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I'm looking for a javascript that can limit the number of lines (by line I mean some text ended by user pressing enter on the keyboard) the user is able to enter in textarea. I've found some solutions but they simply don't work or behave really weird. The best solution would be a jquery plugin that can do the work - something like CharLimit, but it should be able to limit text line count not character count.
904
We can define the visible width and height of a TextArea either using the cols and rows attributes or the style properties: width and height , but we cannot set a limit to the number of characters or the number of lines for the text entered into the TextArea by using HTML or CSS.
The HTML <Textarea>maxlength attribute is used to specify the maximum number of characters enters into the Textarea element. Attribute Value: number: It contains single value number which allows the maximum number of character in Textarea element. Its default value is 524288.
val(); var lines = text. split(/(\r\n|\n|\r)/gm); for (var i = 0; i < lines. length; i++) { if (lines[i]. length > maxLength) { lines[i] = lines[i].
The HTML textarea wrap Attribute is used to specify that in which manner the text is to be wrapped in a text area when a form is submitted. Attribute Values: soft: It specifies that the Text present in the Textarea would not be wrapped after submitting the form. This is the default value.
This might help (probably be best using jQuery, onDomReady and unobtrusively adding the keydown event to the textarea) but tested in IE7 and FF3:
<html>
<head><title>Test</title></head>
<body>
<script type="text/javascript">
var keynum, lines = 1;
function limitLines(obj, e) {
// IE
if(window.event) {
keynum = e.keyCode;
// Netscape/Firefox/Opera
} else if(e.which) {
keynum = e.which;
}
if(keynum == 13) {
if(lines == obj.rows) {
return false;
}else{
lines++;
}
}
}
</script>
<textarea rows="4" onkeydown="return limitLines(this, event)"></textarea>
</body>
</html>
*Edit - explanation: It catches the keypress if the ENTER key is pressed and just doesn't add a new line if the lines in the textarea are the same number as the rows of the textarea. Else it increments the number of lines.
Edit #2: Considering people are still coming to this answer I thought I'd update it to handle paste, delete and cut, as best as I can.
<html>
<head>
<title>Test</title>
<style>
.limit-me {
height: 500px;
width: 500px;
}
</style>
</head>
<body>
<textarea rows="4" class="limit-me"></textarea>
<script>
var lines = 1;
function getKeyNum(e) {
var keynum;
// IE
if (window.event) {
keynum = e.keyCode;
// Netscape/Firefox/Opera
} else if (e.which) {
keynum = e.which;
}
return keynum;
}
var limitLines = function (e) {
var keynum = getKeyNum(e);
if (keynum === 13) {
if (lines >= this.rows) {
e.stopPropagation();
e.preventDefault();
} else {
lines++;
}
}
};
var setNumberOfLines = function (e) {
lines = getNumberOfLines(this.value);
};
var limitPaste = function (e) {
var clipboardData, pastedData;
// Stop data actually being pasted into div
e.stopPropagation();
e.preventDefault();
// Get pasted data via clipboard API
clipboardData = e.clipboardData || window.clipboardData;
pastedData = clipboardData.getData('Text');
var pastedLines = getNumberOfLines(pastedData);
// Do whatever with pasteddata
if (pastedLines <= this.rows) {
lines = pastedLines;
this.value = pastedData;
}
else if (pastedLines > this.rows) {
// alert("Too many lines pasted ");
this.value = pastedData
.split(/\r\n|\r|\n/)
.slice(0, this.rows)
.join("\n ");
}
};
function getNumberOfLines(str) {
if (str) {
return str.split(/\r\n|\r|\n/).length;
}
return 1;
}
var limitedElements = document.getElementsByClassName('limit-me');
Array.from(limitedElements).forEach(function (element) {
element.addEventListener('keydown', limitLines);
element.addEventListener('keyup', setNumberOfLines);
element.addEventListener('cut', setNumberOfLines);
element.addEventListener('paste', limitPaste);
});
</script>
</body>
</html>
How to do it with jQuery:
Bind to keyDown event of textarea.
function limitTextareaLine(e) {
if(e.keyCode == 13 && $(this).val().split("\n").length >= $(this).attr('rows')) {
return false;
}
}
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