OpenXml and SharePoint

Question

I am developing a web-part that will generate word-documents. The word-documents are generated on the basis of a template document which has defined content controls. I want to retrieve data from SharePoint and put the data inside these content controls. Everything was working good for me when I had only one content control in my template, but after expanding the template document with more content controls I get exceptions. It seems like I am not finding the content controls. This is my method:

private void CreateReport(SPFile file)

        {
            var byteArray = file.OpenBinary();
            using (var mem = new MemoryStream())
            {
                mem.Write(byteArray, 0, byteArray.Length);
                try
                {
                    using (var wordDoc = WordprocessingDocument.Open(mem, true))
                    {
                        var mainPart = wordDoc.MainDocumentPart;

                        var firstName = mainPart.Document.Body.Descendants<SdtBlock>().Where
                            (r => r.SdtProperties.GetFirstChild<Tag>().Val == "FirstName").Single();
                        var t = firstName.Descendants<Text>().Single();
                        t.Text = _firstName;

                         var lastName = mainPart.Document.Body.Descendants<SdtBlock>().Where
                            (r => r.SdtProperties.GetFirstChild<Tag>().Val == "LastName").Single();
                         var t2= lastName.Descendants<Text>().Single();
                         t2.Text = _lastName;

                        mainPart.Document.Save();
                        SaveFileToSp(mem);
                    }

                }
                catch (FileFormatException)
                {
                }
            }
        }

This is the exception I get:

An exception of type 'System.InvalidOperationException' occurred in System.Core.dll but was not handled in user code. Innerexception: Null

Any tips for me on how I can write better method for finding controls?

Answer 1

Simplify your code and remove all the nested Linq statements at least then you can debug and see where it is going wrong.

Answer 2

Found another way to loop, and fix my problem:

private static void ReplaceTags(MainDocumentPart mainPart, string tagName, string tagValue) { //grab all the tag fields IEnumerable tagFields = mainPart.Document.Body.Descendants().Where (r => r.SdtProperties.GetFirstChild().Val == tagName);

foreach (var field in tagFields)
{
    //remove all paragraphs from the content block
    field.SdtContentBlock.RemoveAllChildren<Paragraph>();
    //create a new paragraph containing a run and a text element
    Paragraph newParagraph = new Paragraph();
    Run newRun = new Run();
    Text newText = new Text(tagValue);
    newRun.Append(newText);
    newParagraph.Append(newRun);
    //add the new paragraph to the content block
    field.SdtContentBlock.Append(newParagraph);
}

}