Export Rich Text to plain text c# - excel

Question

Good day to Stackoverflow community,
I am in need of some expert assistance. I have an MVC4 web app that has a few rich text box fields powered by TinyMCE. Up until now the system is working great. Last week my client informed me that they want to export the data stored in Microsoft SQL to Excel to run custom reports.
I am able to export the data to excel with the code supplied. However it is exporting the data in RTF rather than Plain text. This is causing issues when they try to read the content.
Due to lack of knowledge and or understanding I am unable to figure this out. I did read that it is possible to use regex to do this however I have no idea how to implement this. So I turn to you for assistance.
public ActionResult ExportReferralData()
{
GridView gv = new GridView();
gv.DataSource = db.Referrals.ToList();
gv.DataBind();
Response.ClearContent();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment; filename=UnderwritingReferrals.xls");
Response.ContentType = "application/ms-excel";
Response.AddHeader("Content-Type", "application/vnd.ms-excel");
Response.Charset = "";
Response.Cache.SetCacheability(HttpCacheability.NoCache);
StringWriter sw = new StringWriter();
HtmlTextWriter htw = new HtmlTextWriter(sw);
gv.RenderControl(htw);
Response.Output.Write(sw.ToString());
Response.Flush();
Response.End();
return RedirectToAction("Index");
}
I would really appreciate any assistance. and thank you in advance.
I have looked for solutions on YouTube and web forums with out any success.
Kind Regards
Francois Muller

Answer 1

One option you can perform is to massage the Data you write to the XML file.
For example, idenfity in your string and replace it with string.Empty.
Similarly can be replaced with string.Empty.
Once you have identified all the variants of the Rich Text HTML tags, you can just create a list of the Tags, and inside a for FOR loop replace each of them with a suitable string.

Answer 2

Did you try saving the file as .xslx and sending over to the client.
The newer Excel format might handle the data more gracefully?

Answer 3

Add this function to your code, and then you can invoke the function passing it in the HTML string. The return output will be HTML free.
Warning: This does not work for all cases and should not be used to process untrusted user input. Please test it with variants of your input string.
public static string StripTagsCharArray(string source)
{
char[] array = new char[source.Length];
int arrayIndex = 0;
bool inside = false;
for (int i = 0; i < source.Length; i++)
{
char let = source[i];
if (let == '<')
{ inside = true; continue; }
if (let == '>') { inside = false; continue; }
if (!inside) { array[arrayIndex] = let; arrayIndex++; }
}
return new string(array, 0, arrayIndex);
}

Answer 4

So I managed to resolve this issue by changing the original code as follow:
As I'm only trying to convert a few columns, I found this to be working well. This will ensure each records is separated by row in Excel and converts the Html to plain text allowing users to add column filters in Excel.
I hope this helps any one else that has a similar issue.
GridView gv = new GridView();
var From = RExportFrom;
var To = RExportTo;
if (RExportFrom == null || RExportTo == null)
{
/* The actual code to be used */
gv.DataSource = db.Referrals.OrderBy(m =>m.Date_Logged).ToList();
}
else
{
gv.DataSource = db.Referrals.Where(m => m.Date_Logged >= From && m.Date_Logged <= To).OrderBy(m => m.Date_Logged).ToList();
}
gv.DataBind();
foreach (GridViewRow row in gv.Rows)
{
if (row.Cells[20].Text.Contains("<"))
{
row.Cells[20].Text = Regex.Replace(row.Cells[20].Text, "<(?<tag>.+?)(>|>)", " ");
}
if (row.Cells[21].Text.Contains("<"))
{
row.Cells[21].Text = Regex.Replace(row.Cells[21].Text, "<(?<tag>.+?)(>|>)", " ");
}
if (row.Cells[22].Text.Contains("<"))
{
row.Cells[22].Text = Regex.Replace(row.Cells[22].Text, "<(?<tag>.+?)(>|>)", " ");
}
if (row.Cells[37].Text.Contains("<"))
{
row.Cells[37].Text = Regex.Replace(row.Cells[37].Text, "<(?<tag>.+?)(>|>)", " ");
}
if (row.Cells[50].Text.Contains("<"))
{
row.Cells[50].Text = Regex.Replace(row.Cells[37].Text, "<(?<tag>.+?)(>|>)", " ");
}
}
Response.ClearContent();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment; filename=Referrals " + DateTime.Now.ToString("dd/MM/yyyy") + ".xls");
Response.ContentType = "application/ms-excel";
Response.ContentEncoding = System.Text.Encoding.UTF8;
Response.AddHeader("Content-Type", "application/vnd.ms-excel");
Response.Charset = "";
Response.Cache.SetCacheability(HttpCacheability.NoCache);
StringWriter sw = new StringWriter();
HtmlTextWriter htw = new HtmlTextWriter(sw);
gv.RenderControl(htw);
//This code will export the data to Excel and remove all HTML Tags to pass everything into Plain text.
//I am using HttpUtility.HtmlDecode twice as the first instance changes null values to "Â" the second time it will run the replace code.
//I am using Regex.Replace to change the headings to more understandable headings rather than the headings produced by the Model.
Response.Write(HttpUtility.HtmlDecode(sw.ToString())
.Replace("Cover_Details", "Referral Detail")
.Replace("Id", "Identity Number")
.Replace("Unique_Ref", "Reference Number")
.Replace("Date_Logged", "Date Logged")
.Replace("Logged_By", "File Number")
.Replace("Date_Referral", "Date of Referral")
.Replace("Referred_By", "Name of Referrer")
.Replace("UWRules", "Underwriting Rules")
.Replace("Referred_To", "Name of Referrer")
);
Response.Flush();
Response.End();
TempData["success"] = "Data successfully exported!";
return RedirectToAction("Index");
}