Regular Expression to avoid HTML tags and empty values

Question

I have applied a textbox click validation and wanted to avoid any html tags in text box also the simple < (open tag) and >(close tag). The below code is working for but i want to add additional validations also for empty strings and other tags in html. Can some one please help modify the regex for the requirement.

function htmlValidation() 
 {
   var re = /(<([^>]+)>)/gi;

   if (document.getElementById(’<%=TextBox2.ClientID%>’).value.match(re)){ document.getElementById(’<%=TextBox2.ClientID%>’).value = “”;
          return false;
        }
   return true;
 }

Corrected Code above

Answer 1

In my opinion, I believe you'll have a good hard work if you want to validate such things.

Instead of preventing HTML content in a text box, other solution could be just html entity encode Text property, so <p>a</p> would be converted to >p<a>p< .

Result of that is you're going to render the HTML "as text" instead of getting it interpreted by Web browser.

Check this MSDN article:

• http://msdn.microsoft.com/en-us/library/73z22y6h(v=vs.110).aspx

Answer 2

$("#<%= btnAdd.ClientID %>").click(function () {
            var txt = $("#<%= txtBox1.ClientID %>");
            var svc = $(txt).val();  //Its Let you know the textbox's value 
            var re = /(<([^>]+)>)/gi;
            if(txt.val()!=""){
            if (!txt.val().match(re)) {
               //my Operations 
               //goes here
                });
                return false;
            }
            else {
                alert("Invalid Content");
            }
            }
            else {
            alert("Blank value selected");
            }

I have used Jquery function to check for regular expresion. This question is a linked question with Using Jquery to add items in Listbox from Textbox

Now i can mark this as my final answer.