Develop Reference

CSharpScript.EvaluateAsync not recognising enum

I am using CSharpScript.EvaluateAsync to generate a predicate from a string. Using string and int variables it works fine but if I try to pass in an enum variable in the string to convert it throws the error:
Message "(1,26): error CS0103: The name 'Status' does not exist in the current context" string
Here is the standalone reproduction:
using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.CodeAnalysis.CSharp.Scripting;
using Microsoft.CodeAnalysis.Scripting;
namespace PredicateParser
{
class Program
{
static void Main(string[] args)
{
var albums = new List<Album>
{
new Album { Quantity = 10, Artist = "Betontod", Title = "Revolution", Status = Status.Offline},
new Album { Quantity = 50, Artist = "The Dangerous Summer", Title = "The Dangerous Summer", Status = Status.Offline },
new Album { Quantity = 200, Artist = "Depeche Mode", Title = "Spirit", Status = Status.Online },
};
var albumFilter1 = "album => album.Quantity > 20 && album.Quantity < 200"; //works fine
var albumFilter2 = "album => album.Status == Status.Online"; //Throws exception
var predicate1 = CreatePredicate<Album>(albumFilter1);
var predicate2 = CreatePredicate<Album>(albumFilter2);
var filteredAlbums1 = albums.Where(predicate1).ToList();
var filteredAlbums2 = albums.Where(predicate2).ToList();
}
public static Func<T, bool> CreatePredicate<T>(string command)
{
var options = ScriptOptions.Default.AddReferences(typeof(T).Assembly);
Func<T, bool> predicate = CSharpScript.EvaluateAsync<Func<T, bool>>(command, options).Result;
return predicate;
}
}
public class Album
{
public int Quantity { get; set; }
public string Title { get; set; }
public string Artist { get; set; }
public Status Status { get; set; }
}
public enum Status
{
Online,
Offline
}
}
How can I get it to work with enums?

var options = ScriptOptions.Default.AddReferences(typeof(T).Assembly).AddImports(nameof(PredicateParser));
You forgot to add "using namespace" :)

In this case, there's no error if you fully qualify it with the namespace.
"album => album.Status == PredicateParser.Status.Online"

Read a XML with Linq C# using where condition

I try to make a little Service for my business but it doesn't works.
<item>
<key>12323</key>
<summary></summary>
<reporter username="12313asdf">1232 asdf iii</reporter>
<cusomfields>
<customfield id="customfield_37723" key="xyz">
<customfieldname>First Name</customfieldname>
<customfieldvalues>
<customfieldvalue>Klaus</customfieldvalue>
</customfieldvalues>
</customfield>
//...many customfields
</customfields>
</item>
I created a c# method with this code -> but it doesn't work :(
XDocument doc = XDocument.Load(fileName);
var obj = (from c in doc.Descendants("item")
select new ServiceRequest_NewUser()
{
TicketID = c.Element("key").Value,
Summary = c.Element("summary").Value,
ReporterNT = c.Element("reporter").Attribute("username").Value,
ReporterFull = c.Element("reporter").Value,
FirstName = (from f in c.Descendants("customfields")
where f.Element("customfield")?.Attribute("id")?.Value == "customfield_37723"
select f.Descendants("customfieldvalues").FirstOrDefault()?.Value).FirstOrDefault()
}).ToList();
foreach (var i in obj)
{
var test = i.FirstName;
Console.WriteLine($"{i.TicketID} {i.Summary} {i.ReporterNT} {i.ReporterFull} {i.FirstName}");
}
Where is my fault? I did a alternative version of code in the comment tag. I need to output the value "Klaus".
I thank you in advance for the help.

If you expected to see Klaus in the FirstName, you should write this:
var obj = (from c in doc.Elements("item")
select new
{
TicketID = c.Element("key")?.Value,
Summary = c.Element("summary")?.Value,
ReporterNT = c.Element("reporter")?.Attribute("username")?.Value,
ReporterFull = c.Element("reporter").Value,
FirstName = (from f in c.Descendants("customfields")
where f.Element("customfield")?.Attribute("id")?.Value == "customfield_37723"
select f.Descendants("customfieldvalues").FirstOrDefault()?.Value).FirstOrDefault()
}).ToList();

Try following :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
namespace ConsoleApplication1
{
class Program
{
const string FILENAME = #"c:\temp\test.xml";
static void Main(string[] args)
{
XDocument doc = XDocument.Load(FILENAME);
List<Item> items = doc.Descendants("item").Select(x => new Item()
{
key = (string)x.Element("key"),
summary = (string)x.Element("summary"),
usernameText = (string)x.Element("reporter"),
username = (string)x.Element("reporter").Attribute("username"),
fields = x.Descendants("customfield").Select(y => new Field()
{
id = (string)y.Attribute("id"),
key = (string)y.Attribute("key"),
name = (string)y.Element("customfieldname"),
values = y.Descendants("customfieldvalue").Select(z => (string)z).ToList()
}).ToList()
}).ToList();
List<Item> customfield_37723 = items.Where(x => x.fields.Any(y => y.id == "customfield_37723")).ToList();
foreach (Item item in customfield_37723)
{
Console.WriteLine("Item : key = '{0}', summary = '{1}', username Text = '{2}', username = '{3}'",
item.key, item.summary, item.usernameText, item.username);
foreach (Field field in item.fields)
{
Console.WriteLine(" Field : id = '{0}', key = '{1}', name = '{2}', values = '{3}'",
field.id, field.key, field.name, string.Join(",", field.values));
}
}
Console.ReadLine();
}
}
public class Item
{
public string key { get; set; }
public string summary { get; set; }
public string usernameText { get; set; }
public string username { get; set; }
public List<Field> fields { get; set; }
}
public class Field
{
public string id { get; set; }
public string key { get; set; }
public string name { get; set; }
public List<string> values { get; set; }
}
}

MongoDB and C# Find()

I have the below code and I am new to mongodb, I need help in finding an specific element in the collection.
using MongoDB.Bson;
using MongoDB.Driver;
namespace mongo_console {
public class User {
public ObjectId Id { get; set; }
public string name { get; set; }
public string pwd { get; set; }
}
class Program {
static void Main(string[] args)
{
MongoClient client = new MongoClient();
MongoServer server = client.GetServer();
MongoDatabase db = server.GetDatabase("Users");
MongoCollection<User> collection = db.GetCollection<User>("users");
User user = new User
{
Id = ObjectId.GenerateNewId(),
name = "admin",
pwd = "admin"
};
User user2 = new User
{
Id = ObjectId.GenerateNewId(),
name = "system",
pwd = "system"
};
collection.Save(user);
collection.Save(user2);
/*
* How do I collection.Find() for example using the name
*/
}
}
}
Once I find the user I will like to print it, is that posible or will find only return the position? if so, how do I print it?
I have seen some examples collection.Find(x => x.something) but I do not know what that x is or mean

To find a record you could use Lambda in find, for example:
var results = collection.Find(x => x.name == "system").ToList();
Alternatively you can use Builders which work with strongly typed Lambda or text:
var filter = Builders<User>.Filter.Eq(x => x.name, "system")
Or
var filter = Builders<User>.Filter.Eq("name", "system")
And then use find as above
// results will be a collection of your documents matching your filter criteria
// Sync syntax
var results = collection.Find(filter).ToList();
// Async syntax
var results = await collection.Find(filter).ToListAsync();

It also Varies according to the .Net framework version we are using. If we Use 2x driver it should look like :
var list = await collection.Find(new BsonDocument()).ToListAsync();
method 2
await collection.Find(new BsonDocument()).ForEachAsync(X=>Console.WriteLine(X));
Reference Example

using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
using MongoDB.Driver;
using MongoDB.Driver.Builders;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Mongo_console
{
class Program
{
public static void Main(string[] args)
{
MongoClient client = new MongoClient();
MongoServer server = client.GetServer();
MongoDatabase db = server.GetDatabase("admin");
MongoCollection<Book> collection = db.GetCollection<Book>("Book");
Book book1 = new Book
{
Id = ObjectId.GenerateNewId(),
name = "Reel To Real"
};
Book book2 = new Book
{
Id = ObjectId.GenerateNewId(),
name = "Life"
};
collection.Save(book1);
collection.Save(book2);
var query = Query<Book>.EQ(u => u.Id, new ObjectId("5a5ee6360222da8ad498f3ff"));
Book list = collection.FindOne(query);
Console.WriteLine( "Book Name " + list.name);
Console.ReadLine();
}
}
public class Book
{
[BsonId]
public ObjectId Id { get; set; }
public string name { get; set; }
public Book()
{
}
public Book(ObjectId id, string name)
{
this.Id = id;
this.name = name;
}
}
}

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..
}

SQLite query in Windows Store App return nothing

As i said in the title the query that i written retun nothing while the same tried in Valentina Studio to check the database work fine and i don't understand whats wrong.
Here the code:
using System;
using System.Collections.Generic;
using System.Text;
using SQLite;
namespace SQLite_Analizer
{
public class sqlite_master
{
public string name { get; set; }
}
public class manager
{
public List<string> GetListTables(string DBName)
{
List<string> tablesList = new List<string>();
string itemName = null;
var con = new SQLiteAsyncConnection(DBName);
var query = con.QueryAsync<sqlite_master>("SELECT name FROM sqlite_master WHERE type='table' AND NOT SUBSTR(name,1,6) = 'sqlite' ORDER BY name").GetAwaiter().GetResult();
foreach(var tablesItem in query)
{
itemName = "\n" + tablesItem.name + "\n\n";
tablesList.Add(itemName);
}
return tablesList;
}
}
}
Here the new code with a counter to check query result number.
using System;
using System.Collections.Generic;
using System.Text;
using SQLite;
namespace SQLite_Analizer
{
public class sqlite_master
{
public string name { get; set; }
}
public class manager
{
private List<string> tablesList;
private int count;
public manager()
{
tablesList = new List<string>();
count = 0;
}
public List<string> getList()
{
return tablesList;
}
public int getCount()
{
return count;
}
public async void GetListTables(string DBName)
{
string itemName = null;
var con = new SQLiteAsyncConnection(DBName);
var query = await con.QueryAsync<sqlite_master>("SELECT name FROM sqlite_master WHERE type='table' AND NOT SUBSTR(name,1,6) = 'sqlite' ORDER BY name");
foreach (var tablesItem in query)
{
itemName = "\n" + tablesItem.name + "\n\n";
tablesList.Add(itemName);
}
count = query.Count;
}
}
}

I would try something like this
public async List<string> GetListTables(string DBName)
{
List<string> tablesList = new List<string>();
string itemName = null;
var con = new SQLiteAsyncConnection(DBName);
var query = await con.QueryAsync<sqlite_master>("SELECT name FROM sqlite_master WHERE type='table' AND NOT SUBSTR(name,1,6) = 'sqlite' ORDER BY name");
foreach(var tablesItem in query)
{
itemName = "\n" + tablesItem.name + "\n\n";
tablesList.Add(itemName);
}
return tablesList;
}