c# – Page 7 – My Point of View

Hide/Show Div with javascript

To display and hide DIV in html;

<div class="card-body">
   <div id="divMessage">                
        @Html.Raw(@TempData["message"]);
    </div>
    </div>  
    <div> 
       <!--need to hide this form-->         
       <form method="post" asp-antiforgery="true" id="formDiv">
          <div class="card mb-3">
             <h5 class="card-header text-white">
                  Welcome To Div Hide/Display
             </h5>
        </form>
    </div>
</div>

Use this javascript;

@section Scripts
{
  <script>
     $(document).ready(function () {
            //show/hide login sections based on SSO
            divFormSection();
        });

        function divFormSection() {
            var isDivFormVisible = '@TempData["IsDivFormVisible"]';
            if (isDivFormVisible == 'false') {
                //alert(isDivFormVisible);
                $("#formDiv").hide();
            }
        }
     }
    </script>
}

We need to pass parameters from controller in TempData;

TempData["message"] = "Form Hide/Display demo";
TempData["IsDivFormVisible"] = "false";

Use TempData or ViewBag to render HTML

This is a very basic example;

Declare this in a controller.

var fontAwesomeIcon = "<span class=\"fa fa-redo\" style=\"font-size:30px; color: red; margin-bottom: 20px; \">&nbsp;Try again</span>";

TempData["message"] = $"{fontAwesomeIcon} <h5>Something went wrong. Please try again. If problem persist, reach out to your point of contact for additional information</h5>";

And you can use it in your view;

<div class="card-body">
  <div id="divMessage">
     @Html.Raw(@TempData["message"]);
  </div>
</div>

Return values from HttpContext.Current.User.Principal and WindowsIdentity.GetCurrent()

Here is a brief explanation;

According to this forum on WindowsIdentity.GetCurrent().Name vs. User.Identity.Name:

User.Identity.Name represents the identity passed from IIS.
WindowsIdentity.GetCurrent().Name is the identity under which the thread is running.

Depending on your app’s authentication settings in IIS, they will return different values:

`Anonymous`	`Impersonate`	`User.Identity.Name`	`WindowsIndentiy.GetCurrent()`
Yes	True	`Empty String`	`IUSR_<machineName>`
Yes	False	`Empty String`	`NT Authority\Network Service`
No	True	`domain\user`	`domain\user`
No	False	`domain\user`	`NT Authority\Network Service`

Legend:

Where domain\user will show up as:
- domain\user for Active Directory
- machineName\userName for local account
Where NT Authority\Network Service will show up as:
- NT Authority\Network Service for Windows Server or ASP.NET
- machineName\ASPNET_WP for Windows XP

Resource

https://stackoverflow.com/questions/5402249/httpcontext-current-user-principal-vs-windowsidentity-getcurrent

IEnumerable vs IQueryable

The IEnumerable and IQueryable are used to hold a collection of data and also used to perform data manipulation operations such as filtering, Ordering, Grouping, etc.

The main difference is this;

We can use SQL Profiler to confirm this behavior.

All about LINQ operators

A short list of LINQ operators.

Using IN clause

This is similar to database IN keyword;

var myInClause = new string[] {"One", "Two", "Three"};

var results = from x in MyTable
              where myInClause.Contains(x.SomeColumn)
              select x;
// OR
var results = MyTable.Where(x => myInClause.Contains(x.SomeColumn));

Using ALL operator

Working with simple types

//does all numbers are greater than 10
int[] IntArray = { 11, 22, 33, 44, 55 };
var Result = IntArray.All(x => x > 10);
Console.WriteLine("Is All Numbers are greater than 10 : " + Result);

//does all names has characters greater than three
string[] stringArray = { "Khan", "Ali", "Adam", "Eve", "Joe" };
Result = stringArray.All(name => name.Length > 3);
Console.WriteLine("Is All Names are greater than 3 Characters : " + Result);

var letterResult = stringArray.All(name => name.StartsWith("A"));
Console.WriteLine("Is All Names start with letter A : " + letterResult);

//all numbers can be divided by three
int[] numbers = { 3, 6, 9, 12};
bool iSNumbersDivided = numbers.All(number => number % 3 == 0);
Console.WriteLine($"Numbers are divisible by three = {iSNumbersDivided}");

Working with complex types

//Check whether age of all animals in the zoo is greater than 1 year
bool response = animalData.All(x => x.AnimalAge > 1);
Console.WriteLine($"Is All Animals are greater than 1 years old : {response}");

//get all animas who are feed by milk
var zooSubSet = animalData.Where(x => x.Food.All(y => y.FoodType == "Milk"));
foreach(var item in zooSubSet)
{
    Console.WriteLine($"Animal Name: {item.AnimalName}");
}

Resources

https://stackoverflow.com/questions/959752/where-in-clause-in-linq

https://coderedirect.com/questions/644629/linq-nested-list-contains