Develop Reference

Output an ordered collection (using LINQ) into a listbox

I want to order a text file using LINQ by date and output all columns into a listbox.
For example the input file is:
Name,Age,DOB,Male
Mary,28,01/01/1991,False
Anne,29,06/06/1989,False
John,18,06/07/2000,True
class Name
{
public double Age { get; set;}
public string Name{ get; set; }
public DateTime Date { get; set; }
public string Male { get; set; }
public Name()
{
}
public Name(string name, double age, DateTime date, string male)
{
Course = course;
Amount = amount;
Date = date;
Male = male;
}
}
private IEnumerable<Name> ReadName()
{
List<Name> dataCollection = new List<Name>();
using (var f = new StreamReader(#"R:\Data.txt"))
{
string line = string.Empty;
while ((line = f.ReadLine()) != null)
{
var data = line.Split(',');
dataCollection.Add(new Name(data[0], Convert.ToDouble(data[1]),Convert.ToDateTime(data[2]), data[3]));
}
}
return dataCollection;
}
private void btnDOBOrder_Click(object sender, EventArgs e)
{
lstByDate.Items.Clear();
IEnumerable<Name> names = ReadName();
var DateOrder = name
.OrderByDescending(x => x.Date)
.ToList();
lstByDate.DataSource = DateOrder;
}
Name Age DOB Male
John 18 06/07/2000 True
Mary 28 01/01/1991 False
Anne 29 06/06/1989 False
The current output in the listbox is:
Form1.Name
Form1.Name
Form1.Name

You are writing on listbox the string representation of your Name Class? If yes you just have to override ToString method in your Name class to display what information you want

ListBox's display collections of ListItems, and those have Text and Value properties that control what they display. You could project your collection into an anonymous type before databinding, then set the the DataValueField and DataTextField to your computed properties. It could look something like this:
var DateOrder = names.OrderByDescending(x => x.Date)
.Select(x => new { Text = $"{x.Name} {x.Age} {x.DOB} {x.Male}", Value = x.Name })
.ToList();
lstByDate.DataSource = DateOrder;
lstByDate.DataValueField = "Value";
lstByDate.DataTextField = "Text";

Try ICompare :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Data;
using System.Xml;
using System.Xml.Linq;
namespace ConsoleApplication100
{
class Program
{
const string FILENAME = #"c:\temp\test.csv";
static void Main(string[] args)
{
Person person = new Person(FILENAME);
person.Sort();
}
}
public class Person : IComparable
{
public string Name { get;set;}
public int Age { get;set;}
public DateTime DOB { get;set;}
public string sex { get;set;}
List<Person> dataCollection = new List<Person>();
public Person() { }
public Person(string filename)
{
using (var f = new StreamReader(filename))
{
string line = string.Empty;
int rowCount = 0;
while ((line = f.ReadLine()) != null)
{
if (++rowCount > 1)
{
var data = line.Split(',');
dataCollection.Add(new Person() { Name = data[0], Age = Convert.ToInt32(data[1]), DOB = Convert.ToDateTime(data[2]), sex = data[3]});
}
}
}
}
public int CompareTo(object obj)
{
return this.DOB.CompareTo(((Person)obj).DOB);
}
public void Sort()
{
dataCollection.Sort();
}
}
}

Parse XML data with Multiple List & Class objects using LINQ-To-XML in C#

Let's say I want to parse following XML file:
<EmployeeDetails>
<Employee> //List of Employees
<Id>11</Id>
<name>a</name>
<Dependents> //List of Dependents of a single employee
<Dependent>
<name>a1</name>
<age>50</age>
</Dependent>
<Dependent>
<name>a2</name>
<age>52</age>
</Dependent>
</Dependents>
<Department> //Unique per Emp
<DeptId>1</DeptId>
<DeptName>D1</DeptName>
</Department>
</Employee>
<Employee>
-----
--------
</Employee>
</EmployeeDetails>
Following is the Class Structure for above file:
public class Employee
{
public int id {get; set;}
public string name {get; set;}
public List<Dependents> Dependents {get; set;}
public Department Department {get; set;}
}
public class Dependents
{
public string name {get; set;}
public int age {get; set;}
}
public class Department
{
public int DeptId {get; set;}
public string DeptName {get; set;}
}
Now, I want to parse above XML structure and I am able to do it for id and name of Employee but I am unable to parse further.
Let me show you what I've done so far :
public static void ParseXml()
{
string xmldoc = //let's assume I've data in this string
XDocument xdoc = new XDocument();
xdoc = XDocument.Parse(xmldoc);
var query = from d in xdoc.Root.Descendants("Employee")
select d;
List<Employee> lsEmp = new List<Employee>();
foreach (var q in query)
{
Employee obj = new Employee();
obj.Id = Convert.ToInt32(q.Element("Id").Value);
obj.name = q.Element("name").Value;
obj.Department = new Department();
obj.Dependents = new List<Dependents>();
// how to get data further?
lsEmp.Add(obj);
}
So I need help in order to parse XML data from these list of Dependents and Department object.

Following your own structure, here's the way to continue parsing the data you need.
// how to get data further?
var allDependents = q.Elements("Dependents").Elements("Dependent");
foreach (var b in allDependents)
{
Dependents d = new Dependents
{
age = Convert.ToInt32(b.Element("age").Value),
name = b.Element("name").Value
};
obj.Dependents.Add(d);
}
obj.Department.DeptId = Convert.ToInt32(q.Element("Department").Element("DeptId").Value);
obj.Department.DeptName = q.Element("Department").Element("DeptName").Value;
Notice that I have used .Elements("") to get all the child nodes under Dependents

Here is code using just linq and no for loops
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.IO;
namespace ConsoleApplication1
{
class Program
{
const string FILENAME = #"c:\temp\test.xml";
static void Main(string[] args)
{
string xml = File.ReadAllText(FILENAME);
ParseXml(xml);
}
public static void ParseXml(string xml)
{
XDocument xdoc = XDocument.Parse(xml);
List<Employee> employees = xdoc.Descendants("Employee").Select(x => new Employee () {
id = (int)x.Element("Id"),
name = (string)x.Element("Name"),
Department = x.Elements("Department").Select(y => new Department() { DeptId = (int)y.Element("DeptId"), DeptName = (string)y.Element("DeptName")}).FirstOrDefault(),
Dependents = x.Descendants("Dependent").Select(y => new Dependents() { age = (int)y.Element("age"), name = (string)y.Element("name")}).ToList()
}).ToList();
}
}
public class Employee
{
public int id { get; set; }
public string name { get; set; }
public List<Dependents> Dependents { get; set; }
public Department Department { get; set; }
}
public class Dependents
{
public string name { get; set; }
public int age { get; set; }
}
public class Department
{
public int DeptId { get; set; }
public string DeptName { get; set; }
}
}

Maybe this can help you:
XDocument xdoc = new XDocument();
xdoc = XDocument.Parse(xmldoc);
var query = from d in xdoc.Root.Descendants("Employee")
select d;
List<Employee> lsEmp = new List<Employee>();
foreach (var q in query)
{
Employee obj = new Employee();
obj.Id = Convert.ToInt32(q.Element("Id").Value);
obj.name = q.Element("name").Value;
obj.Department = new Department()
{
DeptName = q.Element("Department").Element("name").Value,
DeptId =
Convert.ToInt32(q.Element("Department").Element("age").Value)
};
obj.Dependents = new List<Dependents>();
foreach (var e in q.Element("Dependents").Elements("Dependent"))
{
var dependent = new Dependents()
{
name = e.Element("name").Value,
age = Convert.ToInt32(e.Element("age").Value)
};
obj.Dependents.Add(dependent);
}
lsEmp.Add(obj);
}

Trouble getting MemberName of "Name" from CustomAttributes = ColumnAttribute of Linq Table Class

I have a little algo I wrote to compare the Linq DataContext table to the sql table. It rolls through the properties of the Linq table and gets the CustomeAttributes of the property, (table columns). It's been working for years, but somebody created a table field with a # sign in it, (UPS#). Linq doesn't like such a name for its properties for obvious reasons. So, it has a member of the ColumnAttribute called "Name" to handle the swap. But, I've always used the "Storage" member for my column name. You would think you would just pick up the "Name" member if it's present, but I can't find it to save my life.
This is the code. Any help is very much appreciated.
public static ColumnInfo[] GetColumnsInfo(Type linqTableClass)
{
// Just looking in the loop to see if I missed something.
foreach (var fld in linqTableClass.GetProperties())
{
foreach (var attr in fld.CustomAttributes)
{
foreach (var arg in attr.NamedArguments)
{
if (arg.MemberName == "Name")
Debug.WriteLine(arg.MemberName);
Debug.WriteLine("{0}", arg.MemberName);
}
}
}
var columnInfoQuery =
from field in linqTableClass.GetProperties()
from attribute in field.CustomAttributes
from namedArgument in attribute.NamedArguments
where namedArgument.MemberName == "DbType"
select new ColumnInfo
{
//ColumnName = field.Name,
ColumnName = namedArgument.MemberName,
DatabaseType = namedArgument.TypedValue.Value.ToString(),
};
return columnInfoQuery.ToArray();
}
and this is the property in the Table Class:
[global::System.Data.Linq.Mapping.ColumnAttribute(Name="PEER_UPS#", Storage="_PEER_UPS_", DbType="Char(31) NOT NULL", CanBeNull=false)]
public string PEER_UPS_
{
get
{
return this._PEER_UPS_;
}
set
{
if ((this._PEER_UPS_ != value))
{
this.OnPEER_UPS_Changing(value);
this.SendPropertyChanging();
this._PEER_UPS_ = value;
this.SendPropertyChanged("PEER_UPS_");
this.OnPEER_UPS_Changed();
}
}
}

I couldn't find a pretty way to get this done. For some reason the ColumnAttribute just didn't want to play nice. Ugly as this is, it works.
public class ColumnInfo
{
public string ColumnName { get; set; }
public string DatabaseType { get; set; }
}
public static IEnumerable<ColumnInfo> GetColumnsInfo(Type linqTableClass)
{
Debug.WriteLine(string.Format("Table: {0}", linqTableClass.Name));
/// In-Case this has to grow in the future. Using a list for the arg names to search for.
/// The primary arg should be in position 0 of the array.
string dbTypeArgName = "DbType";
string fldPrimayName = "Storage";
string fldSecondaryName = "Name";
List<string> fldArgnames = new List<string>() { fldPrimayName, fldSecondaryName };
foreach (var fld in linqTableClass.GetProperties())
{
Debug.WriteLine(string.Format("Field Name: {0}", fld.Name));
foreach (var attr in fld.GetCustomAttributesData().Cast<CustomAttributeData>()
.Where(r => r.AttributeType == typeof(ColumnAttribute))
.Where(a => a.NamedArguments
.Select(n => n.MemberName)
.Intersect(fldArgnames)
.Any()))
{
var fldName = attr.NamedArguments.Where(r => r.MemberName == fldSecondaryName).Count() != 0
? attr.NamedArguments.Where(r => r.MemberName == fldSecondaryName).SingleOrDefault().TypedValue.Value.ToString()
: fld.Name;
var fldType = attr.NamedArguments
.Where(r => r.MemberName == dbTypeArgName)
.Select(r => r.TypedValue.Value.ToString())
.SingleOrDefault();
Debug.WriteLine(string.Format("\tTable Field Name {0} Table Type {1}", fldName, fldType));
yield return new ColumnInfo()
{
ColumnName = fldName,
DatabaseType = fldType,
};
}
}
}

and here is what i suggest:
[sorry, my first example was indeed too simplistic]
Here is how i'd do it:
namespace LinqAttributes
{
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Linq;
public class ColumnInfo
{
public string ColumnName { get; set; }
public string DatabaseType { get; set; }
}
public class Test
{
[System.Data.Linq.Mapping.ColumnAttribute(Name = "Whatever", Storage = "Whatever", DbType = "Char(20)", CanBeNull = true)]
public string MyProperty { get; set; }
[System.Data.Linq.Mapping.ColumnAttribute(Name = "PEER_UPS#", Storage = "_PEER_UPS_", DbType = "Char(31) NOT NULL", CanBeNull = false)]
public string PEER_UPS_ { get; set; }
}
internal class Program
{
public static IEnumerable<ColumnInfo> GetColumnsInfo(Type type)
{
foreach (PropertyDescriptor descriptor in TypeDescriptor.GetProperties(type))
{
var columnAttribute = descriptor.Attributes
.OfType<System.Data.Linq.Mapping.ColumnAttribute>().SingleOrDefault();
if (columnAttribute != null)
{
yield return new ColumnInfo
{
ColumnName = columnAttribute.Name,
DatabaseType = columnAttribute.DbType
};
}
}
}
private static void Main(string[] args)
{
foreach (var item in GetColumnsInfo(typeof(Test)))
{
Debug.WriteLine(item.ColumnName);
}
}
}
}
Just tested it.
Cheers!

public class City
{
public City() { }
[Column("id_city")]
public int Id { get; private set; }
}
var obj = new City();
var pro = obj.GetType().GetProperties();
string columnAttribute = pro.GetCustomAttributes<ColumnAttribute>().FirstOrDefault().Name;
if(columnAttribute == "id_city") {
//sucess
}

How to do Cascading Include in LiteDB

here is example on how to store cross-referenced entities in LiteDB. LiteDB stores the cross-referenced entities perfectly fine, but problem comes when I am trying to find/load entities back. My goal is NOT ONLY the requested entity but also referenced ones. There is quick tutorial section "DbRef for cross references" on LiteDB webpage how one can realize it. LiteDB has "Include" option (which is called before "FindAll") which says which referenced entities must be loaded as well. I am trying to achieve it in this code example but with no results, i.e, the code raises Exception("D_Ref") meaning "D_Ref" reference is not loaded:
namespace _01_simple {
using System;
using LiteDB;
public class A {
public int Id { set; get; }
public string Name { set; get; }
public B B_Ref { set; get; }
}
public class B {
public int Id { set; get; }
public string Name { set; get; }
public C C_Ref { set; get; }
}
public class C {
public int Id { set; get; }
public string Name { set; get; }
public D D_Ref { set; get; }
}
public class D {
public int Id { set; get; }
public string Name { set; get; }
}
class Program {
static void Main(string[] args) {
test_01();
}
static string NameInDb<T>() {
var name = typeof(T).Name + "s";
return name;
}
static void test_01() {
if (System.IO.File.Exists(#"MyData.db"))
System.IO.File.Delete(#"MyData.db");
using (var db = new LiteDatabase(#"MyData.db")) {
var As = db.GetCollection<A>(NameInDb<A>());
var Bs = db.GetCollection<B>(NameInDb<B>());
var Cs = db.GetCollection<C>(NameInDb<C>());
var Ds = db.GetCollection<D>(NameInDb<D>());
LiteDB.BsonMapper.Global.Entity<A>().DbRef(x => x.B_Ref, NameInDb<B>());
LiteDB.BsonMapper.Global.Entity<B>().DbRef(x => x.C_Ref, NameInDb<C>());
LiteDB.BsonMapper.Global.Entity<C>().DbRef(x => x.D_Ref, NameInDb<D>());
var d = new D { Name = "I am D." };
var c = new C { Name = "I am C.", D_Ref = d };
var b = new B { Name = "I am B.", C_Ref = c };
var a = new A { Name = "I am A.", B_Ref = b };
Ds.Insert(d);
Cs.Insert(c);
Bs.Insert(b);
As.Insert(a);
}
using (var db = new LiteDatabase(#"MyData.db")) {
var As = db.GetCollection<A>(NameInDb<A>());
var all_a = As
.Include(x => x.B_Ref)
.FindAll();
foreach (var a in all_a) {
if (a.B_Ref == null)
throw new Exception("B_Ref");
if (a.B_Ref.C_Ref == null)
throw new Exception("C_Ref");
if (a.B_Ref.C_Ref.D_Ref == null)
throw new Exception("D_Ref");
}
}
}
}}

after small research I've resolved the issue simply by adding extra "Include" parameterize by "x => x.B_Ref.C_Ref" lambda where x.B_Ref.C_Ref is a path in hierarchy of references:
var all_a = As
.Include(x => x.B_Ref)
.Include(x => x.B_Ref.C_Ref)
.FindAll();
Here is complete example
namespace _01_simple {
using System;
using LiteDB;
public class A {
public int Id { set; get; }
public string Name { set; get; }
public B B_Ref { set; get; }
}
public class B {
public int Id { set; get; }
public string Name { set; get; }
public C C_Ref { set; get; }
}
public class C {
public int Id { set; get; }
public string Name { set; get; }
public D D_Ref { set; get; }
}
public class D {
public int Id { set; get; }
public string Name { set; get; }
}
class Program {
static void Main(string[] args) {
test_01();
}
static string NameInDb<T>() {
var name = typeof(T).Name + "s";
return name;
}
static void test_01() {
if (System.IO.File.Exists(#"MyData.db"))
System.IO.File.Delete(#"MyData.db");
using (var db = new LiteDatabase(#"MyData.db")) {
var As = db.GetCollection<A>(NameInDb<A>());
var Bs = db.GetCollection<B>(NameInDb<B>());
var Cs = db.GetCollection<C>(NameInDb<C>());
var Ds = db.GetCollection<D>(NameInDb<D>());
LiteDB.BsonMapper.Global.Entity<A>().DbRef(x => x.B_Ref, NameInDb<B>());
LiteDB.BsonMapper.Global.Entity<B>().DbRef(x => x.C_Ref, NameInDb<C>());
LiteDB.BsonMapper.Global.Entity<C>().DbRef(x => x.D_Ref, NameInDb<D>());
var d = new D { Name = "I am D." };
var c = new C { Name = "I am C.", D_Ref = d };
var b = new B { Name = "I am B.", C_Ref = c };
var a = new A { Name = "I am A.", B_Ref = b };
Ds.Insert(d);
Cs.Insert(c);
Bs.Insert(b);
As.Insert(a);
}
using (var db = new LiteDatabase(#"MyData.db")) {
var As = db.GetCollection<A>(NameInDb<A>());
var all_a = As
.Include(x => x.B_Ref)
.Include(x => x.B_Ref.C_Ref)
.Include(x => x.B_Ref.C_Ref.D_Ref)
.FindAll();
foreach (var a in all_a) {
if (a.B_Ref == null)
throw new Exception("B_Ref");
if (a.B_Ref.C_Ref == null)
throw new Exception("C_Ref");
if (a.B_Ref.C_Ref.D_Ref == null)
throw new Exception("D_Ref");
}
}
}
}}
I hope it saves someone's time.
Update: LiteDB author says there is no support for Cascading Include. But it is planned in the next version (see issue). Consider, once, let say, B_Ref is a Lite of B, then there is no mechanism to force deeper Include.

Using Apache Lucene to search

I've been trying to implement Lucene to make the searching on my website faster.
My code currently works, however, I think I am not correctly making use of Lucene. Right now, my search query is productName:asterisk(input)asterisk - I can't imagine this is what you're supposed to do to find all products where productName contains input. I think it has something to do with the way I save the fields to a document.
My code:
LuceneHelper.cs
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data.Entity.Migrations.Model;
using System.Linq;
using System.Threading.Tasks;
using Lucene.Net;
using Lucene.Net.Analysis;
using Lucene.Net.Analysis.Standard;
using Lucene.Net.Documents;
using Lucene.Net.Index;
using Lucene.Net.QueryParsers;
using Lucene.Net.Search;
using Lucene.Net.Store;
using Rentpro.Models;
using RentPro.Models.Tables;
using RentProModels.Models;
namespace RentPro.Helpers
{
public class LuceneHelper
{
private const Lucene.Net.Util.Version Version = Lucene.Net.Util.Version.LUCENE_30;
private bool IndicesInitialized;
private List<Language> Languages = new List<Language>();
public void BuildIndices(DB db)
{
Languages = GetLanguages(db);
Analyzer analyzer = new StandardAnalyzer(Version);
List<Product> allProducts = db.GetAllProducts(true, false);
foreach (Language l in Languages)
{
BuildIndicesForLanguage(allProducts, analyzer, l.ID);
}
IndicesInitialized = true;
}
private void BuildIndicesForLanguage(List<Product> products, Analyzer analyzer, int id = 0)
{
using (
IndexWriter indexWriter = new IndexWriter(GetDirectory(id), analyzer,
IndexWriter.MaxFieldLength.UNLIMITED))
{
var x = products.Count;
foreach (Product p in products)
{
SearchProduct product = SearchProduct.FromProduct(p, id);
Document document = new Document();
Field productIdField = new Field("productId", product.ID.ToString(), Field.Store.YES, Field.Index.NO);
Field productTitleField = new Field("productName", product.Name, Field.Store.YES, Field.Index.ANALYZED);
Field productDescriptionField = new Field("productDescription", product.Description, Field.Store.YES, Field.Index.ANALYZED);
Field productCategoryField = new Field("productCategory", product.Category, Field.Store.YES, Field.Index.ANALYZED);
Field productCategorySynonymField = new Field("productCategorySynonym", product.CategorySynonym, Field.Store.YES, Field.Index.ANALYZED);
Field productImageUrlField = new Field("productImageUrl", product.ImageUrl, Field.Store.YES, Field.Index.NO);
Field productTypeField = new Field("productType", product.Type, Field.Store.YES, Field.Index.NO);
Field productDescriptionShortField = new Field("productDescriptionShort", product.DescriptionShort, Field.Store.YES, Field.Index.NO);
Field productPriceField = new Field("productPrice", product.Price, Field.Store.YES, Field.Index.NO);
document.Add(productIdField);
document.Add(productTitleField);
document.Add(productDescriptionField);
document.Add(productCategoryField);
document.Add(productCategorySynonymField);
document.Add(productImageUrlField);
document.Add(productTypeField);
document.Add(productDescriptionShortField);
document.Add(productPriceField);
indexWriter.AddDocument(document);
}
indexWriter.Optimize();
indexWriter.Commit();
}
}
public List<SearchProduct> Search(string input)
{
if (!IndicesInitialized)
{
BuildIndices(new DB());
return Search(input);
}
IndexReader reader = IndexReader.Open(GetCurrentDirectory(), true);
Searcher searcher = new IndexSearcher(reader);
Analyzer analyzer = new StandardAnalyzer(Version);
TopScoreDocCollector collector = TopScoreDocCollector.Create(100, true);
MultiFieldQueryParser parser = new MultiFieldQueryParser(Version,
new[] { "productDescription", "productCategory", "productCategorySynonym", "productName" }, analyzer)
{
AllowLeadingWildcard = true
};
searcher.Search(parser.Parse("*" + input + "*"), collector);
ScoreDoc[] hits = collector.TopDocs().ScoreDocs;
List<int> productIds = new List<int>();
List<SearchProduct> results = new List<SearchProduct>();
foreach (ScoreDoc scoreDoc in hits)
{
Document document = searcher.Doc(scoreDoc.Doc);
int productId = int.Parse(document.Get("productId"));
if (!productIds.Contains(productId))
{
productIds.Add(productId);
SearchProduct result = new SearchProduct
{
ID = productId,
Description = document.Get("productDescription"),
Name = document.Get("productName"),
Category = document.Get("productCategory"),
CategorySynonym = document.Get("productCategorySynonym"),
ImageUrl = document.Get("productImageUrl"),
Type = document.Get("productType"),
DescriptionShort = document.Get("productDescriptionShort"),
Price = document.Get("productPrice")
};
results.Add(result);
}
}
reader.Dispose();
searcher.Dispose();
analyzer.Dispose();
return results;
}
private string GetDirectoryPath(int languageId = 1)
{
return GetDirectoryPath(Languages.SingleOrDefault(x => x.ID == languageId).UriPart);
}
private string GetDirectoryPath(string languageUri)
{
return AppDomain.CurrentDomain.BaseDirectory + #"\App_Data\LuceneIndices\" + languageUri;
}
private List<Language> GetLanguages(DB db)
{
return db.Languages.ToList();
}
private int GetCurrentLanguageId()
{
return Translator.GetCurrentLanguageID();
}
private FSDirectory GetCurrentDirectory()
{
return FSDirectory.Open(GetDirectoryPath(GetCurrentLanguageId()));
}
private FSDirectory GetDirectory(int languageId)
{
return FSDirectory.Open(GetDirectoryPath(languageId));
}
}
public class SearchProduct
{
public int ID { get; set; }
public string Description { get; set; }
public string Name { get; set; }
public string ImageUrl { get; set; }
public string Type { get; set; }
public string DescriptionShort { get; set; }
public string Price { get; set; }
public string Category { get; set; }
public string CategorySynonym { get; set; }
public static SearchProduct FromProduct(Product p, int languageId)
{
return new SearchProduct()
{
ID = p.ID,
Description = p.GetText(languageId, ProductLanguageType.Description),
Name = p.GetText(languageId),
ImageUrl =
p.Images.Count > 0
? "/Company/" + Settings.Get("FolderName") + "/Pictures/Products/100x100/" +
p.Images.Single(x => x.Type == "Main").Url
: "",
Type = p is HuurProduct ? "HuurProduct" : "KoopProduct",
DescriptionShort = p.GetText(languageId, ProductLanguageType.DescriptionShort),
Price = p is HuurProduct ? ((HuurProduct)p).CalculatedPrice(1, !Settings.GetBool("BTWExLeading")).ToString("0.00") : "",
Category = p.Category.Name,
CategorySynonym = p.Category.Synonym
};
}
}
}
How I call the LuceneHelper:
public ActionResult Lucene(string SearchString, string SearchOrderBy, int? page, int? amount)
{
List<SearchProduct> searchResults = new List<SearchProduct>();
if (!SearchString.IsNullOrWhiteSpace())
{
LuceneHelper lucene = new LuceneHelper();
searchResults = lucene.Search(SearchString);
}
return View(new LuceneSearchResultsVM(db, SearchString, searchResults, SearchOrderBy, page ?? 1, amount ?? 10));
}
LuceneSearchResultsVM:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Dynamic;
using System.Web;
using RentPro.Models.Tables;
using System.Linq.Expressions;
using System.Reflection;
using Microsoft.Ajax.Utilities;
using Rentpro.Models;
using RentPro.Helpers;
using RentProModels.Models;
namespace RentPro.ViewModels
{
public class LuceneSearchResultsVM
{
public List<SearchProduct> SearchProducts { get; set; }
public bool BTWActive { get; set; }
public bool BTWEXInput { get; set; }
public bool BTWShow { get; set; }
public bool BTWExLeading { get; set; }
public string FolderName { get; set; }
public string CurrentSearchString { get; set; }
public string SearchOrderBy { get; set; }
public int Page;
public int Amount;
public String SearchQueryString {
get
{
return Translator.Translate("Zoekresultaten voor") + ": " + CurrentSearchString + " (" +
SearchProducts.Count + " " + Translator.Translate("resultaten") + " - " +
Translator.Translate("pagina") + " " + Page + " " + Translator.Translate("van") + " " +
CalculateAmountOfPages() + ")";
}
set { }
}
public LuceneSearchResultsVM(DB db, string queryString, List<SearchProduct> results, string searchOrderBy, int page, int amt)
{
BTWActive = Settings.GetBool("BTWActive");
BTWEXInput = Settings.GetBool("BTWEXInput");
BTWShow = Settings.GetBool("BTWShow");
BTWExLeading = Settings.GetBool("BTWExLeading");
FolderName = Settings.Get("FolderName");
SearchProducts = results;
CurrentSearchString = queryString;
if (searchOrderBy.IsNullOrWhiteSpace())
{
searchOrderBy = "Name";
}
SearchOrderBy = searchOrderBy;
Amount = amt == 0 ? 10 : amt;
int maxPages = CalculateAmountOfPages();
Page = page > maxPages ? maxPages : page;
SearchLog.MakeEntry(queryString, SearchProducts.Count(), db, HttpContext.Current.Request.UserHostAddress);
}
public List<SearchProduct> GetOrderedList()
{
List<SearchProduct> copySearchProductList = new List<SearchProduct>(SearchProducts);
copySearchProductList = copySearchProductList.Skip((Page - 1) * Amount).Take(Amount).ToList();
switch (SearchOrderBy)
{
case "Price":
copySearchProductList.Sort(new PriceSorter());
break;
case "DateCreated":
return copySearchProductList; //TODO
default:
return copySearchProductList.OrderBy(n => n.Name).ToList();
}
return copySearchProductList;
}
public int CalculateAmountOfPages()
{
int items = SearchProducts.Count;
return items / Amount + (items % Amount > 0 ? 1 : 0);
}
}
public class PriceSorter : IComparer<SearchProduct>
{
public int Compare(SearchProduct x, SearchProduct y)
{
if (x == null || x.Price == "") return 1;
if (y == null || y.Price == "") return -1;
decimal priceX = decimal.Parse(x.Price);
decimal priceY = decimal.Parse(y.Price);
return priceX > priceY ? 1 : priceX == priceY ? 0 : -1;
}
}
}
Any help would be greatly appreciated.
Example input list of products:
Query:
SELECT Product.ID, Product.Decription, Product.Name FROM Product
Desired results:
SQL Server query equivalent:
SELECT Product.ID, Product.Decription, Product.Name FROM Product WHERE Product.Name LIKE '%Zelf%' OR Product.Decription LIKE '%Zelf%'
Basically, Zelf is the input. I want to find all matches with product descriptions or product names that contain the input string.

ucene not allows to use ? or * as starting symbols of the searching term. To overcome this issue you need to store in your index a sub-strings from any position of word to it end position. E.g. for word test you should put to index
test
est
st
t
I recommend to use separate field for that. Java example for case if you have a short field with one word like a product name.
for(int i = 0; i < product.SafeName.length()-1; i++){
Field productTitleSearchField = new Field("productNameSearch", product.SafeName.substring(i, product.SafeName.length()), Field.Store.NO, Field.Index.ANALYZED);
}
After this you can use following query string
productNameSearch:(input)asterisk or use a PrefixQuery for searching product names containing input.
In case if you have several words in you field and for you will be enough to have some reasonable length of your input, then it will better to add for this field a NGramTokenFilter. You if have limit on your input string from n to m you should create a NGram Token Filter with n minGram and m maxGramm. If you has word test and you limit 2 to 3 you will have in your index words
te
tes
es
est
st
After this you can search via string
ngrammField:(input)

This doesn't answer your question but it is safer to use the using block in C#. In your current code, calling dispose can throw.
You're doing:
IndexReader reader = IndexReader.Open(GetCurrentDirectory(), true);
Searcher searcher = new IndexSearcher(reader);
Analyzer analyzer = new StandardAnalyzer(Version);
//...
reader.Dispose();
searcher.Dispose();
analyzer.Dispose();
Which can be replaced with:
using (IndexReader reader = IndexReader.Open(GetCurrentDirectory(), true))
using (Searcher searcher = new IndexSearcher(reader))
using (Analyzer analyzer = new StandardAnalyzer(Version))
{
//Do whatever else here.. No need to call "dispose".
}
The above is pretty much a try -> finally statement where it tries to do whatever is in the using statement. If anything throws, the finally block disposes the resources opened/allocated.
Another way (comma operator.. if all variables are of the same type) is:
using (whatever foo = new whatever(), whatever bar = new whatever(), ...)
{
//do whatever here..
}