If You are trying to validate select2 field using jquey.validation plugin but nothing happens You can check this link: https://github.com/rkeshmir/select2-validation
Here you can find the simplest way to validate select2 components. The idea id trigger validation for all <select> items in DOM on their change event. Also I have added required CSS rules to highlight error and success states of input.
This is a sample code of applying jQuery Validation Plugin (http://jqueryvalidation.org/) on select2 (https://select2.github.io/) components
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title>Select2 - Form Validation</title>
<!-- inject:css -->
<!-- endinject -->
<style rel="stylesheet">
#example {
border: solid 1px grey;
border-radius: 4px;
padding: 4px;
}
.select {
width: 100%;
}
.select2-input {
border-radius: 4px;
}
/* for validation */
.has-success .select2-selection , .has-success .select2-container,
.has-success .select2-choice, .has-success .select2-choices {
border-color: #3c763d;
box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075) inset;
}
.has-success .select2-selection:focus , .has-success .select2-container:focus,
.has-success .select2-choice:focus, .has-success .select2-choices:focus {
border-color: #2b542c;
box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075) inset, 0 0 6px #67b168;
}
.has-error .select2-selection , .has-error .select2-container,
.has-error .select2-choice, .has-error .select2-choices {
border-color: #a94442;
box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075) inset;
}
.has-error .select2-selection:focus , .has-error .select2-container:focus,
.has-error .select2-choice:focus, .has-error .select2-choices:focus{
border-color: #843534;
box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075) inset, 0 0 6px #ce8483;
}
.select2-choices {
border-radius: 4px;
}
/* .has-success .select2-choice {
border-color: #3c763d;
box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075) inset;
}
.has-success .select2-choice:focus {
border-color: #2b542c;
box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075) inset, 0 0 6px #67b168;
}
.has-error .select2-choice {
border-color: #a94442;
box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075) inset;
}
.has-error .select2-choice:focus {
border-color: #843534;
box-shadow: 0 1px 1px rgba(0, 0, 0, 0.075) inset, 0 0 6px #ce8483;
}*/
</style>
</head>
<body>
<sction id="header" >
<div class="row">
Demo under construction
</div>
</sction>
<sction id="main">
<div class="row">
<div class="col-md-10 col-md-offset-1 col-sm-12" id="example">
<form class="form-horizontal" action="" id="theForm">
<div class="form-group">
<label for="inputEmail3" class="col-sm-2 control-label">Email</label>
<div class="col-sm-10">
<input name="email" type="email" class="form-control" id="inputEmail3" placeholder="Email" required>
</div>
</div>
<div class="form-group">
<label for="inputPassword3" class="col-sm-2 control-label">Password</label>
<div class="col-sm-10">
<input name="password" type="password" class="form-control" id="inputPassword3" placeholder="Password" required>
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<div class="checkbox">
<label>
<input name="remember" type="checkbox"> Remember me
</label>
</div>
</div>
</div>
<div class="form-group">
<label for="inputSelect3" class="col-sm-2 control-label">Favourite Color</label>
<div class="col-sm-10">
<select name="color" class="select" id="inputSelect3" placeholder="Select Color" required>
<option>Red</option>
<option>Blue</option>
<option>Green</option>
<option>Yellow</option>
<option>Brown</option>
<option>Orange</option>
</select>
</div>
</div>
<div class="form-group">
<label for="inputSelect4" class="col-sm-2 control-label">Favourite Fruits</label>
<div class="col-sm-10">
<select name="fruits" class="select" id="inputSelect4" placeholder="Select Fruits"
multiple="multiple" required>
<option>Apple</option>
<option>Bananas</option>
<option>Grapes</option>
<option>Pears</option>
<option>Strawberry</option>
<option>Blueberry</option>
<option>Pomegranate</option>
</select>
</div>
</div>
<div class="form-group">
<div class="col-sm-offset-2 col-sm-10">
<button type="submit" class="btn btn-default">Sign in</button>
</div>
</div>
</form>
</div>
</div>
</sction>
<sction id="footer">
<div class="row">
Designed and developed by <a href="htt://rkeshmir.ir">Reza Keshmir</a>
</div>
</sction>
<!-- inject:js -->
<!-- endinject -->
<script type="text/javascript">
$(".select").select2({
});
$('#theForm').validate(
{
errorPlacement: function(error, element) {},
highlight: function(element) {
$(element)
.closest('.form-group')
.removeClass('has-success')
.addClass('has-error');
},
unhighlight: function(element) {
$(element)
.closest('.form-group')
.removeClass('has-error')
.addClass('has-success');
}
}
);
$('select').on('change', function() { // when the value changes
$(this).valid(); // trigger validation on this element
});
</script>
</body>
</html>
Source:
https://github.com/rkeshmir/select2-validation
https://stackoverflow.com/questions/23825135/how-to-make-select2-work-with-jquery-validation-plugin