C# Finding relevant document snippets for search result display

Question

In developing search for a site I am building, I decided to go the cheap and quick way and use Microsoft Sql Server\'s Full Text Search engine instead of something more robust l

Answer 1

I took another approach, perhaps it will help someone...

First it searches if it word appears in my case with IgnoreCase (you change this of course yourself). Then I create a list of Regex matches on each separators and search for the first occurrence of the word (allowing partial case insensitive matches). From that index, I get the 10 matches in front and behind the word, which makes the snippet.

public static string GetSnippet(string text, string word)
{
    if (text.IndexOf(word, StringComparison.InvariantCultureIgnoreCase) == -1)
    {
        return "";
    }

    var matches = new Regex(@"\b(\S+)\s?", RegexOptions.Singleline | RegexOptions.Compiled).Matches(text);

    var p = -1;
    for (var i = 0; i < matches.Count; i++)
    {
        if (matches[i].Value.IndexOf(word, StringComparison.InvariantCultureIgnoreCase) != -1)
        {
            p = i;
            break;
        }
    }

    if (p == -1) return "";
    var snippet = "";
    for (var x = Math.Max(p - 10, 0); x < p + 10; x++)
    {
        snippet += matches[x].Value + " ";
    }
    return snippet;
}