/// <summary>
/// Filters text to only allow defined HTML.
/// </summary>
/// <param name="allowedHtmlTags">The allowed html tags.</param>
/// <param name="text">Text.</param>
/// <returns></returns>
public static string ConvertToAllowedHtml(NameValueCollection allowedHtmlTags, string text)
{
if (allowedHtmlTags == null || allowedHtmlTags.Count == 0)
{
//This indicates that the AllowableCommentHtml configuration is either missing or
//has no values, therefore just strip the text as normal.
return(HtmlSafe(text));
}
var regex = new HtmlTagRegex();
MatchCollection matches = regex.Matches(text);
if (matches.Count == 0)
{
return(HtmlSafe(text));
}
var sb = new StringBuilder();
int currentIndex = 0;
foreach (Match match in matches)
{
//Append text before the match.
if (currentIndex < match.Index)
{
sb.Append(HtmlSafe(text.Substring(currentIndex, match.Index - currentIndex)));
}
string tagName = match.Groups["tagname"].Value.ToLower(CultureInfo.InvariantCulture);
//check each match against the list of allowable tags.
if (allowedHtmlTags.Get(tagName) == null)
{
sb.Append(HtmlSafe(match.Value));
}
else
{
bool isEndTag = match.Groups["endTag"].Value.Length > 0;
if (isEndTag)
{
sb.AppendFormat("</{0}>", tagName);
}
else
{
sb.Append("<" + tagName);
sb.Append(FilterAttributes(tagName, match, allowedHtmlTags) + ">");
}
}
currentIndex = match.Index + match.Length;
}
//add the remaining text.
if (currentIndex < text.Length)
{
sb.Append(HtmlSafe(text.Substring(currentIndex)));
}
var converter = new XhtmlConverter();
return(converter.Transform(sb.ToString()));
}
public void Transform_WithValidMarkup_DoesNotChangeIt(string markup, string expected)
{
//arrange
var converter = new XhtmlConverter();
//act
string result = converter.Transform(markup);
//assert
Assert.AreEqual(expected, result);
}
public void ConvertHtmlToXhtmlEnsuresSomeTagsMustNotBeSelfClosed(string html, string expected, string message)
{
//arrange
var converter = new XhtmlConverter();
//act
string result = converter.Transform(html);
//assert
Assert.AreEqual(expected, result);
}
public void ConvertHtmlToXHtmlCorrectsInvalidMarkup(string badMarkup, string corrected)
{
//arrange
var converter = new XhtmlConverter();
//act
string result = converter.Transform(badMarkup);
//assert
Assert.AreEqual(corrected, result);
}
public void ConvertHtmlToXHtmlLeavesNestedMarkupAlone()
{
//arrange
const string expected = "<p><span>This is some text</span> <span>this is more text</span></p>";
var converter = new XhtmlConverter();
//act
string result = converter.Transform(expected);
//assert
Assert.AreEqual(expected, result);
}
public void ConvertHtmlToXhtmlEnsuresSomeTagsMustBeSelfClosed(string tag)
{
//arrange
string html = string.Format(CultureInfo.InvariantCulture, "<{0} src=\"blah-blah\"></{0}>", tag);
string expected = string.Format(CultureInfo.InvariantCulture, "<{0} src=\"blah-blah\" />", tag);
var converter = new XhtmlConverter();
//act
string result = converter.Transform(html);
//assert
Assert.AreEqual(expected, result);
}
public void Transform_WithConverter_AppliesConverterWhileConvertingHtml()
{
const string html = "<p title=\"blah blah\"> blah blah </p>";
const string expected = "<p title=\"blah blah\"> yadda yadda </p>";
//arrange
var converter = new XhtmlConverter(input => input.Replace("blah", "yadda"));
//act
string result = converter.Transform(html);
//assert
Assert.AreEqual(expected, result);
}
public void Transform_WithStyleTag_DoesNotWrapStyleInCdata()
{
const string html = "<style>.test {color: blue;}</style>";
const string expected = html;
//arrange
var converter = new XhtmlConverter();
//act
string result = converter.Transform(html);
//assert
Assert.AreEqual(expected, result);
}
public void Transform_WithAngleBracketInAttributeValue_EncodesAttribute()
{
const string html = @"<a title="">"">b</a>";
const string expected = @"<a title="">"">b</a>";
//arrange
var converter = new XhtmlConverter();
//act
string result = converter.Transform(html);
//assert
Assert.AreEqual(expected, result);
}
/// <summary>
/// Wraps an anchor tag around all urls. Makes sure not to wrap already
/// wrapped urls.
/// </summary>
/// <param name="html">Html containing urls to convert.</param>
/// <returns></returns>
public static string ConvertUrlsToHyperLinks(string html)
{
if (html == null)
{
throw new ArgumentNullException("html");
}
if (html.Length == 0)
{
return(string.Empty);
}
var xhtmlConverter = new XhtmlConverter(text =>
{
const string pattern = @"((https?|ftp)://|www\.)[\w]+(.[\w]+)([\w\-\.,@?^=%&:/~\+#]*[\w\-\@?^=%&/~\+#])";
MatchCollection matches =
Regex.Matches(text, pattern,
RegexOptions.
IgnoreCase |
RegexOptions.Compiled);
foreach (Match m in matches)
{
string httpPortion = string.Empty;
if (!m.Value.Contains("://"))
{
httpPortion = "http://";
}
text =
text.Replace(m.Value,
string.Format(CultureInfo.InvariantCulture,
"<a rel=\"nofollow external\" href=\"{0}{1}\" title=\"{1}\">{2}</a>",
httpPortion, m.Value, ShortenUrl(m.Value, 50))
);
}
return(text);
});
return(xhtmlConverter.Transform(html));
}
