91 lines
3.7 KiB
C#
91 lines
3.7 KiB
C#
namespace ASC.Common.Utils;
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public static class HtmlUtil
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{
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private static readonly Regex _tagReplacer
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= new Regex("<[^>]*>", RegexOptions.Multiline | RegexOptions.Compiled);
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private static readonly Regex _commentsReplacer
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= new Regex("<!--(?s).*?-->", RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.Compiled);
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private static readonly Regex _xssReplacer
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= new Regex(@"<\s*(style|script)[^>]*>(.*?)<\s*/\s*(style|script)>", RegexOptions.IgnoreCase
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| RegexOptions.CultureInvariant | RegexOptions.Compiled | RegexOptions.Singleline);
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private static readonly Regex _worder =
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new Regex(@"\S+", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
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public static string GetText(string html, int maxLength = 0, string endBlockTemplate = "...")
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{
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var unformatedText = string.Empty;
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if (!string.IsNullOrEmpty(html))
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{
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html = _xssReplacer.Replace(html, string.Empty); //Clean malicious tags. <script> <style>
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if (string.IsNullOrEmpty(html))
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{
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return html;
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}
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unformatedText = _tagReplacer.Replace(html, string.Empty);
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if (!string.IsNullOrEmpty(unformatedText))
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{
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// kill comments
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unformatedText = _commentsReplacer.Replace(unformatedText, string.Empty);
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unformatedText = unformatedText.Trim();
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if (!string.IsNullOrEmpty(unformatedText))
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{
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if (maxLength == 0 || unformatedText.Length < maxLength)
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{
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return HttpUtility.HtmlDecode(unformatedText);
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}
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//Set maximum length with end block
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maxLength = Math.Max(0, maxLength - endBlockTemplate.Length);
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var startIndex = Math.Max(0, Math.Min(unformatedText.Length - 1, maxLength));
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var countToScan = Math.Max(0, startIndex - 1);
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var lastSpaceIndex = unformatedText.LastIndexOf(' ', startIndex, countToScan);
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unformatedText = lastSpaceIndex > 0 && lastSpaceIndex < unformatedText.Length
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? unformatedText.Remove(lastSpaceIndex)
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: unformatedText.Substring(0, maxLength);
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if (!string.IsNullOrEmpty(endBlockTemplate))
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{
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unformatedText += endBlockTemplate;
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}
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}
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}
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}
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return HttpUtility.HtmlDecode(unformatedText);//TODO:!!!
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}
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public static string ToPlainText(string html)
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{
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return GetText(html);
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}
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/// <summary>
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/// The function highlight all words in htmlText by searchText.
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/// </summary>
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/// <param name="searchText">the space separated string</param>
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/// <param name="htmlText">html for highlight</param>
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/// <param name="withoutLink"></param>
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/// <returns>highlighted html</returns>
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public static string SearchTextHighlight(string searchText, string htmlText, bool withoutLink = false)
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{
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if (string.IsNullOrEmpty(searchText) || string.IsNullOrEmpty(htmlText))
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{
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return htmlText;
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}
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var regexpstr = _worder.Matches(searchText).Select(m => m.Value).Distinct().Aggregate((r, n) => r + "|" + n);
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var wordsFinder = new Regex(Regex.Escape(regexpstr), RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.CultureInvariant | RegexOptions.Multiline);
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return wordsFinder.Replace(htmlText, m => "<span class='searchTextHighlight" + (withoutLink ? " bold" : string.Empty) + "'>" + m.Value + "</span>");
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}
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} |