jQuery textarea length verification_jquery

Extend the textarea attribute and combine it with jquery.validate.js to verify the length of the textarea while submitting the form.
1.jQuery plug-in to verify textarea length

Copy code The code is as follows:

//Verify textarea length
jQuery.fn.checkLength = function(parameters) {
defaults = {
min: 0
, max: 5
}
jQuery. extend(defaults, parameters);
//The value of the current textarea
var taValue = $(this).val();
var len = taValue.length;
if (len >= defaults.max) {
$(this).parent().append(showLengthError("max")).show();
window.setTimeout(function() {
$(".lenError ").hide();
}, 5000);
return false;
} else if (len <= defaults.min) {
$(this).parent().append (showLengthError("min"));
window.setTimeout(function() {
$(".lenError").hide();
}, 5000);
return false;
} else {
return true;
}
//todo: When the keyboard input is within the correct range, eliminate the prompt
}

comment :
1) Parameter passing:
defaults = {
min: 0
, max: 5
}
are used to receive the minimum and maximum length of the textarea respectively .
2) Return value
true: Verification length passed
false: Verification length failed
2. Instructions for use:
Add js reference to the page:

Example:
In page

Check Textarea Length
When the button event is triggered , we can judge the length of textarea.

Copy code The code is as follows:

$("#chklen").click(function( ){
var bool = $("#txtContent").checkLength({
min : -1
,max: 10
});
if(bool){
alert(bool);
}
});

If the textarea is in the form, it will be verified when the form is submitted, and then submitted when the conditions are met. .
The following example:

Copy code The code is as follows:

// Determine whether the testarea length is Exceeding the limit
var ckContent = $("#txtContentIntro").checkLength({
min : -1 //Does not judge whether it is empty
,max: 512 //Maximum length 512
}) ;
// Form validation
var b = $("#fcourseware").valid();
// Perform upload operation and save courseware information after successful upload
if (b && ckContent ) {
// todo: submit form
}

Both the min and max parameters do not need to pass a value. The default minimum length is 0 and the maximum length is 10. If textarea is not required item, then the min value is assigned -1.
Finally, the operation is performed by returning a bool value.