CODEWITHSUNDEEP
javascriptjqueryregexwhitespaceremoving-whitespace
Thomas Sebastian
Thomas Sebastian

Reputation: 1612

Disallow only whitespaces or show alert only if the user types letters

The user is supposed to enter some information in the textarea (inside p tag in my case) which is mainly strings. However, I want to stop the user from only entering whitespaces[continuous multiple whitespaces], on which I will alert him asking to type something meaningful. How do I check for this condition? Is "if there are no normal alphabets; then alert blahblah" a working logic? How do I code this?

Code so far

$("#saveText").click(function() {
  var grabbed = $(".froala-element p").text();
  if (grabbed === "") {
    alert("No cheating :) Please type something.");
  } else {
    alert(grabbed);
  }
});

This is all I got so far. A jQuery solution is also welcome.

Upvotes: 2

Views: 210

Answers (3)

Chetan
Chetan

Reputation: 2756

Try to listen for 'blur' and 'paste' event to make sure blank characters aren't entered by user, as show below:-

http://jsfiddle.net/chetanbh/024jvy5h/

$('#type_something').on('paste', function(event){
var element = this;
setTimeout(function () {
    var text = $(element).val();
    if(text.trim().length <= 0) {
        alert('Sorry, paste something else, not empty string');
        $(element).val('');
    }
}, 100);

});

$('#type_something').on('blur', function(event){
var element = this;
var text = $(element).val();
if(text.trim().length <= 0) {
    alert('Sorry, type something else, not blank characters');
    $(element).val('');
}

});

Upvotes: 0

Robby Cornelissen
Robby Cornelissen

Reputation: 97150

You could test against a regular expression that represents only whitespace (/^\s*$/):

$("#saveText").click(function() {
  var grabbed = $(".froala-element p").text();

  if (/^\s*$/.test(grabbed)) {
    alert("No cheating :) Please type something.");
  } else {
    alert(grabbed);
  }
});

This handles regular spaces, tabs, newlines, etc., as well as the case where there's no input.

The regular expression itself decomposes as follows:

^    Beginning of the string
\s   Any whitespace character
*    Zero or more occurrences of previous
$    End of the string

You could alternatively turn the test around and check for the presence of at least one non-whitespace character using /\S/, which is probably slightly more efficient.

Upvotes: 3

webon
webon

Reputation: 88

If the text is in 'p' tag, your code is all right, if it is textarea, it should be:

var grabbed = $(".froala-element textarea").val();

Upvotes: 0

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