Getting started with Raspberry Pi

Raspberry Pi is a small, low powered motherboard contains 512 RAM, combined CPU and GPU. It has LAN, 2 USB, HDMI input, Audio Out, SD Card reader and S-Video connectors.

We can have many Linux distribution OS on it. To configure, we just need to attach SD Card to it. SD Card could range from class 4 to class 10. In some cases Raspberry Pi could support less then class 4 cards too. It could be powered through mini USB mobile charger.

Let's get started with installing OS on SD Card. There are various ways to install OS. Like we can download OSes through http://www.raspberrypi.org/downloads and follow the instructions given on it. There is something BerryBoot multi-boot loader through which we can have more then one OS on Raspberry Pi and boot OS according to our need. http://www.berryterminal.com/doku.php/berryboot instructions could be followed to install OS with very simple steps. You need to have internet connection on Raspberry Pi to install OS. It could be done by connecting through LAN or some Raspberry PI WiFi dongle.

Give it a try to Raspbian wheezy and XBMC OS. Raspbian wheezy is similar to any other Linux distribution OS. Through XBMC we can convert normal TV into smart TV or can have HTPC. It is able to play Full HD video and also it could be controlled through mobiles, slates or some TV remotes. XMBC is having tons of features through it's various add-ons.

Handling JSON DateTime format on Asp.Net Core

This is a very simple trick to handle JSON date format on AspNet Core by global settings. This can be applicable for the older version as well.

In a newer version by default, .Net depends upon Newtonsoft to process any JSON data. Newtonsoft depends upon Newtonsoft.Json.Converters.IsoDateTimeConverter class for processing date which in turns adds timezone for JSON data format.

There is a global setting available for same that can be adjusted according to requirement. So, for example, we want to set default formatting to US format, we just need this code.

services.AddMvc() .AddJsonOptions(options => { options.SerializerSettings.DateTimeZoneHandling = "MM/dd/yyyy HH:mm:ss"; });

Elegantly dealing with TimeZones in MVC Core / WebApi

In any new application handling TimeZone/DateTime is mostly least priority and generally, if someone is concerned then it would be handled by using DateTime.UtcNow on codes while creating current dates and converting incoming Date to UTC to save on servers.
Basically, the process is followed by saving DateTime to UTC format in a database and keep converting data to native format based on user region or single region in the application's presentation layer.
The above is tedious work and have to be followed religiously. If any developer misses out the manual conversion, then that area of code/view would not work.
With newer frameworks, there are flexible ways to deal/intercept incoming or outgoing calls to simplify conversion of TimeZones.
These are steps/process to achieve it. 1. Central code for storing user's state about TimeZone. Also, central code for conversion logic based on TimeZones. 2. Dependency injection for the above class to be able to use globally. 3. Creating Mo…

Architecture solution composting Repository Pattern, Unit Of Work, Dependency Injection, Factory Pattern and others

Project architecture is like garden, we plant the things in certain order and eventually they grow in similar manner. If things are planted well then they will all look(work) great and easier to manage. If they grow as cumbersome it would difficult to maintain and with time more problems would be happening in maintenance.

There is no any fixed or known approach to decide project architecture and specially with Agile Methodology. In Agile Methodology, we cannot predict how our end products will look like similarly we cannot say a certain architecture will fit well for entire development lifespan for project. So, the best thing is to modify the architecture as per our application growth. I understand that it sounds good but will be far more problematic with actual development. If it is left as it is then more problems will arise with time. Just think about moving plant vs a full grown tree.

Coming to technical side, In this article, I will be explaining about the various techniques tha…

LDAP with ASP.Net Identity Core in MVC with project.json

Lightweight Directory Access Protocol (LDAP), the name itself explain it. An application protocol used over an IP network to access the distributed directory information service.

The first and foremost thing is to add references for consuming LDAP. This has to be done by adding reference from Global Assembly Cache (GAC) into project.json

"frameworks": { "net461": { "frameworkAssemblies": { "System.DirectoryServices": "4.0.0.0", "System.DirectoryServices.AccountManagement": "4.0.0.0" } } },
These System.DirectoryServices and System.DirectoryServices.AccountManagement references are used to consume LDAP functionality.

It is always better to have an abstraction for irrelevant items in consuming part. For an example, the application does not need to know about PrincipalContext or any other dependent items from those two references to make it extensible. So, we can begin with some bas…

Trim text in MVC Core through Model Binder

Trimming text can be done on client side codes, but I believe it is most suitable on MVC Model Binder since it would be at one place on infrastructure level which would be free from any manual intervention of developer. This would allow every post request to be processed and converted to a trimmed string.

Let us start by creating Model binder

using Microsoft.AspNetCore.Mvc.ModelBinding; using System; using System.Threading.Tasks; public class TrimmingModelBinder : IModelBinder { private readonly IModelBinder FallbackBinder; public TrimmingModelBinder(IModelBinder fallbackBinder) { FallbackBinder = fallbackBinder ?? throw new ArgumentNullException(nameof(fallbackBinder)); } public Task BindModelAsync(ModelBindingContext bindingContext) { if (bindingContext == null) { throw new ArgumentNullException(nameof(bindingContext)); } var valueProviderResult = bindingContext.ValueProvider.GetValue(bindingC…

Unit Of Work injection through Asp.Net Core Dependency Injection

This article is not directly related to UnitOfWork but leveraging Asp.Net Core Dependency Injection to consume Unit Of Work.

In one of the previous article about project architecture, I was not very satisfied with the approach for Unit Of Work implementation for initialization of repository even if with some advantage.

Here is old code for UnitOfWork.

public sealed partial class MyProjectUnitOfWork : UnitOfWork<DbContext>, IMyProjectUnitOfWork { public MyProjectUnitOfWork(IContextFactory<DbContext> contextFactory) : base(contextFactory) { } /// <summary> /// BookRepository holder /// </summary> private MyProject.DB.Repository.BookRepository _bookRepository; /// <summary> /// Gets the BookRepository repository. /// </summary> /// <value> /// The BookRepository repository. /// </value> MyProject.Interface.Repository.IBoo…

Making FluentValidation compatible with Swagger including Enum or fixed List support

FluentValidation is not directly compatible with Swagger API to validate models. But they do provide an interface through which we can compose Swagger validation manually. That means we look under FluentValidation validators and compose Swagger validator properties to make it compatible. More of all mapping by reading information from FluentValidation and setting it to Swagger Model Schema.
These can be done on any custom validation from FluentValidation too just that proper schema property has to be available from Swagger.
Custom validation from Enum/List values on FluentValidation using FluentValidation.Validators; using System.Collections.Generic; using System.Linq; using static System.String; /// <summary> /// Validator as per list of items. /// </summary> /// <seealso cref="PropertyValidator" /> public class FixedListValidator : PropertyValidator { /// <summary> /// Gets the valid items /// </sum…

Kendo MVC Grid DataSourceRequest with AutoMapper - Advance

The actual process to make DataSourceRequest compatible with AutoMapper was explained in my previous post Kendo MVC Grid DataSourceRequest with AutoMapper, where we had created custom model binder attribute and in that property names were changed as data models.

In this post we will be looking into using AutoMapper's Queryable extension to retrieve the results based on selected columns. When Mapper.Map<RoleViewModel>(data) is called it retrieves all column values from table. The Queryable extension provides a way to retrieve only selected columns from table. In this particular case based on properties of RoleViewModel.
The previous approach that we implemented is perfect as far as this article (3 Tips for Using Telerik Data Access and AutoMapper) is concern about performance where it states: While this functionality allows you avoid writing explicit projection in to your LINQ query it has the same fatal flaw as doing so - it prevents the query result from being cached.
Since …

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jQuery Datatable generic implementation on .Net/dotnet Core for any entity server filtering or sorting through EF/EF Core

August 31, 2017

jQuery Datatable is one of the popular freely available grid for the developers. It works really great on the client side but there is always need to write a lot of codes on the server side for filtering and sorting for each individual entities.

In this article, we would address this by creating a generic implementation of server code which can work on any entity without writing any further piece of code for filtering and sorting. Just by calling a generic extension method it would resolve sorting and filtering.

The key points to achieve it are as follows:
- Model binding and provider to transform client side request to strongly typed item on the server.
- Once we get strongly typed items to read values, we can apply a dynamic approach to generate queries and filters through LINQ expression.
- At final part, just consumption of created mechanism by creating endpoints for each entity. Also, we can easily select required columns through LINQ projection.
Model Binding As per DataTable ser…

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T4, Generating interface automatically based on provided classes

March 29, 2015

With new techniques and patterns interface plays a key role in application architecture. Interface makes application extendable like defining file upload interface and implementing based on file system, Azure Blob storage, Amazon S3. At starting we might be implementing based on Azure Blob but later we might move to Windows based file system and so on.

Ideally we create interface based on need and start implementing actual default implementation class. Many a times at starting of implementation there is one to one mapping between Interface and Class. Like from above example File upload interface and the initial or default class implementation that we design and with time it will get extended.
In this article, we will try to create interface based on default class implementation. This is not at all recommended in Test Driven Design (TDD) where we test the application before actual code implementation but I feel sometimes and in some situations it is okay do that and test straight afte…

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