/// <summary>
/// Compare 2 integer
/// </summary>
/// <param name="a">distance a</param>
/// <param name="b">distance b</param>
/// <returns></returns>
private static int CompareByDistance(MobileResource a, MobileResource b)
{
if (a.Distance < b.Distance)
{
return(-1);
}
else if (a.Distance < b.Distance)
{
return(1);
}
else
{
return(0);
}
}
/// <summary>
/// Create and filter the suggestion link in a list
/// </summary>
/// <param name="intendedPage"></param>
private void MakeSuggestions(string intendedPage)
{
//Set it to desire likeness of words using Levenshtein Distance Algorithm
//.60 to .70 is the suggested distance, default is .60
double showPageNotFoundDistance = AppLogic.AppConfigNativeDouble("404.ComparisonDistance");
// Default value is 5
int numberOfSuggestedLinks = AppLogic.AppConfigNativeInt("404.NumberOfSuggestedLinks");
intendedPage = intendedPage.ToLowerInvariant();
List <MobileResource> matchingResources = new List <MobileResource>();
for (int ctr = 0; ctr < this._resources.Count; ctr++)
{
MobileResource resource = _resources[ctr];
//Compute for the distance using Levenshtein Distance Algorithm
double distance = MobileLevenshteinDistance.CalcDistance(resource.Name, intendedPage); // both in lower case
//Divide it by resource name length for more accuracy
double meanDistancePerLetter = (distance / resource.Name.Length);
resource.Distance = meanDistancePerLetter;
if (meanDistancePerLetter <= showPageNotFoundDistance)
{
matchingResources.Add(resource);
}
}
// Sort to get the best
matchingResources.Sort(CompareByDistance);
int count = 0;
if (matchingResources.Count > numberOfSuggestedLinks)
{
count = matchingResources.Count - numberOfSuggestedLinks;
}
// remove the excess base on the set limit in 404.NumberOfSuggestedLinks appconfig
matchingResources.RemoveRange(0, count);
if (matchingResources.Count > 0)
{
DisplaySuggestions(matchingResources);
}
}
