Microsoft Dot Net Master

Tuesday, May 24, 2016

Difference between WCF,Web API,WCF REST and Web Service

Thee .Net framework has a number of technologies that allow you to create HTTP services such as Web Service, WCF and now Web API. There are a lot of articles over the internet which may describe to whom you should use. Now a days, you have a lot of choices to build HTTP services on .NET framework. In this article, I would like to share my opinion with you over Web Service, WCF and now Web API.

Web Service

It is based on SOAP and return data in XML form.
It support only HTTP protocol.
It is not open source but can be consumed by any client that understands xml.
It can be hosted only on IIS.

WCF

It is also based on SOAP and return data in XML form.
It is the evolution of the web service(ASMX) and support various protocols like TCP, HTTP, HTTPS, Named Pipes, MSMQ.
The main issue with WCF is, its tedious and extensive configuration.
It is not open source but can be consumed by any client that understands xml.
It can be hosted with in the applicaion or on IIS or using window service.

WCF Rest

To use WCF as WCF Rest service you have to enable webHttpBindings.
It support HTTP GET and POST verbs by [WebGet] and [WebInvoke] attributes respectively.
To enable other HTTP verbs you have to do some configuration in IIS to accept request of that particular verb on .svc files
Passing data through parameters using a WebGet needs configuration. The UriTemplate must be specified
It support XML, JSON and ATOM data format.

Web API

This is the new framework for building HTTP services with easy and simple way.
Web API is open source an ideal platform for building REST-ful services over the .NET Framework.
Unlike WCF Rest service, it use the full featues of HTTP (like URIs, request/response headers, caching, versioning, various content formats)
It also supports the MVC features such as routing, controllers, action results, filter, model binders, IOC container or dependency injection, unit testing that makes it more simple and robust.
It can be hosted with in the application or on IIS.
It is light weight architecture and good for devices which have limited bandwidth like smart phones.
Responses are formatted by Web API’s MediaTypeFormatter into JSON, XML or whatever format you want to add as a MediaTypeFormatter.

To whom choose between WCF or WEB API

Choose WCF when you want to create a service that should support special scenarios such as one way messaging, message queues, duplex communication etc.
Choose WCF when you want to create a service that can use fast transport channels when available, such as TCP, Named Pipes, or maybe even UDP (in WCF 4.5), and you also want to support HTTP when all other transport channels are unavailable.
Choose Web API when you want to create a resource-oriented services over HTTP that can use the full features of HTTP (like URIs, request/response headers, caching, versioning, various content formats).
Choose Web API when you want to expose your service to a broad range of clients including browsers, mobiles, iphone and tablets.

Sunday, April 24, 2016

What is an application server?

As defined in Wikipedia, an application server is a software engine that delivers applications to client computers or devices. The application server runs your server code. Some well known application servers are IIS (Microsoft), WebLogic Server (BEA), JBoss (Red Hat), WebSphere (IBM).

ASP.NET - Life Cycle

ASP.NET life cycle specifies, how:

ASP.NET processes pages to produce dynamic output
The application and its pages are instantiated and processed
ASP.NET compiles the pages dynamically

The ASP.NET life cycle could be divided into two groups:

Application Life Cycle
Page Life Cycle

ASP.NET Application Life Cycle

The application life cycle has the following stages:

User makes a request for accessing application resource, a page. Browser sends this request to the web server.
A unified pipeline receives the first request and the following events take place:
- An object of the class ApplicationManager is created.
- An object of the class HostingEnvironment is created to provide information regarding the resources.
- Top level items in the application are compiled.
Response objects are created. The application objects such as HttpContext, HttpRequest and HttpResponse are created and initialized.
An instance of the HttpApplication object is created and assigned to the request.
The request is processed by the HttpApplication class. Different events are raised by this class for processing the request.

ASP.NET Page Life Cycle

When a page is requested, it is loaded into the server memory, processed, and sent to the browser. Then it is unloaded from the memory. At each of these steps, methods and events are available, which could be overridden according to the need of the application. In other words, you can write your own code to override the default code.

The Page class creates a hierarchical tree of all the controls on the page. All the components on the page, except the directives, are part of this control tree. You can see the control tree by adding trace= "true" to the page directive. We will cover page directives and tracing under 'directives' and 'event handling'.

The page life cycle phases are:

Initialization
Instantiation of the controls on the page
Restoration and maintenance of the state
Execution of the event handler codes
Page rendering

Understanding the page cycle helps in writing codes for making some specific thing happen at any stage of the page life cycle. It also helps in writing custom controls and initializing them at right time, populate their properties with view-state data and run control behavior code.

Following are the different stages of an ASP.NET page:

Page request - When ASP.NET gets a page request, it decides whether to parse and compile the page, or there would be a cached version of the page; accordingly the response is sent.
Starting of page life cycle - At this stage, the Request and Response objects are set. If the request is an old request or post back, the IsPostBack property of the page is set to true. The UICulture property of the page is also set.
Page initialization - At this stage, the controls on the page are assigned unique ID by setting the UniqueID property and the themes are applied. For a new request, postback data is loaded and the control properties are restored to the view-state values.
Page load - At this stage, control properties are set using the view state and control state values.
Validation - Validate method of the validation control is called and on its successful execution, the IsValid property of the page is set to true.
Postback event handling - If the request is a postback (old request), the related event handler is invoked.
Page rendering - At this stage, view state for the page and all controls are saved. The page calls the Render method for each control and the output of rendering is written to the OutputStream class of the Response property of page.
Unload - The rendered page is sent to the client and page properties, such as Response and Request, are unloaded and all cleanup done.

ASP.NET Page Life Cycle Events

At each stage of the page life cycle, the page raises some events, which could be coded. An event handler is basically a function or subroutine, bound to the event, using declarative attributes such as Onclick or handle.

Following are the page life cycle events:

PreInit - PreInit is the first event in page life cycle. It checks the IsPostBack property and determines whether the page is a postback. It sets the themes and master pages, creates dynamic controls, and gets and sets profile property values. This event can be handled by overloading the OnPreInit method or creating a Page_PreInit handler.
Init - Init event initializes the control property and the control tree is built. This event can be handled by overloading the OnInit method or creating a Page_Init handler.
InitComplete - InitComplete event allows tracking of view state. All the controls turn on view-state tracking.
LoadViewState - LoadViewState event allows loading view state information into the controls.
LoadPostData - During this phase, the contents of all the input fields are defined with the <form> tag are processed.
PreLoad - PreLoad occurs before the post back data is loaded in the controls. This event can be handled by overloading the OnPreLoad method or creating a Page_PreLoad handler.
Load - The Load event is raised for the page first and then recursively for all child controls. The controls in the control tree are created. This event can be handled by overloading the OnLoad method or creating a Page_Load handler.
LoadComplete - The loading process is completed, control event handlers are run, and page validation takes place. This event can be handled by overloading the OnLoadComplete method or creating a Page_LoadComplete handler
PreRender - The PreRender event occurs just before the output is rendered. By handling this event, pages and controls can perform any updates before the output is rendered.
PreRenderComplete - As the PreRender event is recursively fired for all child controls, this event ensures the completion of the pre-rendering phase.
SaveStateComplete - State of control on the page is saved. Personalization, control state and view state information is saved. The HTML markup is generated. This stage can be handled by overriding the Render method or creating a Page_Render handler.
UnLoad - The UnLoad phase is the last phase of the page life cycle. It raises the UnLoad event for all controls recursively and lastly for the page itself. Final cleanup is done and all resources and references, such as database connections, are freed. This event can be handled by modifying the OnUnLoad method or creating a Page_UnLoad handler.

Wednesday, December 30, 2015

Bootstrap Button Groups

In this tutorial you will learn how to use Bootstrap button group component.

Creating Button Group with Bootstrap

In the previous chapter you've learnt how to create different types of individual buttons and modify them with predefined classes. Bootstrap however, also allows you to group a series of buttons together in a single line through the button group component.

To create a button groups just wrap a series of buttons in a <div> element and apply the class .btn-group on it, like shown in the example below:

Example

```
<div class="btn-group">
```

    <button type="button" class="btn btn-primary">Left</button>

    <button type="button" class="btn btn-primary">Middle</button>

    <button type="button" class="btn btn-primary">Right</button>

```
</div>
```

— The output of the above example will look something like this:

You can also make the button groups appear vertically stacked rather than horizontally. To do this just replace the class .btn-group with the .btn-group-vertical.

Example

```
<div class="btn-group-vertical">
```

    <button type="button" class="btn btn-primary">Top</button>

    <button type="button" class="btn btn-primary">Middle</button>

    <button type="button" class="btn btn-primary">Bottom</button>

```
</div>
```

Creating Button Toolbar

You can also combine sets of button groups together for creating more complex components like button toolbar. To create button toolbar just wrap sets of button groups in a <div>element and apply the class .btn-toolbar on it.

Example

```
<div class="btn-toolbar">
```
```
    <div class="btn-group">
```

        <button type="button" class="btn btn-primary">1</button>

        <button type="button" class="btn btn-primary">2</button>

        <button type="button" class="btn btn-primary">3</button>

        <button type="button" class="btn btn-primary">4</button>

```
    </div>
```
```
    <div class="btn-group">
```

        <button type="button" class="btn btn-primary">5</button>

        <button type="button" class="btn btn-primary">6</button>

        <button type="button" class="btn btn-primary">7</button>

```
    </div>
```
```
    <div class="btn-group">
```

        <button type="button" class="btn btn-primary">8</button>

```
    </div>
```
```
</div>
```

— The output of the above example will look something like this:

Height Sizing of Button Groups

You can also apply relative sizing classes like .btn-group-lg, .btn-group-sm or .btn-group-xs on button groups to create larger or smaller button groups. Just add these button sizing classes directly to the .btn-group, instead of applying to every button.

Example

```
<div class="btn-toolbar">
```

    <div class="btn-group btn-group-lg">

        <button type="button" class="btn btn-primary">Left</button>

        <button type="button" class="btn btn-primary">Middle</button>

        <button type="button" class="btn btn-primary">Right</button>

```
    </div>
```
```
</div>
```
```
<div class="btn-toolbar">
```
```
    <div class="btn-group">
```

        <button type="button" class="btn btn-primary">Left</button>

        <button type="button" class="btn btn-primary">Middle</button>

        <button type="button" class="btn btn-primary">Right</button>

```
    </div>
```
```
</div>
```
```
<div class="btn-toolbar">
```

    <div class="btn-group btn-group-sm">

        <button type="button" class="btn btn-primary">Left</button>

        <button type="button" class="btn btn-primary">Middle</button>

        <button type="button" class="btn btn-primary">Right</button>

```
    </div>
```
```
</div>
```
```
<div class="btn-toolbar">
```

    <div class="btn-group btn-group-xs">

        <button type="button" class="btn btn-primary">Left</button>

        <button type="button" class="btn btn-primary">Middle</button>

        <button type="button" class="btn btn-primary">Right</button>

```
    </div>
```
```
</div>
```

— The output of the above example will look something like this:

Creating Justified Button Groups

You can also make a group of buttons stretch at the same size to span the entire width of its parent by appling an extra class .btn-group-justified to the .btn-group base class.

The following example will create a justified button group using the <a> element.

Example

<div class="btn-group btn-group-justified">

    <a href="#" class="btn btn-primary">Left</a>

    <a href="#" class="btn btn-primary">Middle</a>

    <a href="#" class="btn btn-primary">Right</a>

```
</div>
```

— The output of the above example will look something like this:

However, to create justified button groups using the <button> elements, you must wrap each button individually in a .btn-group class, otherwise it will not work.

Example

<div class="btn-group btn-group-justified">

```
    <div class="btn-group">
```

        <button type="button" class="btn btn-primary">Left</button>

```
    </div>
```
```
    <div class="btn-group">
```

        <button type="button" class="btn btn-primary">Middle</button>

```
    </div>
```
```
    <div class="btn-group">
```

        <button type="button" class="btn btn-primary">Right</button>

```
    </div>
```
```
</div>
```

The story doesn't ends here; in the advanced section you'll learn how createbutton dropdowns as well as stateful buttons through activating the toggling and loading state on simple buttons and the button groups component.