Validate user input for extra long words in textarea

Question

I have a problem here with validating user's input in textarea. A user is suppose to enter his description in one of the textarea feild in form. But some people just put the random text like 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa' or something to bypass the minimum length requirement.

Now i want to prevent user from typing such long text without any spaces since it disrupts the UI of my page. Also a long text entered by user without any spaces can be a valid url too. So how do i manage this & throw a error to user to correct the text only if it is too long and it isnt a valid url ??

PS: I dont want to split string myself.. I just want to detect it and throw error to user on client side validation. Just to put end to some doubts, i will do server side validation in which i will forcibly enter a space and save it in DB. But i am expecting to solve this problem on client side

Answer 1

function validate()
{
  var expression = /[-a-zA-Z0-9@:%_\+.~#?&//=]{2,256}\.[a-z]{2,4}\b(\/[-a-zA-Z0-9@:%_\+.~#?&//=]*)?/gi;
  var wordLengthExpr = /\b[^\s]{50,}\b/;
  var regex = new RegExp(expression);
  var wordLengthRegex = new RegExp(wordLengthExpr);
  var t = $("#myTextarea").val();
  if (t.match(regex) ||  !t.match(wordLengthRegex))
  {
    //valid
  }
  else
  {
    //throw error
  }
}

Answer 2

var STRING_MAX_LENGTH = 10;

var description = 'aaa aaaaaaaaaa bbbbbbbbbb http://www.google.com/search?q=client-side-filtering';
var array = description.split( ' ' );

$.each( array, function() {
  if ( this.length >= STRING_MAX_LENGTH ) {
    if( /^([a-z]([a-z]|\d|\+|-|\.)*):(\/\/(((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:)*@)?((\[(|(v[\da-f]{1,}\.(([a-z]|\d|-|\.|_|~)|[!\$&'\(\)\*\+,;=]|:)+))\])|((\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5])\.(\d|[1-9]\d|1\d\d|2[0-4]\d|25[0-5]))|(([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=])*)(:\d*)?)(\/(([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)*)*|(\/((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)+(\/(([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)*)*)?)|((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)+(\/(([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)*)*)|((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)){0})(\?((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)|[\uE000-\uF8FF]|\/|\?)*)?(\#((([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(%[\da-f]{2})|[!\$&'\(\)\*\+,;=]|:|@)|\/|\?)*)?$/i . test( this ) ) {
      alert( this + ' is an URL' );
    } else {
      alert( this + ' is not an URL' );
    }
  }
});

http://jsfiddle.net/vVYAp/

Answer 3

This is a two step process:

1. Determine if any words are too long.
2. If so, determine if they are valid URLs.

var validateWordLength = function (str) {
    var maxLength = 50,  // or whatever max length you want
        reURL = /^(ftp|http|https):\/\/[^\s]+$/, // use whatever regular expression for URL matching you feel best
        words = str.split(/\s+/),
        i;

    for (i = 0; i < words.length; i += 1) {
        if (words[i].length > maxLength) {
            // test for url
            // but bear in mind the answer at http://stackoverflow.com/questions/1410311/regular-expression-for-url-validation-in-javascript
            // testing for url may not be fruitful
            if (!reURL.test(words[i])) {
                return false;
            }
        }
    }

    return true;
};

Answer 4

try this

    var value = Your text;

    var result = value.replace(" ","");

if(value.length == result .length)
  //not valid
else
 //valid

Answer 5

You can get length of each word, and then can decide whether to allow the user or not -

var arr = text.split(' ');

$.each(arr,function(){
   console.log(this.length);
   // check valid word length
}); 

http://jsfiddle.net/mohammadAdil/cNZtn/

Answer 6

If you use the jQuery validate plugin you can add a method to it:

jQuery.validator.addMethod("samechars", function(value, element) { 
    return this.optional(element) ||  !/([a-z\d])\1\1/i.test(value); 
}, "Invalid input");

Answer 7

If you want to use jQuery you can use the following:

$("form").submit(function(e){
var $textarea = $('#msg'),
    maxWordLength = 20;

            var value = $textarea.val().split(' '),
                longWord = false;

            for(var n = 0; n < value.length; n++) {
                if(value[n].length >= maxWordLength)
                    longWord = true;
            }

if(longWord) {
    alert('Too long word');
    return false;
}
});

Here is a fiddle: http://jsfiddle.net/pJgyu/31286/