Imagine I have a class like this:
public class BaseRepo<T> where T : class
{
private readonly DbSet<T> table;
public BaseRepo(MyDbContext context)
{
this.table = context.Set<T>();
}
}
I want to implement the following logic in to this class.
string GenerateUniqueStringFor(PropertyName)
{
string val = string.Empty;
do
{
val = GenerateRandomString();
}
while (this.table.FirstOrDefault(x => x.PropertyName == val) is not null);
return val;
}
The problem is I don't know how to pass Property/PropertyName. The ideal way for calling it would be:
string val = _myRepo.GenerateUniqueStringFor(x => x.PropertyName);
If I understand correctly, you can try to pass a delegate Func
string GenerateUniqueStringFor(Func<T,string> func)
{
string val = string.Empty;
do
{
val = GenerateRandomString();
}
while (this.table.FirstOrDefault(x => func(x) == val) is not null);
return val;
}
Related
In short I wanted to create a custom IUserType to represent IPAddress from .NET (as an inet type in postgresql) and to be able to query it with custom functions via HQL and Linq. I have trouble with implementing a custom function for Linq.
What I have thus far:
A) I am able to map it:
public class SomeEntityMapper : ClassMap<SomeEntity> {
public SomeEntityMapper() {
...
Map(x => x.IpAddressField)
.CustomSqlType("inet")
.CustomType<IPAddressUserType>()
...
}
}
IUserType implementation below:
[Serializable]
public class IPAddressUserType : IUserType
{
public new bool Equals(object x, object y)
{
if (x == null && y == null)
return true;
if (x == null || y == null)
return false;
return x.Equals(y);
}
public int GetHashCode(object x)
{
if (x == null)
return 0;
return x.GetHashCode();
}
public object NullSafeGet(DbDataReader rs, string[] names, ISessionImplementor session, object owner)
{
if (names.Length == 0)
throw new InvalidOperationException("Expected at least 1 column");
if (rs.IsDBNull(rs.GetOrdinal(names[0])))
return null;
object value = rs[names[0]];
return value;
}
public void NullSafeSet(DbCommand cmd, object value, int index, ISessionImplementor session)
{
NpgsqlParameter parameter = (NpgsqlParameter) cmd.Parameters[index];
parameter.NpgsqlDbType = NpgsqlTypes.NpgsqlDbType.Inet;
if (value == null)
{
parameter.Value = DBNull.Value;
}
else
{
parameter.Value = value;
}
}
public object DeepCopy(object value)
{
if (value == null)
return null;
IPAddress copy = IPAddress.Parse(value.ToString());
return copy;
}
public object Replace(object original, object target, object owner)
{
return original;
}
public object Assemble(object cached, object owner)
{
if (cached == null)
return null;
if (IPAddress.TryParse((string)cached, out var address))
{
return address;
}
return null;
}
public object Disassemble(object value)
{
if (value == null)
return null;
return value.ToString();
}
public SqlType[] SqlTypes => new SqlType[] { new NpgsqlSqlType(DbType.String, NpgsqlTypes.NpgsqlDbType.Inet), };
public Type ReturnedType => typeof(IPAddress);
public bool IsMutable => false;
}
public class NpgsqlSqlType : SqlType
{
public NpgsqlDbType NpgDbType { get; }
public NpgsqlSqlType(DbType dbType, NpgsqlDbType npgDbType)
: base(dbType)
{
NpgDbType = npgDbType;
}
public NpgsqlSqlType(DbType dbType, NpgsqlDbType npgDbType, int length)
: base(dbType, length)
{
NpgDbType = npgDbType;
}
public NpgsqlSqlType(DbType dbType, NpgsqlDbType npgDbType, byte precision, byte scale)
: base(dbType, precision, scale)
{
NpgDbType = npgDbType;
}
}
}
B) I am able to query it using HQL and a custom function (inet_equals) I implemented.
using(var session = _factory.OpenSession()) {
var q = session.CreateQuery("from SomeEntity as s WHERE inet_equals(s.IpAddressField, :ip)");
q.SetParameter("ip", IPAddress.Parse("4.3.2.1"), NHibernateUtil.Custom(typeof(IPAddressUserType)));
}
Custom Postgresql Dialect extending the HQL functions implementation below:
public class CustomPostgresqlDialect : PostgreSQL83Dialect
{
public CustomPostgresqlDialect()
{
RegisterFunction("inet_equals", new SQLFunctionTemplate(NHibernateUtil.Boolean, "(?1::inet = ?2::inet)"));
}
}
C) I want to be able to query it using LINQ like so:
using(var session = _factory.OpenSession()) {
var q = session.Query<SomeEntity>()
.Where(s => s.IpAddressField.InetEquals(IPAddress.Parse("4.3.2.1")));
}
Custom LINQ Generator for NHibernate provider below:
public static class InetExtensions
{
public static bool InetEquals(this IPAddress value, IPAddress other)
{
throw new NotSupportedException();
}
}
public class InetGenerator : BaseHqlGeneratorForMethod
{
public InetGenerator()
{
SupportedMethods = new[]
{
ReflectHelper.GetMethodDefinition(() => InetExtensions.InetEquals(default(IPAddress), default(IPAddress)))
};
}
public override HqlTreeNode BuildHql(MethodInfo method, System.Linq.Expressions.Expression targetObject, ReadOnlyCollection<System.Linq.Expressions.Expression> arguments,
HqlTreeBuilder treeBuilder, IHqlExpressionVisitor visitor)
{
HqlExpression lhs = visitor.Visit(arguments[0]).AsExpression();
HqlExpression rhs = visitor.Visit(arguments[1]).AsExpression();
return treeBuilder.BooleanMethodCall(
"inet_equals",
new[]
{
lhs,
rhs
}
);
}
}
public class ExtendedLinqToHqlGeneratorsRegistry :
DefaultLinqToHqlGeneratorsRegistry
{
public ExtendedLinqToHqlGeneratorsRegistry()
: base()
{
this.Merge(new InetGenerator());
}
}
Unfortunately when using LINQ I get this exception:
HibernateException: Could not determine a type for class: System.Net.IPAddress
Interestingly, this is the exact same error I get if I omit the NHibernateUtil.Custom(typeof(IPAddressUserType)) parameter inside the HQL query.
Which leads me to believe I am on the right track, but I can't figure out what I may be missing exactly. I assume I need to inform NHibernate inside the Generator that this is a custom UserType (just like I did with the HQL query via the NHibernateUtil.Custom(typeof(IPAddressUserType)) parameter.
I found the solution.
To hint NHibernate to use the proper UserType use: MappedAs extension method, like so:
using(var session = _factory.OpenSession()) {
var q = session.Query<SomeEntity>()
.Where(s => s.IpAddressField.InetEquals(
IPAddress.Parse("4.3.2.1").MappedAs(NHibernateUtil.Custom(typeof(IPAddressUserType))
);
}
The year is 2019 and I'm still stuck on version 3.3.2.GA of NHibernate and the MappedAs extension method exists only on version 4.x onwards.
My scenario was the need to pass a large string as a parameter to a supported method in an HqlGeneratorForMethod.
I created the following class to store any large string to use as a parameter of any method throughout the application:
public class StringClob
{
public StringClob()
{
}
public StringClob(string value)
{
Value = value;
}
public virtual string Value { get; protected set; }
}
In order to link the NHibernateUtil.StringClob type with the string value I had the idea to create a mapping for my class without informing table mapping just the property (I use FluentNHibernate to map class):
public class StringClobMap : ClassMap<StringClob>
{
public StringClobMap()
{
Id(x => x.Value, "VALUE").CustomType("StringClob").CustomSqlType("VARCHAR(MAX)").Length(int.MaxValue / 2);
}
}
And now hypothetically following the example of #krdx the usage would look like this:
using(var session = _factory.OpenSession())
{
var q = session.Query<SomeEntity>()
.Where(s => s.IpAddressField.InetEquals(new StringClob("<large_string_here>")));
// ...
}
Therefore by passing the StringClob class as a parameter, NHibernate gets the custom type defined in the mapping.
I hope I helped those who still use NHibernate 3.3.2.GA.
I have an abstract class like this:
public abstract class Records
{
public string Type;
public string Source;
public int Value;
protected Records(string type, string source, int value)
{
Type = type;
Source = source;
Value = value;
}
}
I would like to create many classes inheriting this class, and filling their Type field with a value coming from a static class like this:
public static class ContentTypesString
{
public static string DocumentNew { get { return "Document - New this Month"; }}
public static string HeadlinesNew { get { return "Headlines - New this Month"; }}
etc...
}
I would like to be able to create those child classes without having a test "if foo == "document" then type = ContentTypesString.DocumentNew" or an equivalent switch case (I really have a lot of cases)
Is there a design pattern that suits my needs?
EDIT : As several people pointed out, i should show how i create my instances.
private delegate SPListItemCollection Query(SPWeb web, DateTime startDate, DateTime endDate);
private readonly Query _queries;
#region Constructors
public QueryHandler(SPWeb web, DateTime startTimeSelectedDate, DateTime endTimeSelectedDate)
{
if (web == null) throw new ArgumentNullException("web");
_web = web;
_startTimeSelectedDate = startTimeSelectedDate;
_endTimeSelectedDate = endTimeSelectedDate;
RecordsList = new List<Records>();
// Query Invocation List
_queries = NumberPagePerMonthQuery.PreparedQuery;
_queries += NumberDocumentsPerMonthQuery.PreparedQuery;
_queries += NumberHeadlinesPerMonthQuery.PreparedQuery;
_queries += NumberLeaderboxPerMonthQuery.PreparedQuery;
_queries += NumberNewsPerMonthQuery.PreparedQuery;
_queries += NumberPagesModifiedPerMonthQuery.PreparedQuery;
_queries += NumberPicturesPerMonthQuery.PreparedQuery;
_queries += NumberTeasingPerMonthQuery.PreparedQuery;
}
#endregion Constructors
#region Public Methods
// what about NullReferenceException ? C#6 : item?.Foreach(item => {}); ?
/*** NO C#6 compiler in VS2012... ***/
public void Queries()
{
foreach (var del in _queries.GetInvocationList())
{
var queryresult =
(SPListItemCollection) del.DynamicInvoke(_web, _startTimeSelectedDate, _endTimeSelectedDate);
RecordsList.Add(new Records(del.Method.Name, _web.Title, queryresult.Count));
}
}
EDIT² :
The solution i chose
public List<IQuery> QueryList { get; } // no delegate anymore, and static classes became implementations of IQuery interface.
#region Constructors
public QueryHandler(SPWeb web, DateTime startTimeSelectedDate, DateTime endTimeSelectedDate)
{
if (web == null) throw new ArgumentNullException("web");
_web = web;
_startTimeSelectedDate = startTimeSelectedDate;
_endTimeSelectedDate = endTimeSelectedDate;
RecordsList = new List<Records>();
QueryList = new List<IQuery>
{
new NumberDocumentsPerMonthQuery(),
new NumberHeadlinesPerMonthQuery(),
new NumberLeaderboxPerMonthQuery(),
new NumberNewsPerMonthQuery(),
new NumberPagePerMonthQuery(),
new NumberPagesModifiedPerMonthQuery(),
new NumberPicturesPerMonthQuery(),
new NumberTeasingPerMonthQuery()
};
}
#endregion Constructors
#region Public Methods
// what about NullReferenceException ? C#6 : item?.Foreach(item => {}); ?
/*** NO C#6 compiler in VS2012... ***/
public void Queries()
{
foreach (var query in QueryList)
{
var queryresult = query.PreparedQuery(_web, _startTimeSelectedDate, _endTimeSelectedDate);
RecordsList.Add(query.CreateRecord(_web.Title, queryresult.Count));
}
}
Record class follow the implementation suggested by #dbraillon
Implementation of IQuery interface were added the method :
public Records CreateRecord(string source, int value)
{
return new ModifiedPagesPerMonthRecord(source, value); //or another child of Record class.
}
And voilà. Thank you all for the help.
You want to make collection of records, by string code of object type, and parameters.
One of many way to do it - use builder.
Firstly we need to configurate builder:
var builder = new RecordBuilder()
.RegisterBuilder("document", (source, value) => new Document(source, value))
.RegisterBuilder("headlines", (source, value) => new Headlines(source, value));
here we specify how to build record with code "document" and "headlines".
To build a record call:
builder.Build("document", "source", 1);
Builder code can by something like this
(here we look if we know how to build record of the passed type and make it):
public class RecordBuilder
{
public Records Build(string code, string source, int value)
{
Func<string, int, Records> buildAction;
if (recordBuilders.TryGetValue(code, out buildAction))
{
return buildAction(source, value);
}
return null;
}
public RecordBuilder RegisterBuilder(string code, Func<string, int, Records> buildAction)
{
recordBuilders.Add(code, buildAction);
return this;
}
private Dictionary<string, Func<string, int, Records>> recordBuilders = new Dictionary<string, Func<string, int, Records>> ();
}
public class Document : Records
{
public Document(string source, int value) : base(ContentTypesString.DocumentNew, source, value)
{
}
}
public class Headlines : Records
{
public Headlines(string source, int value) : base(ContentTypesString.HeadlinesNew, source, value)
{
}
}
Is that what you need ?
public abstract class Records
{
public string Type;
public string Source;
public int Value;
protected Records(string type, string source, int value)
{
Type = type;
Source = source;
Value = value;
}
}
public class DocumentRecords : Records
{
public DocumentRecords(string source, int value)
: base(ContentTypesString.DocumentNew, source, value) // use here
{
}
}
public class HeadlinesRecords : Records
{
public HeadlinesRecords(string source, int value)
: base(ContentTypesString.HeadlinesNew, source, value) // use here
{
}
}
public static class ContentTypesString
{
public static string DocumentNew { get { return "Document - New this Month"; } }
public static string HeadlinesNew { get { return "Headlines - New this Month"; } }
}
I'm trying to understand a way to pass in two or more extension methods to a another method as parameters and return the value back. I have extension methods for each datatype to return a value or default value and a value or a null value and also a value or throw an error. The code has scenarios that would require each of these, but it also has scenarios combining the results from each of these in a ternary test, examples below.
public static int IntOrError(this object val, string fieldName)
{
int test;
if (string.IsNullOrEmpty(val.ToString()))
{
throw new Exception("I threw it");
}
else if (int.TryParse(val.ToString(), out test) == false)
{
throw new Exception("Bad Int Value");
}
else
{
return test;
}
}
public static int IntOrDefault(this object val)
{
int test;
if (int.TryParse(val.ToString(), out test))
{
return test;
}
else
{
return -1;
}
}
public static int? IntOrNull(this object val)
{
int test;
if (int.TryParse(val.ToString(), out test))
{
return test;
}
else
{
return -1;
}
}
I've been trying to make a reusable method that could process taking in in this example IntOrNull, IntOrDefault and IntOrError and pass back the int or throw an error. So far I've only been able to get this to work. I'm trying to avoid creating this method for every datatype also.
public static int IntDefaultValidated(this object val, string fieldName)
{
return val.IntOrNUll() != null
? val.IntOrDefaultError(fieldName)
: val.IntOrDefault();
}
I am trying to get a generic method or a functional style of method that will take in the extension methods as params and return back the value.
I'm hoping to avoid reflection if possible.
//just a psuedo example
var intVal = "";
var valRet = DefaultValidated(intVal.IntOrNull(), intVal.IntOrdefault(), intVal.IntOrDefaultError("intVal"));
//or maybe like this, or some combination of extension, generic, functional
var valRet = intVal.DefaultOrValidated(IntOrNull(intVal), IntOrDefault(intVal), IntOrDefaultError(intVal, "intVal"));
Your logic of IntOrDefault, IntOrNull and IntDefaultValidated does not really make sense, so I think it's just an usage example.
Beside this - my advice is to implement your functions as generic extensions.
public static class MyExtensions
{
public static T ValueOrError<T>(this object val)
{
try
{
// http://stackoverflow.com/a/8633/2534462
return (T)Convert.ChangeType(val, typeof(T));
} catch
{
throw new Exception("Throw your own exception if you really want to");
}
}
public static T ValueOrDefault<T>(this object val, T defaultValue)
{
try
{
return val.ValueOrError<T>();
}
catch
{
return defaultValue; // usally use: return default(T);
}
}
public static T ValueOrNull<T>(this object val)
{
try
{
return val.ValueOrError<T>();
}
catch
{
// check for nullable type
//https://msdn.microsoft.com/de-de/library/ms366789.aspx
var type = typeof(T);
if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>))
{
return default(T); // null on nullable types
} else {
throw new Exception("Callable only on Nullable types");
// my return another default value ??? .. -1 ???
}
}
}
public static T ValueDefaultValidated<T>(this object val, T defaultValue)
{
return val.ValueOrNull<T>() != null
? val.ValueOrError<T>()
: val.ValueOrDefault<T>(defaultValue);
}
}
Usage
string aNumber = "10";
var intNumber = aNumber.ValueDefaultValidated(-1); // int
var decNumber = aNumber.ValueDefaultValidated(-1m); // decimal
string naNumber = "whatever";
var defaultInt = naNumber.ValueOrDefault(-1); // int
var defaultDecimal = naNumber.ValueDefaultValidated<decimal?>(-1m);
// ValueOrNull ist undefined on Non-Nullable-Type.
var undefined = naNumber.ValueDefaultValidated<decimal>(-1m);
Something like this?
public static T Convert<T>(this object input)
{
if (typeof (T) == input.GetType())
return (T) input;
var stringValue = input.ToString();
var converter = TypeDescriptor.GetConverter(typeof(T));
if (converter.CanConvertFrom(typeof(string)))
{
return (T)converter.ConvertFrom(stringValue);
}
return default(T);
}
This test passes. May be this is not exactly what you need but still.
[Fact]
public void TestMethod1()
{
object testInt = 1;
object testString = "123";
double testDouble = 1.0;
string testWrong = "abc";
int resultInt = testInt.Convert<int>();
string resultString = testString.Convert<string>();
int resultIntString = testString.Convert<int>();
int dbl2int = testDouble.Convert<int>();
Assert.Throws<Exception>(() => testWrong.Convert<int>());
Assert.Equal(1, resultInt);
Assert.Equal("123", resultString);
Assert.Equal(123, resultIntString);
Assert.Equal(1, dbl2int);
}
Apologies for the amount of code, but it is easier to explain it this way.
I have a custom attribute CustomUserData implemented as follows:
public class CustomUserData : Attribute
{
public CustomUserData(object aUserData)
{
UserData = aUserData;
}
public object UserData { get; set; }
}
and an extension method for enums as:
public static class EnumExtensions
{
public static TAttribute GetAttribute<TAttribute>(this Enum aValue) where TAttribute : Attribute
{
Type type = aValue.GetType();
string name = Enum.GetName(type, aValue);
return type.GetField(name)
.GetCustomAttributes(false)
.OfType<TAttribute>()
.SingleOrDefault();
}
public static object GetCustomUserData(this Enum aValue)
{
CustomUserData userValue = GetAttribute<CustomUserData>(aValue);
return userValue != null ? userValue.UserData : null;
}
}
I then have a helper class that serializes/deserializes an enum that has custom data associated with it as follows:
public static class ParameterDisplayModeEnumListHelper
{
public static List<ParameterDisplayModeEnum> FromDatabase(string aDisplayModeString)
{
//Default behaviour
List<ParameterDisplayModeEnum> result = new List<ParameterDisplayModeEnum>();
//Split the string list into a list of strings
List<string> listOfDisplayModes = new List<string>(aDisplayModeString.Split(','));
//Iterate the enum looking for matches in the list
foreach (ParameterDisplayModeEnum displayModeEnum in Enum.GetValues(typeof (ParameterDisplayModeEnum)))
{
if (listOfDisplayModes.FindIndex(item => item == (string)displayModeEnum.GetCustomUserData()) >= 0)
{
result.Add(displayModeEnum);
}
}
return result;
}
public static string ToDatabase(List<ParameterDisplayModeEnum> aDisplayModeList)
{
string result = string.Empty;
foreach (ParameterDisplayModeEnum listItem in aDisplayModeList)
{
if (result != string.Empty)
result += ",";
result += listItem.GetCustomUserData();
}
return result;
}
}
however this is specific to ParameterDisplayModeEnum and I have a bunch of enums that I need to treat this way for serialization/deserialization so I would prefer to have a generic such as:
public static class EnumListHelper<TEnum>
{
public static List<TEnum> FromDatabase(string aDisplayModeString)
{
//Default behaviour
List<TEnum> result = new List<TEnum>();
//Split the string list into a list of strings
List<string> listOfDisplayModes = new List<string>(aDisplayModeString.Split(','));
//Iterate the enum looking for matches in the list
foreach (TEnum displayModeEnum in Enum.GetValues(typeof (TEnum)))
{
if (listOfDisplayModes.FindIndex(item => item == (string)displayModeEnum.GetCustomUserData()) >= 0)
{
result.Add(displayModeEnum);
}
}
return result;
}
public static string ToDatabase(List<TEnum> aDisplayModeList)
{
string result = string.Empty;
foreach (TEnum listItem in aDisplayModeList)
{
if (result != string.Empty)
result += ",";
result += listItem.GetCustomUserData();
}
return result;
}
}
However this will not work as GetCustomUserData() cannot be invoked. Any suggestions? I cannot change the use of the custom attribute or the use of the enums. I am looking for a generic way to do the serialization/deserialization without having to write a concrete list helper class each time.
All suggestions appreciated.
Try this code:
public static class EnumListHelper
{
private static void EnsureIsEnum<TEnum>()
{
if (!typeof(TEnum).IsEnum)
throw new InvalidOperationException(string.Format("The {0} type is not an enum.", typeof(TEnum)));
}
public static List<TEnum> FromDatabase<TEnum>(string aDisplayModeString)
where TEnum : struct
{
EnsureIsEnum<TEnum>();
//Default behaviour
List<TEnum> result = new List<TEnum>();
//Split the string list into a list of strings
List<string> listOfDisplayModes = new List<string>(aDisplayModeString.Split(','));
//Iterate the enum looking for matches in the list
foreach (Enum displayModeEnum in Enum.GetValues(typeof(TEnum)))
{
if (listOfDisplayModes.FindIndex(item => item == (string)displayModeEnum.GetCustomUserData()) >= 0)
{
result.Add((TEnum)(object)displayModeEnum);
}
}
return result;
}
public static string ToDatabase<TEnum>(List<TEnum> aDisplayModeList)
where TEnum : struct
{
EnsureIsEnum<TEnum>();
string result = string.Empty;
foreach (var listItem in aDisplayModeList.OfType<Enum>())
{
if (result != string.Empty)
result += ",";
result += listItem.GetCustomUserData();
}
return result;
}
}
var fromDatabase = EnumListHelper.FromDatabase<TestEnum>("test");
EnumListHelper.ToDatabase(fromDatabase);
UPDATE 0
To be clear, because we cannot restrict generics to Enum we should check that the type TEnum is an enum and throw an exception if it is not.
When we use the FromDatabase method we know that TEnum is enum, and we can write this code to cast an enum to the specified TEnum:
result.Add((TEnum)(object)displayModeEnum)
in the ToDatabase method we also know that TEnum is enum and we can write this code to convert TEnum to the Enum type:
aDisplayModeList.OfType<Enum>()
Ideally you'd want to restrict TEnum to Enum but that won't work as you can not restrict generics to Enum MicrosoftBut try following, it might do the trick...
if (listOfDisplayModes.FindIndex(item =>
item == (string)(displayModeEnum as Enum).GetCustomUserData()) >= 0)
I have a method as under
private int SaveRecord(PartnerViewLog partnerViewLog, PortalConstant.DataSourceType DataSourceType, Func<IDataAccess, PartnerViewLog, int> chooseSelector)
{
int results = -1;
var dataPlugin = DataPlugins.FirstOrDefault(i => i.Metadata["SQLMetaData"].ToString() == DataSourceType.EnumToString());
if (dataPlugin != null)
{
results = chooseSelector(dataPlugin.Value, partnerViewLog);
}
return results;
}
I am invoking it as under
public int SavePartnerViewLog(PartnerViewLog partnerViewLog, PortalConstant.DataSourceType DataSourceType)
{
return SaveRecord(partnerViewLog, DataSourceType, (i, u) => i.SavePartnerViewLog(partnerViewLog));
}
As can be figured out that PartnerViewLog is a class. Now I want to make the function SaveRecord as generic where the class name can be anything?
How to do so?
Try the following:
private int SaveRecord<T>(T record, PortalConstant.DataSourceType dataSourceType, Func<IDataAccess, T, int> chooseSelector)
{
int results = -1;
var dataPlugin = DataPlugins.FirstOrDefault(i => i.Metadata["SQLMetaData"].ToString() == dataSourceType.EnumToString());
if (dataPlugin != null)
{
results = chooseSelector(dataPlugin.Value, record);
}
return results;
}
private int SaveRecord<T>(T partnerViewLog, PortalConstant.DataSourceType dataSourceType, Func<IDataAccess, T, int> chooseSelector)
{
...
}
Every thing else remains the same