asternet/docs/SearchHelp.aspx
2016-10-03 11:15:07 +02:00

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<%@ Page Language="C#" EnableViewState="False" %>
<script runat="server">
//===============================================================================================================
// System : Sandcastle Help File Builder
// File : SearchHelp.aspx
// Author : Eric Woodruff (Eric@EWoodruff.us)
// Updated : 05/15/2014
// Note : Copyright 2007-2015, Eric Woodruff, All rights reserved
// Compiler: Microsoft C#
//
// This file contains the code used to search for keywords within the help topics using the full-text index
// files created by the help file builder.
//
// This code is published under the Microsoft Public License (Ms-PL). A copy of the license should be
// distributed with the code. It can also be found at the project website: http://SHFB.CodePlex.com. This
// notice, the author's name, and all copyright notices must remain intact in all applications, documentation,
// and source files.
//
// Date Who Comments
// ==============================================================================================================
// 06/24/2007 EFW Created the code
// 02/17/2012 EFW Switched to JSON serialization to support websites that use something other than ASP.NET
// such as PHP.
// 05/15/2014 EFW Updated for use with the lightweight website presentation styles
//===============================================================================================================
/// <summary>
/// This class is used to track the results and their rankings
/// </summary>
private class Ranking
{
public string Filename, PageTitle;
public int Rank;
public Ranking(string file, string title, int rank)
{
Filename = file;
PageTitle = title;
Rank = rank;
}
}
/// <summary>
/// Render the search results
/// </summary>
/// <param name="writer">The writer to which the results are written</param>
protected override void Render(HtmlTextWriter writer)
{
JavaScriptSerializer jss = new JavaScriptSerializer();
string searchText, ftiFile;
char letter;
bool sortByTitle = false;
jss.MaxJsonLength = Int32.MaxValue;
// The keywords for which to search should be passed in the query string
searchText = this.Request.QueryString["Keywords"];
if(String.IsNullOrEmpty(searchText))
{
writer.Write("<strong>Nothing found</strong>");
return;
}
// An optional SortByTitle option can also be specified
if(this.Request.QueryString["SortByTitle"] != null)
sortByTitle = Convert.ToBoolean(this.Request.QueryString["SortByTitle"]);
List<string> keywords = this.ParseKeywords(searchText);
List<char> letters = new List<char>();
List<string> fileList;
Dictionary<string, List<long>> ftiWords, wordDictionary = new Dictionary<string,List<long>>();
// Load the file index
using(StreamReader sr = new StreamReader(Server.MapPath("fti/FTI_Files.json")))
{
fileList = jss.Deserialize<List<string>>(sr.ReadToEnd());
}
// Load the required word index files
foreach(string word in keywords)
{
letter = word[0];
if(!letters.Contains(letter))
{
letters.Add(letter);
ftiFile = Server.MapPath(String.Format(CultureInfo.InvariantCulture, "fti/FTI_{0}.json", (int)letter));
if(File.Exists(ftiFile))
{
using(StreamReader sr = new StreamReader(ftiFile))
{
ftiWords = jss.Deserialize<Dictionary<string, List<long>>>(sr.ReadToEnd());
}
foreach(string ftiWord in ftiWords.Keys)
wordDictionary.Add(ftiWord, ftiWords[ftiWord]);
}
}
}
// Perform the search and return the results as a block of HTML
writer.Write(this.Search(keywords, fileList, wordDictionary, sortByTitle));
}
/// <summary>
/// Split the search text up into keywords
/// </summary>
/// <param name="keywords">The keywords to parse</param>
/// <returns>A list containing the words for which to search</returns>
private List<string> ParseKeywords(string keywords)
{
List<string> keywordList = new List<string>();
string checkWord;
string[] words = Regex.Split(keywords, @"\W+");
foreach(string word in words)
{
checkWord = word.ToLower(CultureInfo.InvariantCulture);
if(checkWord.Length > 2 && !Char.IsDigit(checkWord[0]) && !keywordList.Contains(checkWord))
keywordList.Add(checkWord);
}
return keywordList;
}
/// <summary>
/// Search for the specified keywords and return the results as a block of HTML
/// </summary>
/// <param name="keywords">The keywords for which to search</param>
/// <param name="fileInfo">The file list</param>
/// <param name="wordDictionary">The dictionary used to find the words</param>
/// <param name="sortByTitle">True to sort by title, false to sort by ranking</param>
/// <returns>A block of HTML representing the search results</returns>
private string Search(List<string> keywords, List<string> fileInfo,
Dictionary<string, List<long>> wordDictionary, bool sortByTitle)
{
StringBuilder sb = new StringBuilder(10240);
Dictionary<string, List<long>> matches = new Dictionary<string, List<long>>();
List<long> occurrences;
List<int> matchingFileIndices = new List<int>(), occurrenceIndices = new List<int>();
List<Ranking> rankings = new List<Ranking>();
string filename, title;
string[] fileIndex;
bool isFirst = true;
int idx, wordCount, matchCount;
foreach(string word in keywords)
{
if(!wordDictionary.TryGetValue(word, out occurrences))
return "<strong>Nothing found</strong>";
matches.Add(word, occurrences);
occurrenceIndices.Clear();
// Get a list of the file indices for this match
foreach(long entry in occurrences)
occurrenceIndices.Add((int)(entry >> 16));
if(isFirst)
{
isFirst = false;
matchingFileIndices.AddRange(occurrenceIndices);
}
else
{
// After the first match, remove files that do not appear for
// all found keywords.
for(idx = 0; idx < matchingFileIndices.Count; idx++)
if(!occurrenceIndices.Contains(matchingFileIndices[idx]))
{
matchingFileIndices.RemoveAt(idx);
idx--;
}
}
}
if(matchingFileIndices.Count == 0)
return "<strong>Nothing found</strong>";
// Rank the files based on the number of times the words occurs
foreach(int index in matchingFileIndices)
{
// Split out the title, filename, and word count
fileIndex = fileInfo[index].Split('\x0');
title = fileIndex[0];
filename = fileIndex[1];
wordCount = Convert.ToInt32(fileIndex[2]);
matchCount = 0;
foreach(string word in keywords)
{
occurrences = matches[word];
foreach(long entry in occurrences)
if((int)(entry >> 16) == index)
matchCount += (int)(entry & 0xFFFF);
}
rankings.Add(new Ranking(filename, title, matchCount * 1000 / wordCount));
if(rankings.Count > 99)
break;
}
// Sort by rank in descending order or by page title in ascending order
rankings.Sort(delegate (Ranking x, Ranking y)
{
if(!sortByTitle)
return y.Rank - x.Rank;
return x.PageTitle.CompareTo(y.PageTitle);
});
// Format the file list and return the results
sb.Append("<ol>");
foreach(Ranking r in rankings)
sb.AppendFormat("<li><a href=\"{0}\" \" target=\"_blank\">{1}</a></li>", r.Filename, r.PageTitle);
sb.Append("</ol>");
if(rankings.Count < matchingFileIndices.Count)
sb.AppendFormat("<p>Omitted {0} more results</p>", matchingFileIndices.Count - rankings.Count);
return sb.ToString();
}
</script>