Unity container and Factory pattern

Recently I had merged Unity container and Factory pattern to create objects in a central place. Below is the code for the same. Thought it would be useful to you guys!!

using Microsoft.Practices.Unity;
using Microsoft.Practices.Unity.Configuration;

public class DependencyFactory
    {
        public static T GetObject()
        {
            IUnityContainer container = new UnityContainer();
            UnityConfigurationSection section =
              (UnityConfigurationSection)ConfigurationManager.GetSection(ConfigurationManager.AppSettings["UnityContainer"]);
            section.Configure(container);
            T res = container.Resolve();
            return res;
        }

        public static T GetObject(params ResolverOverride[] overrides)
        {
            IUnityContainer container = new UnityContainer();
            UnityConfigurationSection section =
              (UnityConfigurationSection)ConfigurationManager.GetSection(ConfigurationManager.AppSettings["UnityContainer"]);
            section.Configure(container);
            T res = container.Resolve(overrides);
            return res;
        }
    }


  <configuration>
   <configSections>
    <section name="TEST_UNITY"
       type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, 
               Microsoft.Practices.Unity.Configuration" />
  </configSections>
  <TEST_UNITY>
    <containers>
      <container>
        <types>
          <type
             type="Unity.Sample.Repositories.IEnrollmentRepository,Unity.Sample"
             mapTo="Unity.Sample.Repositories.DummyEnrollmentRepository,
                      Unity.Sample" />
          <type
             type="Unity.Sample.Repositories.ICustomerDetailsRepository,Unity.Sample"
             mapTo="Unity.Sample.Repositories.DummyCustomerDetailsRepository,
                      Unity.Sample" />
          <type
             type="Unity.Sample.Repositories.ICustomerRepository,Unity.Sample"
             mapTo="Unity.Sample.Repositories.DummyCustomerRepository,
                      Unity.Sample" />
           <type
             type="Unity.Sample.Repositories.IBIBRepository,Unity.Sample"
             mapTo="Unity.Sample.Repositories.DummyBIBRepository,
                      Unity.Sample" />
          <type
             type="Unity.Sample.Repositories.ILockBoxRepository,Unity.Sample"
             mapTo="Unity.Sample.Repositories.DummyLockBoxRepository,
                      Unity.Sample" />
          <type
             type="Unity.Sample.Interfaces.IBIB,Unity.Sample"
             mapTo="Unity.Sample.Impl.DummyBIB,
                      Unity.Sample" />
          <type
               type="Unity.Sample.Interfaces.ILockBox,Unity.Sample"
               mapTo="Unity.Sample.Impl.DummyLockBox,
                      Unity.Sample" />
        </types>
      </container>
    </containers>
  </TEST_UNITY>
  <appSettings>
    <add key="UnityContainer" value="TEST_UNITY"/>
  </appSettings>
</configuration>

   
 

My experiments with TPL Dataflow

Another WOW technique from the house of Microsoft is the TPL Dataflow for dealing with collections in parallel utilizing the multiple CPU's available. I was doing some experiments with it recently and the code is below;

I implemented the below process using TPL;

class Program

    {

        static Employer employer = new Employer();

        static EmployeeCollection employees = new EmployeeCollection();

        static int i = 0;

        static void Main(string[] args)

        {

            LoadEmployees();

            PayEmployees();

        }

        static void LoadEmployees()

        {

            string fileName = @"C:\Users\m1003014\Desktop\employees.txt";

            var inputBlock = new BufferBlock();

            var processBlock = new TransformBlock(

                x =>

                {

                    Employee emp = null;

                    string[] values = x.Split(@";".ToCharArray());

                    BankAccount bankAccount = new BankAccount(Convert.ToDecimal(values[6]));

                    emp = new Employee(i++, values[0], values[1], Convert.ToDecimal(values[2]), bankAccount);

                    if (Convert.ToDecimal(values[3]) > 0)

                    {

                        emp.TakeAdvance(Convert.ToDecimal(values[3]), Convert.ToDecimal(values[4]), Convert.ToDecimal(values[5]));

                    }

                    return emp;

                });

            var outputBlock = new ActionBlock(

                x =>

                {

                    employees.Add(x);

                });

            using (inputBlock.LinkTo(processBlock))

            using (processBlock.LinkTo(outputBlock))

            {

                inputBlock.Completion.ContinueWith(t => processBlock.Complete());

                processBlock.Completion.ContinueWith(t => outputBlock.Complete());

                if (File.Exists(fileName))

                {

                    StreamReader sr = new StreamReader(fileName);

                    sr.ReadLine();

                    String line = sr.ReadLine();

                    do

                    {

                        inputBlock.Post(line);

                        line = sr.ReadLine();

                    } while (line != null);

                }

                inputBlock.Complete();

                outputBlock.Completion.Wait();

            }

        }

        static void PayEmployees()

        {

            var inputBlock = new BufferBlock();

            var processBlock = new TransformBlock(

                x =>

                {

                    employer.PaySalary(x);

                    return x;

                });

            var outputBlock = new ActionBlock(

                x =>

                {

                    Console.WriteLine(string.Format("The salary of '{1}' INR has been paid to '{0}'", x.FirstName, x.SalaryTobePaid));

                });

            using (inputBlock.LinkTo(processBlock))

            using (processBlock.LinkTo(outputBlock))

            {

                inputBlock.Completion.ContinueWith(t => processBlock.Complete());

                processBlock.Completion.ContinueWith(t => outputBlock.Complete());

                foreach (Employee emp in employees)

                {

                    inputBlock.Post(emp);

                }

                inputBlock.Complete();

                outputBlock.Completion.Wait();

            }

        }

    }

 public class Employee

    {

        int _id;

        string _firstName;

        string _lastName;

        decimal _salary;

        decimal _advanceTaken;

        decimal _monthlyDeduction;

        decimal _tenure;

        decimal _pendingTenure;

        decimal _advanceLeft;

        BankAccount _employeeBankAccount;

        public Employee(int id, string firstName, string lastName, decimal salary, BankAccount employeeBankAccount)

        {

            _id = id;

            _firstName = firstName;

            _lastName = lastName;

            _salary = salary;

            _employeeBankAccount = employeeBankAccount;

        }

        public int EmployeeID

        {

            get { return _id; }

        }

        public string FirstName

        {

            get { return _firstName; }

        }

        public string LastName

        {

            get { return _firstName; }

        }

        public decimal Salary

        {

            get { return _salary; }

        }

        public decimal AdvanceTaken

        {

            get { return _advanceTaken; }

        }

        public decimal AdvanceLeft

        {

            get { return _advanceLeft; }

        }

        public decimal SalaryTobePaid

        {

            get { return _salary - _monthlyDeduction; }

        }

        public BankAccount EmployeeBankAccount

        {

            get { return _employeeBankAccount; }

        }

        public void TakeAdvance(decimal amount, decimal monthlyDeduction, decimal tenure)

        {

            _advanceTaken = amount;

            _advanceLeft = amount;

            _monthlyDeduction = monthlyDeduction;

            _tenure = tenure;

            _pendingTenure = tenure;

        }

        public void UpdateAdvance()

        {

            _advanceLeft -= _monthlyDeduction;

            _pendingTenure -= 1;

        }

        public void CreditSalary()

        {

            _employeeBankAccount.Credit(SalaryTobePaid);

        }

        public bool HasTakenAdvance()

        {

            if (_pendingTenure > 0)

                return true;

            else

                return false;

        }

    }

    public class BankAccount

    {

        decimal _balance;

        public BankAccount(decimal balance)

        {

            _balance = balance;

        }

        public decimal Balance

        {

            get { return _balance; }

        }

        public void Credit(decimal amount)

        {

            _balance += amount;

        }

        public void Debit(decimal amount)

        {

            if (_balance - amount < 0)

                throw new Exception("Insufficient fund available");

            _balance -= amount;

        }

    }

    public class EmployeeCollection : KeyedCollection

    {

        public EmployeeCollection()

            : base()

        {

        }

        protected override int GetKeyForItem(Employee emp)

        {

            return emp.EmployeeID;

        }

    }

    public class MonthlySummary

    {

        int _totalEmployeesReceivingSalary;

        decimal _totalMonthlySalary;

        decimal _totalMonthlyRecovery;

        public int TotalEmployeesReceivingSalary

        {

            get { return _totalEmployeesReceivingSalary; }

        }

        public decimal TotalMonthlySalary

        {

            get { return _totalMonthlySalary; }

        }

        public decimal TotalMonthlyRecovery

        {

            get { return _totalMonthlyRecovery; }

        }

        public void UpdateThisEmployeeDetails(Employee emp)

        {

            _totalEmployeesReceivingSalary += 1;

            _totalMonthlySalary += emp.SalaryTobePaid;

            _totalMonthlyRecovery += emp.SalaryTobePaid - emp.Salary;

        }

    }

    public class Employer

    {

        BankAccount _employerBankAccount;

        MonthlySummary _monthlySummary;

        public Employer()

        {

            _employerBankAccount = new BankAccount(100000000);

            _monthlySummary = new MonthlySummary();

        }

        public void PaySalary(Employee emp)

        {

            _employerBankAccount.Debit(emp.SalaryTobePaid);

            emp.CreditSalary();

            _monthlySummary.UpdateThisEmployeeDetails(emp);

        }

    }

Sample input file;
FirstName;LastName;Salary;AdvanceTaken;MonthlyDeduction;Tenure;AccountBalance
Raja;vel;10000;0;0;0;200000
Bal;ji;10000;0;0;0;100000
test;test;10000;100000;5000;20;10000

TDD using Moq

Recently I was experimenting TDD in C# using Moq mocking framework. An awesome mocking framework. Some samples are below;

For more details on Moq refer this link;
https://code.google.com/p/moq/

[TestMethod]
        public void TestEnrollCustomer()
        {
            var enrollment = new Mock(MockBehavior.Strict, MockCustomerDetails.One);
            bool actual = false;
              actual=  enrollment.Object.EnrollCustomer();
            Assert.AreEqual(true, actual, "Failed to execute");
        }

public class MockCustomerDetails
    {
        static CustomerDetails customer1 = null;
        static CustomerDetails customer2 = null;
        static CustomerDetails customer3 = null;
        static MockCustomerDetails()
        {
            customer1 = new CustomerDetails(MockCustomer.One, MockBIB.One, MockLockBox.One);
            customer2 = new CustomerDetails(MockCustomer.Two, MockBIB.Two, MockLockBox.Two);
            customer3 = new CustomerDetails(MockCustomer.Three, MockBIB.Three, MockLockBox.Three);
        }

        public static CustomerDetails One
        {
            get
            {
                return customer1;
            }
        }
        public static CustomerDetails Two
        {
            get
            {
                return customer2;
            }
        }
        public static CustomerDetails Three
        {
            get
            {
                return customer3;
            }
        }
    }

public class MockBIB
    {
        static DummyBIB bib1 = null;
        static DummyBIB bib2 = null;
        static DummyBIB bib3 = null;

        static MockBIB()
        {
            bib1 = new DummyBIB("1213121");
            bib2 = new DummyBIB("12131zcxc21");
            bib3 = new DummyBIB("12wewe13121");
        }
        public static DummyBIB One
        {
            get
            {
                return bib1;
            }
        }
        public static DummyBIB Two
        {
            get
            {
                return bib2;
            }
        }
        public static DummyBIB Three
        {
            get
            {
                return bib3;
            }
        }
    }

public class MockLockBox
    {
        static DummyLockBox lock1 = null;
        static DummyLockBox lock2 = null;
        static DummyLockBox lock3 = null;

        static MockLockBox()
        {
            lock1 = new DummyLockBox("1213121");
            lock2 = new DummyLockBox("121sdsad3121"); 
            lock3 = new DummyLockBox("1213wrtwrtrw121");
        }
        public static DummyLockBox One
        {
            get
            {
                return lock1;
            }
        }
        public static DummyLockBox Two
        {
            get
            {
                return lock2;
            }
        }
        public static DummyLockBox Three
        {
            get
            {
                return lock3;
            }
        }
    }

Dynamic XPATH in XSLT using C#

Recently I had a task of converting a flat XML to hierarchical XML deserializable to .NET entities. Everything was smooth until I got into a situation where-in I had some elements like shown below


...
<CCY1>GBP</CCY1>
<Value1>1.34</Value1>
<CCY2>EUR</CCY2>


<Value2>1.34</Value2>
...


which needed to be like after conversion as shown below


....
<CCYDetails>
<CCYDetail>
<CCY>GBP</CCY>
<Value>1.34</Value>
....
</CCYDetails>
</CCYDetail>
...
 
After some research in internet, I figured out that it is not straight forward in XSLT. It needs some help of scripting language. Since I am from .NET background, I wasn't able to find much help in this regard. Then I found one code in one of the forum threads and tweaked a bit to get it working.


XSLT
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:msxsl="urn:schemas-microsoft-com:xslt" exclude-result-prefixes="msxsl"
xmlns:user="http://tempuri.org/user">
<msxsl:script language="CSharp" implements-prefix="user">
<![CDATA[
public XPathNodeIterator FilterNodes(XPathNodeIterator context,string xpath)
{
context.MoveNext();
return context.Current.Select(xpath);
}
]]>
</msxsl:script>
<xsl:template match="/">
<root>
<CCYDetailss>
<xsl:for-each select="MinPayInAmendment">
<xsl:call-template name="ccy_loop">
</xsl:call-template>
</xsl:for-each>
</CCYDetails>
</root>
</xsl:template>
<xsl:template name="ccy_loop">
<xsl:param name="num">1</xsl:param>
<xsl:if test="not ($num=17)">
<xsl:variable name="ccy" select="concat('CCY',$num)">
</xsl:variable>
<xsl:variable name="new" select="concat('New',$num)">
</xsl:variable>
<CCYDetail>
<CCY>
<xsl:value-of select="user:FilterNodes(.,$ccy)"/>
</CCY>
<New>
<xsl:value-of select="user:FilterNodes(.,$new)"/>
</New>
</CCYDetail>
<xsl:call-template name="ccy_loop">
<xsl:with-param name="num">
<xsl:value-of select="$num+1"></xsl:value-of>
</xsl:with-param>
</xsl:call-template>
</xsl:if>
</xsl:template>
</xsl:stylesheet>


C#
XPathDocument xpath = new XPathDocument(@"C:\input_xml.xml");

XPathNavigator navi = xpath.CreateNavigator();
XsltSettings settings = new XsltSettings();
settings.EnableScript = true;
settings.EnableDocumentFunction = true;
XslCompiledTransform transform = new XslCompiledTransform();
transform.Load(@"C:\XSLTFile1.xslt",settings,new XmlUrlResolver());
MemoryStream resultStream = new MemoryStream();
XmlWriterSettings writer_settings = new XmlWriterSettings();
writer_settings.Indent = true;
XmlWriter writer = XmlWriter.Create(resultStream,writer_settings);
transform.Transform(xpath, null, writer);
resultStream.Position = 0;
StreamReader stream = new StreamReader(resultStream);
Console.WriteLine(stream.ReadToEnd());
writer.Close();

PDF to XML using iTextsharp

Here is the very simple way of creating the XML from PDF document. I used Form fields in the PDF document. Then using the iTextsharp, I looped through the Acrofields or Form fields and created the flat XML document out of it. You can customize to create more complex structures if need be.

XmlDocument doc = new XmlDocument();
PdfReader reader = new PdfReader(@"C:\Input.pdf");
AcroFields fields = reader.AcroFields;
doc.LoadXml(string.Format("<{0}/>", root));
foreach (string keyName in fields.Fields.Keys)
{
AcroFields.Item item = fields.GetFieldItem(keyName);
XmlElement elt = doc.CreateElement(keyName);
elt.InnerXml = "<![CDATA[" + fields.GetField(keyName) + "]]>"";
doc.DocumentElement.AppendChild(elt);
}
doc.Save(@"C:\output.xml");

EntityFramework and WCF

Recently while developing the WCF wrapper service for Entity Framework figured out that, the entities from EF cannot be used over the Channel. The reason was "The ObjectContext instance has been disposed and can no longer be used for operations that require a connection". [You can capture this error if you enable WCF diagnostic logging].

There is a work around for this. You will have to use Data Transfer objects which mirror the entities from EF. So you can use those DTOs for tranmitting over the channel. It is not necessary that you will have to do this process manually, there are small add-ins available for doing this job. I used the EntitiesToDTO codeplex VS2010 add-in for this. So whenever we update the EF entities, just re-run this add-in which will update the DTOs based on the entities from EF.

PS - The transformation from entities to DTOs still need to be done by ourselves in the WCF operations.

Getting OperationContract name in WCF MessageDispatcher

There may be times where you need to identify the OperationContract name in WCF MessageDispatcher and do some processing based on that. Here is how you can do that;

In case of WCF Endpoint

In the AfterReceiveRequest method, do the following to get the Operation name;

MessageBuffer buffer = request.CreateBufferedCopy(Int32.MaxValue);

Message originalMessage = buffer.CreateMessage();

XmlDictionaryReader xmlDict = orginialMessage.GetReaderAtBodyContents();

XmlDocument doc = new XmlDocument();

doc.LoadXml(xmlDict.ReadOuterXml());

string action = doc.DocumentElement.Name; //here you will get the OperationContract name

In case of WCF REST Endpoint

In the AfterReceiveRequest method, do the following to get the Operation name;

MessageProperties props = request.Properties;
string action = props["HttpOperationName"].ToString(); //here you will get the OperationContract name

WCF DataContract serialization and deserialization in Silverlight

Here is how you can do serialization and deserialization of WCF DataContracts in Silverlight. This is needed when you use MessageContracts in WCF by wrapping DataContracts as XmlElement.

Serialization code:

DataContractSerializer serialize = new DataContractSerializer(request.GetType());
MemoryStream stream = new MemoryStream();
serializer.WriteObject(stream,request);
string res = Encoding.UTF8.GetString(stream.ToArray(),0,stream.ToArray().GetLength(0));
TextReader reader = new StringReader(res);
XDocument doc = XDocument.Load(reader);
XElement elt = (XElement)doc.FirstNode;

you can pass the elt in your MessageContract and send to the WCF service.

Deserialization code:

Once you receive the response from WCF service as XElement, this is how you can deserialize that to object.

XmlDictionaryReader reader = XmlDictionaryReader.CreateDictionaryReader(elt.CreateReader());
DataContractSerializer serialize = new DataContractSerializer(reader);
result - serialize.ReadObject(reader);

Code to capture the Message arrived event in Outlook

There may be times when we want to do some operation upon arrival of the message in the Outlook Inbox. Here is the simple piece of code which will help to capture the message arrived event in Outlook.

//Initialization code
protected override bool DoInitialise()
{
outlook = new ApplicationClass();
outlook.Session.Logon(null, null, false, false);
inbox = outlook.Session.GetDefaultFolder(OlDefaultFolders.olFolderInbox).Items;
inbox.ItemAdd += new ItemsEvents_ItemAddEventHandler(inbox_ItemAdd);
outlook.NewMailEx += new ApplicationEvents_11_NewMailExEventHandler(outlook_NewMailEx);
return true;
}


void outlook_NewMailEx(string EntryIDCollection)
{
//This event will be fired whenever a mail arrives in Inbox
}

Passing Default Credentials from Silverlight to WCF

While developing Silverlight and WCF apps you will have to share the default credentials from Silverlight to WCF service sometime.



This is how you can do;


1) Create the <basicHttpBinding> with the following information under the <bindings> section;

<basicHttpBinding>
<binding name="BasicBinding0">
<security mode="TransportCredentialOnly">
<transport clientCredentialType="Windows"/>
</security>
</binding>
</basicHttpBinding>

2) Add the below piece of section under the <System.ServiceModel> section
<serviceHostingEnvironment aspNetCompatibilityEnabled="true">
</serviceHostingEnvironment>

3) Add the below piece of code above the OperationContract behavior;
[System.ServiceModel.Activation.AspNetCompatibilityRequirements(RequirementsMode=System.ServiceModel.Activation.AspNetCompatibilityRequirementsMode.Allowed)]
public class StaticDataProcessing : ProcessTaskWCFBase

Please note that steps 2 and 3 are needed to avoid the HttpContext.Current coming as NULL issue.

This way you can pass the default credentials from Silverlight to WCF.

Issues With Programmatically Attaching Multiple Files To A List Item

Recently one of my team member was facing issue while adding multiple files to a list item programmatically. The issue was, about 10% files added programmatically were corrupt while uploading. So whenever the user tries to download the file, they were getting "HTTP 500 Internal Server". Below is the piece of code he was using;

HttpFileCollection uploads = HttpContext.Current.Request.Files;


for (int i = 0; i < uploads.Count; i++)

{


HttpPostedFile upload = uploads[i];


if (upload.ContentLength == 0)


continue;


Stream inputStream = upload.InputStream;


byte[] buffer = new byte[inputStream.Length];


inputStream.Read(buffer, 0, (int)inputStream.Length);


inputStream.Close();


eItem.Attachments.Add(upload.FileName, buffer);


}


eItem.Update();
 
On analysing we found out that, the issue was with Attachments.Add method. It was causing some corruptions in the bytes uploaded. So we tried with Attachments.AddNow..
Bingo!!! It started to work without any issues.
 
The only difference between "Attachments.Add" and "Attachments.AddNow" was, "Attachments.AddNow"; it will create new version whenever you attach.
Also, "Attachments.AddNow" internally calls the "Update" method of the List Item. Though its very weird, it is solving the problem of bytes corruption while uploading multiple attachments to the list item.

Search a text in all properties of an object in collection (FullTextSearch) using LINQ

Recently in our project, we had a requirement to search for particular character in the List. The search is similar to FullTextSearch which means, we need to search for a specific character in each and every property of an object contained in the list..
We initial thought the only way is to use LINQ to add condition for every property with OR statement. Then while googling got one idea from this link;
http://manfred-ramoser.blogspot.com/2009/09/full-text-search-for-entity-framework.html

This exactly does the same what we needed except failed in one scenario. (i.e.) this failed when any of the property is NULL. So I modified the code a little bit which take cares of the NULL situation as well. Below is that code;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Linq.Expressions;
using System.Reflection;


namespace TestXML
{
public static class QuerableExtensionMethods
{
public static IQueryable<T> FullTextSearch<T>(this IQueryable<T> querytable, string searchkey)
{
return FullTextSearch<T>(querytable.AsQueryable<T>(), searchkey, false);
}


public static IQueryable<T> FullTextSearch<T>(this IQueryable<T> querytable, string searchkey,bool exactMatch)
{


ParameterExpression parameter = Expression.Parameter(typeof(T), "c");
ParameterExpression stringParameter = Expression.Parameter(typeof(string), "d");
MethodInfo containsMethod = typeof(string).GetMethod("Contains", new Type[] { typeof(string) });
MethodInfo nullMethod = typeof(string).GetMethod("IsNullOrEmpty", new Type[] { typeof(string) });
var publicProperties = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly).Where(p => p.PropertyType == typeof(string));
Expression orExpression = null;


string[] searchKeyParts = null;


if (exactMatch)
searchKeyParts = new[] { searchkey };
else
searchKeyParts = searchkey.Split(' ');


foreach (var property in publicProperties)
{
Expression nameProperty = Expression.Property(parameter, property);
foreach (var searchKeyPart in searchKeyParts)
{


Expression searchkeyExpression = Expression.Constant(searchKeyPart);
Expression nullCheckExpression = Expression.Constant(null);
Expression callContainsMethod = Expression.Call(nameProperty, containsMethod, searchkeyExpression);
Expression nullCheckMethod = Expression.Call(stringParameter, nullMethod, nameProperty);
Expression notExpression = Expression.Not(nullCheckMethod);


if (orExpression == null)
orExpression = Expression.AndAlso(notExpression, callContainsMethod);
else
orExpression = Expression.Or(orExpression, Expression.AndAlso(notExpression, callContainsMethod));
}
}
MethodCallExpression whereCallExpression = Expression.Call(typeof(Queryable), "Where", new Type[] { querytable.ElementType }, querytable.Expression,
Expression.Lambda<Func<T, bool>>(orExpression, new ParameterExpression[] { parameter }));


return querytable.Provider.CreateQuery<T>(whereCallExpression);
}


}
}

Happy coding and wishing all the viewers of my blog happy and prosperous new year!!!!