Google like autosuggest with Lucene.net - lucene.net

Question

I have a Lucene index that stores customers that basically includes a view model (documents fields that are stored and not indexed), an ID (field stored and indexed to permit find and update of document), and a list of terms covered by the google-like search (multiple field instances of name Term). Terms may be field in the view model or not.
This works fine for the actual searching of documents by term. The question is how I can implement auto-suggest, basically get a list of Term (the field, not Lucene Term) values that might be the continuation of the entered value (i.e. "Co" might result in "Colorado", "Coloring Book", etc because those are actual values in at least one Document's Term field.

Answer 1

Theres a lot of way to do this, but if you need a quick and simple way to do it, use a TermEnum.
Just paste this little code sample in a new C# console application and check if it works for you to start from.
RAMDirectory dir = new RAMDirectory();
IndexWriter iw = new IndexWriter(dir, new KeywordAnalyzer(), IndexWriter.MaxFieldLength.UNLIMITED);
Document d = new Document();
Field f = new Field("text", "", Field.Store.YES, Field.Index.ANALYZED);
d.Add(f);
f.SetValue("abc");
iw.AddDocument(d);
f.SetValue("colorado");
iw.AddDocument(d);
f.SetValue("coloring book");
iw.AddDocument(d);
iw.Commit();
IndexReader reader = iw.GetReader();
TermEnum terms = reader.Terms(new Term("text", "co"));
int maxSuggestsCpt = 0;
// will print:
// colorado
// coloring book
do
{
Console.WriteLine(terms.Term.Text);
maxSuggestsCpt++;
if (maxSuggestsCpt >= 5)
break;
}
while (terms.Next() && terms.Term.Text.StartsWith("co"));
reader.Dispose();
iw.Dispose();