Sessions

Question 1

What is a session?

Answer 1

The user interaction when the user opens a browser, does some tasks and closes the browser is called a session.

For example, when the user opens a browser, logs in, then adds some products, checkout and closes the browser. This is called a session.

Question 2

Explain “HTTP is a stateless protocol” ?

Answer 2

HTTP does not remember states between the request and the response. User sends the request, server processes it and responds. When a user sends another request in the same session, the server consider it as a new request.

For example, create a member variable, i, in the controller class. Increment this in any action method, this won’t be persisted in next request.

Question 3

What are various way of doing session management ?

OR

How do you maintain states in HTTP request?

Answer 3

There are three ways:

Tempdata

Viewdata/ViewBag

Sessions variables

Question 4

Are sessions enabled by default ?

Answer 4

No.

Question 5

How to enable sessions in MVC core ?

Answer 5

In ConfigureServices, add

servcies. AddSession( options = >
options. idleTImeut = TimeSpan.Minutes(15));

in Configure methods,

app.UseSession()

To read a session, HTTPContext.Session.GetString(“name”);

to set,

HTTPContext.Session.SetString(“name”, “value”);

Question 6

Are sessions variables shared(global) between users ?

Answer 6

No

Question 7

Do session variables use cookies ?

Answer 7

Yes

Question 8

What is a cookie ?

Answer 8

They are small text files that stored in the end userss’ machines.

Question 9

Explain idle time out in sessions ? ….

Answer 9

servcies. AddSession( options = >

options. idleTImeut = TimeSpan.Minutes(15));

Question 10

What does a Context means in HTTP ?

Answer 10

one request and response is called a context. HTTPContext holds information regarding sessions, request data and response information. It has all data required for one request and response.

Question 11

When should we use viewdata ?

How to pass data from controller to view ? .

Answer 11

use viewData

in controller action method

{
Viewdata[“vd”] = 5
}

In the HTML file use

@ViewData[“vd”]

Question 12

In same request can viewdata persist across actions ?

Answer 12

No…

Question 13

ViewBag vs ViewData ?

Answer 13

ViewBag is a synthetic sugar to ViewData.

ViewData[“vd”] = ViewBag.vd

Question 14

How does ViewBag work internally ?

Answer 14

it uses dynamic and if viewbag’s property is not existing then it returns null.

Question 15

ViewBag vs ViewModel Whats the best practice ?

Answer 15

use strongly types such as ViewModel

Question 16

What is ViewModel?

Answer 16

to create a ViewModel, create a class called

ViewModelClass
{

}

Populate its data in the Action method.

Then in the view, @model modelname

@Model.properties

Question 17

Explain tempdata ?

Answer 17

tbd

Question 18

How is tempdata different from viewdata ?

Answer 18

ViewData is not persist from action to action and accross requests. in tempdata we can control its persistence.

Question 19

If tempdata is read is it available for next request ?

Answer 19

Value ispersist accross request until it it read

Question 20

How to persist tempdata ?
or
What does Keep do in tempdata ?…

Answer 20

use Keep method. Keep don’t return anything.

Question 21

Explain Peek in tempdata ?

Answer 21

read + Keep is Peek

Question 22

How is tempdata different from session variables ?

Answer 22

Session vairble stays until the entire session

Question 23

How is tempdata different from session variables ?

Answer 23

Session variables stays until the entire session

Question 24

Is tempdata private to a user ?.

Answer 24

yes

Question 25

ViewData vs ViewBag vs Tempdata vs Session variables

Answer 25

TBD