DOT NET ACADEMY

Development Practices Notes (RAW & Incomplete)

noreply@blogger.com (Dr. Rajesh Rolen) — Sun, 12 Apr 2020 10:19:00 +0000

Why Care About Code Quality?
We wanna be agile, what is agile means? Agile means we gonna get the feedback from customer/PM and based on that feedback, we go back and respond to those changes. So that in the next PM meeting we can say that here are the changes, you wanted us to do last time, so review it and then we can move forward.

AS sitting there with the customers and asking them what kind of change you need to make, you begin to realize that the particular change they want to make, if you were going to make, you will have to touch that peace of code, u remember the one that I am talking about, right? That peace of the code that u touch last time and u could not go home that weekend. U gonna quietly tell the customer, u know that’s not a good chance after all, because u don’t wanna spend yet another weekend at work.
So in another word, one of the main reasons to care about code quality is as simple as that u cannot be agile if your code sucks, so it's important for us to care about code quality. It doesn’t mean that just because you have the quality of code, u are agile, I am not saying that, right? I am saying that it will become really hard to be agile if your code sucks.

Abelson & Sussman talk about his in their book, in the SICP book (Structure and Interpretation of Computer Programs),” programs must be written for people to read, and only incidentally for machines to execute”, so we all write code and we focus so much on writing code, so more than writing code, me must make sure that our code is readable, so now, why is this important for us to read someone’s code in our team? And the reason is, we write code just once but we have to maintain it continuously, and if we not gonna maintain the code then what is the point in writing that. And any code u write has to be maintained if somebody tells u that they

Code Reviews
Pair programming
Never get code reviewed by the non-programming person (manager or architect)
If managers are not doing programming then they can give more time to dev-testing and wiki documentation for functionality.
Beware of ticket only managers
Use UML Diagram in Architecture Design.
Appreciate person in CR and Arc meeting if he has done a good job.
1 to 1 meeting.
Don’t Interrogate
Don’t interview
Add many good points also
Ask for his problems (even if it's personal, it will help in building a good relationship)
BDD & TDD
Never show every task very urgent or critical (it will reduce the criticality of original critical tickets)
Never show your junior’s work on your name
Assign someone’s work to others just because the main person will come late… this will double to analysis time and will interrupt the other also
Variable names must be greater than two characters
Never apply lots of reporting tools and other monitoring on developers; it will end up in reducing performance instead.

We all write code and we focus so much on writing code but more the writing code we must make sure that we are writing readable codes.
Now, why is that important to write the readable codes? And the reason is, we write code only once but we have to maintain it continuously.
If somebody tells you that they wrote the code once and they never changed the design or code. What they are telling is, the project/feature is canceled.

How to write readable code?
Just write the code and give it to somebody to read it. And this is really important because even the original programmer has left the company, your code will still remain readable. It will reduce the maintenance time as well as, there will be no need to remember the code, as code is readable, it can be changed easily even after years. It is a kind of code review also.
You can fix the issue in non-readable code immediately after the code, maybe even after 3-4 days.. but later even after 3 weeks. If you try to fix the issue then you will have to first understand the whole scenario again. And what will happen, if you get the request to change the code after the year.
So we must write the code in such a readable form, so that it can be fixed by anyone in the team.
How to detect defects and how to reduce the defect (not talking about fixing the defect): adding features during development is 100 times cheaper than doing changes in the maintenance.

40-50% of maintenance code is an avoidable rework
90% of the downtime of the projects comes for 10% code, bugs.
Never reintroduce the defects. Resolve the defect in a way that it should never come back with bugs. So you can save the re-fixing time
Code reviews and unit tests both are very important but code reviews have much more impact on the quality of product compare to unit tests.
As Code reviews make sure that your code is readable. As another mind reads your code and if that finds any issue in it, it will reject the code review.
Its extremely important that who is doing code review, now in your organization if only programmers write code and so-called architect or managers review the code. It is a very dangerous situation.

The code reviewer should be a fellow programmer who is writing code with you, in the same team.
Such as non-coding architect and dev. managers are very dangerous for application if they are allowed to do code reviews
While doing a review, the reviewer must make sure the code has proper test coverage, it has written all required unit tests.
Disciplined practice can reduce the introduction of bugs and increase the quality of code.
We are not saying that discipline reduces defects, we are saying discipline reduces defect introduction.
We can see most of the company saying that we don’t have time to do it, we need to do it now, ASAP but they always have time to redo it. Programmers tell that we need the time or it going to take time and managers force that no we don’t have time, we need to fix it by today only, within a few hours. Then developers do the mesh and finish the work at the end of the day. But then what happens, that fast & furious code will be converted into multiple bugs and will take 20 times more time for bug fixing than it would have taken in initial development.

People are making the same mistake again and again and expecting different results. To get a different result you will have to do the change, and meetings are not called change. An introduction of the new meeting will consume more time and things will go more bed instead of going positive.
Technical Debt: people take shortcuts during critical immediate issues and leave a few things in between knowingly. We must clear such technical debts ASAP.
Technical debt is not a wrong thing but resolving those technical debts is the issue. You must schedule the time to fix the technical debts. It must be part of your work and schedule. A dedicated time for fixing technical debts will increase the quality of code as well as reduce the upcoming defects and defect introductions.
Technical debts are just like your credit card, you do the shopping and when it’s time to pay, you just pay the minimum amount and continue doing shopping. After doing the same for continually for a few months you will reach to a place where u won’t be able to pay it and you will become bank corrupt. Same this is with technical debt, people keep doing it and once it goes beyond their limit, they silently switch the track/job and leave that tech debt for other people.
Freezing of the requirements: many people use this term that we have frozen the requirement but the real term is “We

Features from MVC2 vs MVC3 vs MVC4 vs MVC5 vs MVC6

noreply@blogger.com (Dr. Rajesh Rolen) — Sat, 15 Sep 2018 07:56:00 +0000

MVC 2

Customer Side Validation
Templated Helpers
Regions
Nonconcurrent Controllers
Html.ValidationSummary Helper Method
DefaultValueAttribute in real life Method Parameters
Restricting Binary Data with Model Binders
DataAnnotations Attributes
Demonstrate Validator Providers
New RequireHttpsAttribute Action Filter
Templated Helpers
Show Model-Level Errors

MVC 3

Razor
Readymade venture formats
HTML 5 empowered formats
Support for Multiple View Engines
JavaScript and Ajax
Demonstrate Validation Improvements

MVC 4

ASP.NET Web API
Revived and modernized default venture formats
New versatile venture format
Numerous new highlights to help portable applications
Upgraded bolster for nonconcurrent techniques

MVC 5

One ASP.NET
Trait based directing
Asp.Net Identity
Bootstrap in the MVC layout
Confirmation Filters
Channel supersedes

MVC 6

ASP.NET MVC and Web API has been converged in to one.
Reliance infusion is inbuilt and part of MVC.
Next to each other - convey the runtime and structure with your application
Everything is bundled with NuGet, Including the .NET runtime itself.
New JSON based venture structure.
No compelling reason to recompile for each change. Simply hit space and revive the program.
Accumulation finished with the new Roslyn ongoing compiler.
vNext is Open Source by means of the .NET Foundation and is taking open commitments.
vNext (and Rosyln) additionally keeps running on Mono, on both Mac and Linux today.

Compiled By: Dr. Rajesh Rolen

Could Not Find 'Xamarin.iOS'

noreply@blogger.com (Dr. Rajesh Rolen) — Thu, 21 Apr 2016 10:33:00 +0000

Error: Could Not Find 'Xamarin.iOS'

You will get this error while building your xamarin ios/iphone/ipad project in visual studio.
To build ios apps in visual studio you need xamarin installed (at least xamarin.ios) on a mac machine in same network and link to that machine in visual studio.
you can link mac machine (xamarin installed on that) in visual studio from tools menu -> options
Compiled by: Dr. Rajesh Rolen

ASP.NET: failed to register url access denied

noreply@blogger.com (Dr. Rajesh Rolen) — Tue, 25 Aug 2015 07:00:00 +0000

to resolve the error : failed to register url access denied
Solution:
use window + R to open RUN
type below line in it and hit enter/run.
netsh http delete urlacl url=http://*:62940/

Cleans all views, SPS, functions PKs, FKs and tables

noreply@blogger.com (Dr. Rajesh Rolen) — Thu, 12 Mar 2015 13:27:00 +0000

/* Drop all non-system stored procs */
DECLARE @name VARCHAR(128)
DECLARE @SQL VARCHAR(254)

SELECT @name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'P' AND category = 0 ORDER BY [name])

WHILE @name is not null
BEGIN
    SELECT @SQL = 'DROP PROCEDURE [dbo].[' + RTRIM(@name) +']'
    EXEC (@SQL)
    PRINT 'Dropped Procedure: ' + @name
    SELECT @name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'P' AND category = 0 AND [name] > @name ORDER BY [name])
END
GO

/* Drop all views */
DECLARE @name VARCHAR(128)
DECLARE @SQL VARCHAR(254)

SELECT @name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'V' AND category = 0 ORDER BY [name])

WHILE @name IS NOT NULL
BEGIN
    SELECT @SQL = 'DROP VIEW [dbo].[' + RTRIM(@name) +']'
    EXEC (@SQL)
    PRINT 'Dropped View: ' + @name
    SELECT @name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'V' AND category = 0 AND [name] > @name ORDER BY [name])
END
GO

/* Drop all functions */
DECLARE @name VARCHAR(128)
DECLARE @SQL VARCHAR(254)

SELECT @name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] IN (N'FN', N'IF', N'TF', N'FS', N'FT') AND category = 0 ORDER BY [name])

WHILE @name IS NOT NULL
BEGIN
    SELECT @SQL = 'DROP FUNCTION [dbo].[' + RTRIM(@name) +']'
    EXEC (@SQL)
    PRINT 'Dropped Function: ' + @name
    SELECT @name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] IN (N'FN', N'IF', N'TF', N'FS', N'FT') AND category = 0 AND [name] > @name ORDER BY [name])
END
GO

/* Drop all Foreign Key constraints */
DECLARE @name VARCHAR(128)
DECLARE @constraint VARCHAR(254)
DECLARE @SQL VARCHAR(254)

SELECT @name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' ORDER BY TABLE_NAME)

WHILE @name is not null
BEGIN
    SELECT @constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' AND TABLE_NAME = @name ORDER BY CONSTRAINT_NAME)
    WHILE @constraint IS NOT NULL
    BEGIN
        SELECT @SQL = 'ALTER TABLE [dbo].[' + RTRIM(@name) +'] DROP CONSTRAINT [' + RTRIM(@constraint) +']'
        EXEC (@SQL)
        PRINT 'Dropped FK Constraint: ' + @constraint + ' on ' + @name
        SELECT @constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' AND CONSTRAINT_NAME <> @constraint AND TABLE_NAME = @name ORDER BY CONSTRAINT_NAME)
    END
SELECT @name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' ORDER BY TABLE_NAME)
END
GO

/* Drop all Primary Key constraints */
DECLARE @name VARCHAR(128)
DECLARE @constraint VARCHAR(254)
DECLARE @SQL VARCHAR(254)

SELECT @name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'PRIMARY KEY' ORDER BY TABLE_NAME)

WHILE @name IS NOT NULL
BEGIN
    SELECT @constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'PRIMARY KEY' AND TABLE_NAME = @name ORDER BY CONSTRAINT_NAME)
    WHILE @constraint is not null
    BEGIN
        SELECT @SQL = 'ALTER TABLE [dbo].[' + RTRIM(@name) +'] DROP CONSTRAINT [' + RTRIM(@constraint)+']'
        EXEC (@SQL)
        PRINT 'Dropped PK Constraint: ' + @constraint + ' on ' + @name
        SELECT @constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'PRIMARY KEY' AND CONSTRAINT_NAME <> @constraint AND TABLE_NAME = @name ORDER BY CONSTRAINT_NAME)
    END
SELECT @name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'PRIMARY KEY' ORDER BY TABLE_NAME)
END
GO

/* Drop all tables */
DECLARE @name VARCHAR(128)
DECLARE @SQL VARCHAR(254)

SELECT @name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'U' AND category = 0 ORDER BY [name])

WHILE @name IS NOT NULL
BEGIN
    SELECT @SQL = 'DROP TABLE [dbo].[' + RTRIM(@name) +']'
    EXEC (@SQL)
    PRINT 'Dropped Table: ' + @name
    SELECT @name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'U' AND category = 0 AND [name] > @name ORDER BY [name])
END
GO

'System.Linq.IQueryable' does not contain a definition for 'Include' and no extension method 'Include' accepting a first argument of type 'System.Linq.IQueryable' could be found

noreply@blogger.com (Dr. Rajesh Rolen) — Wed, 10 Dec 2014 08:00:00 +0000

Error: 'System.Linq.IQueryable' does not contain a definition for 'Include' and no extension method 'Include' accepting a first argument of type 'System.Linq.IQueryable' could be found

Solution: Add namespace System.Data.Entity;
Actually Include is not an extension method on Queryable, so it doesn't come with all the usual LINQ methods.
If you are using Entity Framework, you need to import namespace System.Data.Entity:

the type or namespace name 'expression' could not be found

noreply@blogger.com (Dr. Rajesh Rolen) — Wed, 10 Dec 2014 07:31:00 +0000

To remove error "the type or namespace name 'expression' could not be found" Add namespace System.Linq.Expressions. as normally System.Linq is there in using part by default and expression class is under system.Linq.Expressions so we have to make it also in using.

Best Practices for Code Review

noreply@blogger.com (Dr. Rajesh Rolen) — Fri, 07 Nov 2014 07:19:00 +0000

..http://support.smartbear.com/pdf/11_Best_Practices_for_Peer_Code_Review.pdf

The cast to value type 'Double' failed because the materialized value is null. Either the result type's generic parameter or the query must use a nullable type

noreply@blogger.com (Dr. Rajesh Rolen) — Fri, 07 Nov 2014 07:19:00 +0000

The cast to value type 'Double' failed because the materialized value is null. Either the result type's generic parameter or the query must use a nullable type OR The cast to value type 'Int32' failed because the materialized value is null. Either the result type's generic parameter or the query must use a nullable type Solution: Put conversion on values before putting it in functions like Avg, Sum etc like: In below code we have put conversion to decimal in average function.

var res =(from profile in dbModel.ProfileMasters
                                         select new
                                         {
                                             ProfileID = profile.ProfileId,
                                             Profile = profile.ClientName,
                                             Tasks= profile.TaskMasters.Count(),
                                             AverageTime = profile.TaskMasters.Select(x => EntityFunctions.DiffMinutes(x.StartTime, x.EndTime)).Average(y => (decimal?)y.Value),
                                             LastTime = profile.TaskMasters.Max(x=>x.StartTime)
                                         }).ToList();

DbArithmeticExpression arguments must have a numeric common type

noreply@blogger.com (Dr. Rajesh Rolen) — Fri, 07 Nov 2014 07:19:00 +0000

DbArithmeticExpression arguments must have a numeric common type Solution: we can't put datediff directly in linq / lambda.. instead of that we should use like : EntityFunctions.DiffMinutes Eg:

              dgvProfiles.DataSource = (from profile in dbModel.ProfileMasters
                                         select new
                                         {
                                             ProfileID = profile.ProfileId,
                                             Profile = profile.ClientName,
                                             Tasks= profile.TaskMasters.Count(),
                                             AverageTime = profile.TaskMasters.Select(x => EntityFunctions.DiffMinutes(x.StartTime, x.EndTime)).Average(y => (decimal?)y.Value),
                                             LastTime = profile.TaskMasters.Max(x=>x.StartTime)
                                         }).ToList();

The maximum message size quota for incoming messages (65536) has been exceeded

noreply@blogger.com (Dr. Rajesh Rolen) — Thu, 03 Apr 2014 07:51:00 +0000

System.ServiceModel.CommunicationException: The maximum message size quota for incoming messages (65536) has been exceeded. To increase the quota, use the MaxReceivedMessageSize property on the appropriate binding element. Just increase the MaxReceivedMessageSize if its in client (who is accessing wcf ) then got to app config and change that size like:

Change schema of all tables in database

noreply@blogger.com (Dr. Rajesh Rolen) — Wed, 26 Mar 2014 10:25:00 +0000

To change schema of any table/stored procedure you can use this command: ALTER SCHEMA NewSchemaName TRANSFER OldSchemaName.ObjectName But when you want to change schema of all table/sp of a database then its not a good idea to write such lines for all objects. better idea is to generate such script and then run it.. to generate such script for all tables, stored procedures and views, you can use below script.

SELECT 'ALTER SCHEMA NewSchemaName TRANSFER ' + SysSchemas.Name + '.' + DbObjects.Name + ';'
FROM sys.Objects DbObjects
INNER JOIN sys.Schemas SysSchemas ON DbObjects.schema_id = SysSchemas.schema_id
WHERE SysSchemas.Name = 'OldSchemaName'
AND (DbObjects.Type IN ('U', 'P', 'V'))

now just copy the output of this script and run...

Compiled by: Rajesh Rolen

Prevent addition of default paragraph tag by ckeditor

noreply@blogger.com (Dr. Rajesh Rolen) — Sat, 22 Mar 2014 13:07:00 +0000

to prevent addition of default paragraph tag

by ckeditor we have to add below lines in config.js

CKEDITOR.editorConfig = function (config) {
    config.enterMode = CKEDITOR.ENTER_BR;
    config.shiftEnterMode = CKEDITOR.ENTER_BR;

HTTP could not register URL . Your process does not have access rights to this namespace

noreply@blogger.com (Dr. Rajesh Rolen) — Thu, 13 Mar 2014 09:37:00 +0000

HTTP could not register URL http://+:8080/FileTranfer/.

Your process does not have access rights to this namespace (see http://go.microsoft.com/fwlink/?LinkId=70353 for details).

The issue is that the URL is being blocked from being created by Windows.

Steps to fix:
Run command prompt as an administrator.
Add the URL to the ACL netsh http add urlacl url=http://+:8080/FileTranfer/ user=mylocaluser

set entity framework connection string programmatically

noreply@blogger.com (Dr. Rajesh Rolen) — Sat, 22 Feb 2014 09:07:00 +0000

set entity framework connection string programmatically Error: Code generated using the T4 templates for Database First and Model First development may not work correctly if used in Code First mode. To continue using Database First or Model First ensure that the Entity Framework connection string is specified in the config file of executing application. To use these classes, that were generated from Database First or Model First, with Code First add any additional configuration using attributes or the DbModelBuilder API and then remove the code that throws this exception Solution:

   public static string GetConnectionString(ProfileMaster profile)
        {
            //return string.Format("data source={0};initial catalog={1};user id={2};password={3} multipleactiveresultsets=True;App=EntityFramework", profile.DatabaseIP, profile.DatabaseName, profile.UserName, profile.Password);
            string providerName = "System.Data.SqlClient";
            string serverName = profile.DatabaseIP;
            string databaseName = profile.DatabaseName;

            // Initialize the connection string builder for the
            // underlying provider.
            SqlConnectionStringBuilder sqlBuilder =
            new SqlConnectionStringBuilder();

            // Set the properties for the data source.
            sqlBuilder.DataSource = serverName;
            sqlBuilder.InitialCatalog = databaseName;
            sqlBuilder.IntegratedSecurity = true;

            // Build the SqlConnection connection string.
            string providerString = sqlBuilder.ToString();

            // Initialize the EntityConnectionStringBuilder.
            EntityConnectionStringBuilder entityBuilder =
            new EntityConnectionStringBuilder();

            //Set the provider name.
            entityBuilder.Provider = providerName;

            // Set the provider-specific connection string.
            entityBuilder.ProviderConnectionString = providerString;

            // Set the Metadata location.
            entityBuilder.Metadata = @"res://*/Models.MoviesDB.csdl|
                        res://*/Models.MoviesDB.ssdl|
                        res://*/Models.MoviesDB.msl";
            return entityBuilder.ToString();
        }

Compiled By: Rajesh Rolen

Debugging Dll

noreply@blogger.com (Dr. Rajesh Rolen) — Sat, 18 Jan 2014 20:13:00 +0000

System.Diagnostics.Debugger.Break();

Error for enumerable when using JsonConvert.SerializeObject

noreply@blogger.com (Dr. Rajesh Rolen) — Sat, 18 Jan 2014 20:13:00 +0000

[Serializable]
    public abstract class Entity
    {
        public Entity()
        {
        }

        public Entity(int id)
        {
            this.Id = id;
        }

        public virtual int Id { get; set; }

        public override bool Equals(object obj)
        {
            Entity other = (Entity)obj;
            return this.Id == other.Id;
        }

        public override int GetHashCode()
        {
            return this.Id.GetHashCode();
        }
    }

Observer Design Pattern in Jquery

noreply@blogger.com (Dr. Rajesh Rolen) — Sat, 18 Jan 2014 20:12:00 +0000

We can use observer design pattern (publisher - subscriber model) in jquery by triggering and attaching events.

Attach a trigger event for publisher
$('div').on('click', function(e) {
    $(this).trigger('MyEvent',e,parameterValue);
});


Attach subscriber methods
$(document).on('MyEvent', function(e,parameterValue) {
    //Do your stuffs with parameterValues..
});

Overwrite Appsetting in ASP.NET MVC

noreply@blogger.com (Dr. Rajesh Rolen) — Mon, 13 Jan 2014 14:57:00 +0000

  var config = WebConfigurationManager.OpenWebConfiguration("~");
  config.AppSettings.Settings["appSettingKey"].Value ="Updated value";
  config.Save(ConfigurationSaveMode.Minimal, false);
  ConfigurationManager.RefreshSection("appSettings");

MVC 3 Reload Partial View with Validations