Aspose Calling UpdateFields() on document loses mail merge field data

Question

I am trying to export a Word document (link to a sample file which is not working as expected is given below) to PDF using Aspose. https://1drv.ms/w/s!AheHNqR6oXmSmd5H80L0vzCTfVVrTg

The code for the same is as below.

var doc=new Document(<streamFromTheFile>); // Aspose.Words.Document
doc.UpdateFields();// This is required for any possible formula
var outStream=new MemoryStream();
doc.Save(outStream, SaveFormat.Pdf); // Aspose.Words.SaveFormat
File.WriteAllBytes(<exportPdfFilePath>, outStream.ToArray());

Every other files work fine except the ones which has a merge field as in the sample document where even the current value is lost and is replaced by the merge field name like «AtpIssueDate». Taking away the UpdateFields() method call fixes the issue but it cannot be done because it breaks the very logic. Please help how to keep the values of merged fields without removing the UpdateFields() call on export.

score 2 · Accepted Answer · answered Oct 28 '18 at 13:14

You can workaround this problem by using the following code:

Document doc = new Document("D:\\temp\\so.docx");

// LOCK merge fields before Updatefields method call
foreach(Field field in doc.Range.Fields)
{
    if (field.Type == FieldType.FieldMergeField)
    {
        field.IsLocked = true;
    }
}

doc.UpdateFields();

// UN-LOCK merge fields after Updatefields method call
foreach (Field field in doc.Range.Fields)
{
    if (field.Type == FieldType.FieldMergeField)
    {
        field.IsLocked = false;
    }
}

doc.Save("D:\\temp\\18.10.pdf");

Hope, this helps. I work with Aspose as Developer Evangelist.

❤ Way to go. That worked :) Great job, Awaiz. Thank you very much — Ananthan Unni, Oct 29 '18 at 11:35

score 1 · Answer 2 · edited Oct 29 '18 at 09:12

Sounds like you need to traversal your document specifically.

I wrote the next code to reproduce and resolve you problem. You can customize this for you needs. You can just get field type like in this example FieldType Enumeration

using System.IO;
using System.Linq;
using Aspose.Words;
using Aspose.Words.Fields;

namespace ConsoleApplication1
{
  public class Program
  {
    public static void Main()
    {
      Stream file = new FileStream("SO.docx", FileMode.Open);
      var doc = new Document(file);

      var nodes = doc.GetChildNodes(NodeType.Any, true);

      foreach (var node in nodes)
      {
        if (node.NodeType != NodeType.Paragraph)
          continue;
        if (!(node is Paragraph paragraph))
          continue;

        if (paragraph.ChildNodes.Any(x => x.NodeType == NodeType.FieldStart))
        {
          var childNodes = paragraph.ChildNodes;
          var isParagraphContainsMergedField = childNodes.Any(x => (x as FieldChar)?.FieldType == FieldType.FieldMergeField);
          if (isParagraphContainsMergedField)
            continue;
        }

        node.Range.UpdateFields();
      }

      var outStream = new MemoryStream();
      doc.Save(outStream, SaveFormat.Pdf);
      File.WriteAllBytes("test.pdf", outStream.ToArray());
    }
  }
}

Hopefully it helps.

P.S.: don't forget use using or dispose your streams.

Thanks for the reply. But this is kind of brings up some overhead. — Ananthan Unni, Oct 29 '18 at 11:34
@AnanthanUnni, yep, Awais Hafeez solution is more accurate and simple. — Anton Komyshan, Oct 29 '18 at 12:38

Aspose Calling UpdateFields() on document loses mail merge field data

2 Answers2