Simulating Mail Merge with formatted HTML content by Utilizing the Find and Replace Functionality

Environment

Version	Product	Author
2025.2.520	RadWordProcessing	Desislava Yordanova

Description

This article demonstrates a sample approach how to simulate mail merge, where formatted HTML content needs to replace placeholders in a DOCX template. When performing a mail merge, the WordProcessing library binds plain HTML text, instead of rendering the HTML with its original formatting.

Solution

To successfully insert the formatted HTML content, you can use the Find-and-Replace functionality instead. Replace placeholders with the styled HTML content using the following steps:

1. Import the HTML content using HtmlFormatProvider.
2. Import the DOCX template using DocxFormatProvider.
3. Find placeholders in the template and replace them with the imported HTML content.

Code Example

// Import HTML content
RadFlowDocument htmlFlowDocument;
using (Stream input = File.OpenRead(@"info.html"))
{
    Telerik.Windows.Documents.Flow.FormatProviders.Html.HtmlFormatProvider htmlProvider = new Telerik.Windows.Documents.Flow.FormatProviders.Html.HtmlFormatProvider(); 
    htmlFlowDocument = htmlProvider.Import(input, TimeSpan.FromSeconds(10));
}

// Import DOCX template
RadFlowDocument templateFlowDocument;
Telerik.Windows.Documents.Flow.FormatProviders.Docx.DocxFormatProvider docxProvider = new Telerik.Windows.Documents.Flow.FormatProviders.Docx.DocxFormatProvider();

using (Stream input = File.OpenRead("template.docx"))
{
    templateFlowDocument = docxProvider.Import(input, TimeSpan.FromSeconds(10));
}

// Replace placeholder with HTML content
List<BlockBase> newContent = new List<BlockBase>();
RadFlowDocumentEditor editor = new RadFlowDocumentEditor(templateFlowDocument);

foreach (Section section in htmlFlowDocument.Sections)
{
    Section clonedSection = section.Clone(templateFlowDocument);
    newContent.AddRange(clonedSection.Blocks);
}

editor.ReplaceText("<<EXSUSection>>", newContent, true, false);

// Export the modified document
string outputFilePath = "output.docx";
File.Delete(outputFilePath);
using (Stream output = File.OpenWrite(outputFilePath))
{
    docxProvider.Export(templateFlowDocument, output, TimeSpan.FromSeconds(10));
}

// Open the output file
Process.Start(new ProcessStartInfo() { FileName = outputFilePath, UseShellExecute = true });

Notes:

• Replace <<EXSUSection>> with your placeholder text.
• Modify the code to suit your template and requirements.
• Ensure the provided HTML content is supported by HtmlFormatProvider.

See Also

• HtmlFormatProvider
• DocxFormatProvider
• Mail Merge Documentation
• Find-and-Replace