ajax alert is not working using codeigniter - ajax

Question

I am newer to ajax. I want to add two fields using ajax and codeigniter.. When i click the submit button the two fields are added but the alert message is not showing also the page is not refreshing. Can any one solve my issue.. Thanks in advance..
This is my Form
<form action="" id="suggestionsform" method="post">
<div class="form-group">
<label for="suggname">Name</label>
<input type="text" class="form-control" name="suggname" id="suggname" placeholder="Enter Your Name" required="required">
</div>
<div class="form-group">
<label for="suggmessage">Suggestion</label>
<textarea class="form-control" rows="4" name="suggmessage" id="suggmessage"
placeholder="Enter Your Suggestions"></textarea>
</div>
<button type="submit" class="btn btn-default" id="suggestions">Submit</button>
</form>
This is my ajax codeing
<script>
// Ajax post
$(document).ready(function() {
$("#suggestions").click(function(event) {
event.preventDefault();
var name = $("#suggname").val();
var suggestion = $("#suggmessage").val();
$.ajax({
type: "POST",
url: "<?php echo site_url('Helen/addSuggestion')?>",
dataType: 'json',
data: {name: name, suggestion: suggestion},
success: function(data) {
if (data=='true')
{
alert("Thank you for your Suggestion");
}
}
});
});
});
</script>
Controller Coding
public function addSuggestion()
{
$data=array(
'name' => $this->input->post('name'),
'messages' => $this->input->post('suggestion'),
'date' => now()
);
$data=$this->Helen_model->setSuggestion($data);
echo json_encode($data);
}
Model Coding
public function setSuggestion($data){
$this->db->insert('messages', $data);
return $this->db->insert_id();
}

Answer 1

You can achieve like this..
Model
Return true status if insert successful.
public function setSuggestion($data){
$res = $this->db->insert('messages', $data);
if($res){
$result = array('status'=>true,'message'=>'successful');
}
else
{
$result = array('status'=>false,'message'=>'failed');
}
return $result;
}
JS
Check status in success function
<script>
// Ajax post
$(document).ready(function() {
$("#suggestions").click(function(event) {
event.preventDefault();
var name = $("#suggname").val();
var suggestion = $("#suggmessage").val();
$.ajax({
type: "POST",
url: "<?php echo site_url('Helen/addSuggestion')?>",
dataType: 'json',
data: {name: name, suggestion: suggestion},
success: function(response) {
data = eval(response);//or data = JSON.parse(response)
if (data.status ===true)
{
alert("Thank you for your Suggestion");
}
}
});
});
});
</script>

Answer 2

Try to use echo '{"status": "success"}; on your controller response.
That i see on your script you are shown database response.