerPoint documents using regular expressions, with optional revision tracking support.

public class OpenXmlRegex {
    public static int Match(IEnumerable<XElement> content, Regex regex)
    {...}

    public static int Match(
        IEnumerable<XElement> content, Regex regex, Action<XElement, Match> found)
    {...}

    public static int Replace(
        IEnumerable<XElement> content, Regex regex, string replacement,
        Func<XElement, Match, bool> doReplacement)
    {...}

    public static int Replace(
        IEnumerable<XElement> content, Regex regex, string replacement,
        Func<XElement, Match, bool> doReplacement, bool coalesceContent)
    {...}

    public static int Replace(
        IEnumerable<XElement> content, Regex regex, string replacement,
        Func<XElement, Match, bool> doReplacement,
        bool trackRevisions, string author)
    {...}
}

OpenXmlRegex works on paragraph-level content elements (Word w:p and PowerPoint a:p elements). It consolidates runs within each paragraph into a single logical string, applies the regex, and then reconstructs the runs preserving original formatting.

Key Features

• Works across runs -- text split across multiple runs is matched as a single string
• Preserves formatting -- replaced text inherits the formatting of the first matched run
• Revision tracking -- replacements in Word content can generate tracked changes with a specified author (not supported for PowerPoint)
• Callback control -- the doReplacement callback controls whether each match is replaced, enabling selective replacement (e.g., replace only the first match)

Match Sample

using var doc = WordprocessingDocument.Open("input.docx", false);
var body = doc.MainDocumentPart.GetXDocument().Root.Element(W.body);
var paragraphs = body.Descendants(W.p);

var regex = new Regex(@"\b\d{3}-\d{2}-\d{4}\b"); // SSN pattern

// Count matches
var count = OpenXmlRegex.Match(paragraphs, regex);
Console.WriteLine($"Found {count} matches");

// Inspect each match
OpenXmlRegex.Match(paragraphs, regex, (element, match) =>
{
    Console.WriteLine($"Found: {match.Value}");
});

Replace Sample

var wmlDoc = new WmlDocument("input.docx");
using var streamDoc = new OpenXmlMemoryStreamDocument(wmlDoc);
using var doc = streamDoc.GetWordprocessingDocument();
var body = doc.MainDocumentPart.GetXDocument().Root.Element(W.body);
var paragraphs = body.Descendants(W.p).ToList();

var regex = new Regex(@"PLACEHOLDER");
var replacementCount = OpenXmlRegex.Replace(
    paragraphs, regex, "Actual Value", null);
doc.MainDocumentPart.PutXDocument();

Console.WriteLine($"Replaced {replacementCount} occurrences");

Replace with Revision Tracking

var regex = new Regex(@"old text");
OpenXmlRegex.Replace(
    paragraphs,
    regex,
    "new text",
    doReplacement: null,
    trackRevisions: true,
    author: "Auto-Replace Tool"
);