Have you ever wondered how would you show on a web form text that is stripped of HTML tags but you still want to accept HTML tags when saving to your form? Sounds confusing?
To make it clear, I will give a good example. Lets say you have a form that has a Rich Text Box (FTB or FCK) which you allow users to cut and paste items that have HTML tags so that you can display it properly like a Blog Article, but there are some instances that you want this to be stripped of the HTML tags like displaying a summary on a Grid. Now my solution is to strip the HTML codes before displaying it when needed.
So when you copy this
Hello, World!
it wont show on your grid as this
<html> <head> <title> Hello World </title> </head> <body> <font size ="4" color="blue"> Hello, World! </font> </body> </html>
but as this
"Hello World!"
Now with a mix or Replace and Regular Expressions I created a class to handle that and here it is:
public string StripHTML(string sInputString)
{
try
{
string sOutputString;
sOutputString = sInputString;
//Initial Cleaning Step
//Replace new line and carriage return with Spaces
sOutputString = sOutputString.Replace("r", " ");
sOutputString = sOutputString.Replace("n", " ");
// Remove sTabs
sOutputString = sOutputString.Replace("t", string.Empty);
//Tag Removal
DataTable myDataTable = GetTableDefinition();
myDataTable.DefaultView.Sort = "iID ASC";
foreach (DataRow drCleaningItem in myDataTable.Rows)
{
string sOriginalString = (drCleaningItem["sOriginalString"]).ToString();
string sReplacementString = (drCleaningItem["sReplacementString"]).ToString();
sOutputString = Regex.Replace(sOutputString, sOriginalString, sReplacementString, RegexOptions.IgnoreCase);
}
//Initial replacement target string for linebreaks
string sBreaks = "rrr";
// Initial replacement target string for sTabs
string sTabs = "ttttt";
for (int x = 0; x < sOutputString.Length; x++)
{
sOutputString = sOutputString.Replace(sBreaks, "rr");
sOutputString = sOutputString.Replace(sTabs, "tttt");
sBreaks = sBreaks + "r";
sTabs = sTabs + "t";
}
return sOutputString;
}
catch
{
return sInputString;
}
}
private DataTable GetTableDefinition()
{
DataTable dtCleaningCollection = new DataTable();
dtCleaningCollection.Columns.Add("iID", typeof(int));
dtCleaningCollection.Columns.Add("sOriginalString", typeof(string));
dtCleaningCollection.Columns.Add("sReplacementString", typeof(string));
// Replace repeating spaces with single space
dtCleaningCollection.Rows.Add(1, @"( )+", " ");
// Prepare and clean Header Tag
dtCleaningCollection.Rows.Add(2, @"<( )*head([^>])*>", "<head>");
dtCleaningCollection.Rows.Add(3, @"(<( )*(/)( )*head( )*>)", "</head>");
dtCleaningCollection.Rows.Add(4, "(<head>).*(</head>)", string.Empty);
// Prepare and clean Script Tag
dtCleaningCollection.Rows.Add(5, @"<( )*script([^>])*>", "<script>");
dtCleaningCollection.Rows.Add(6, @"(<( )*(/)( )*script( )*>)", "</script>");
dtCleaningCollection.Rows.Add(7, @"(<script>).*(</script>)", string.Empty);
// Prepare and clean Style Tag
dtCleaningCollection.Rows.Add(8, @"<( )*style([^>])*>", "<style>");
dtCleaningCollection.Rows.Add(9, @"(<( )*(/)( )*style( )*>)", "</style>");
dtCleaningCollection.Rows.Add(10, "(<style>).*(</style>)", string.Empty);
// Replace <td> with sTabs
dtCleaningCollection.Rows.Add(11, @"<( )*td([^>])*>", "t");
// Replace <BR> and <LI> with Line sBreaks
dtCleaningCollection.Rows.Add(12, @"<( )*br( )*>", "r");
dtCleaningCollection.Rows.Add(13, @"<( )*li( )*>", "r");
// Replace <P>, <DIV> and <TR> with Double Line sBreaks
dtCleaningCollection.Rows.Add(14, @"<( )*div([^>])*>", "rr");
dtCleaningCollection.Rows.Add(15, @"<( )*tr([^>])*>", "rr");
dtCleaningCollection.Rows.Add(16, @"<( )*p([^>])*>", "rr");
// Remove Remaining tags enclosed in < >
dtCleaningCollection.Rows.Add(17, @"<[^>]*>", string.Empty);
// Replace special characters:
dtCleaningCollection.Rows.Add(18, @" ", " ");
dtCleaningCollection.Rows.Add(19, @"•", " * ");
dtCleaningCollection.Rows.Add(20, @"‹", "<");
dtCleaningCollection.Rows.Add(21, @"›", ">");
dtCleaningCollection.Rows.Add(22, @"™", "(tm)");
dtCleaningCollection.Rows.Add(23, @"⁄", "/");
dtCleaningCollection.Rows.Add(24, @"<", "<");
dtCleaningCollection.Rows.Add(25, @">", ">");
dtCleaningCollection.Rows.Add(26, @"©", "(c)");
dtCleaningCollection.Rows.Add(27, @"®", "(r)");
dtCleaningCollection.Rows.Add(28, @"¼", "1/4");
dtCleaningCollection.Rows.Add(29, @"½", "1/2");
dtCleaningCollection.Rows.Add(30, @"¾", "3/4");
dtCleaningCollection.Rows.Add(31, @"‘", "'");
dtCleaningCollection.Rows.Add(32, @"’", "'");
dtCleaningCollection.Rows.Add(33, @"“", """);
dtCleaningCollection.Rows.Add(34, @"”", """);
// Remove all others remianing special characters
// you dont want to replace with another string
dtCleaningCollection.Rows.Add(35, @"&(.{2,6});", string.Empty);
// Remove extra line sBreaks and sTabs
dtCleaningCollection.Rows.Add(36, "(r)( )+(r)", "rr");
dtCleaningCollection.Rows.Add(37, "(t)( )+(t)", "tt");
dtCleaningCollection.Rows.Add(38, "(t)( )+(r)", "tr");
dtCleaningCollection.Rows.Add(39, "(r)( )+(t)", "rt");
dtCleaningCollection.Rows.Add(40, "(r)(t)+(r)", "rr");
dtCleaningCollection.Rows.Add(41, "(r)(t)+", "rt");
return dtCleaningCollection;
}