jQuery Post and Get Form data - php

Question

When a form is submitted, I can get its field values with $_POST. However, I am trying to use a basic jQuery (without any plugin) to check if any field was blank, I want to post the form content only if theres no any blank field.
I am trying following code, and I got the success with jQuery, but the only problem is that I am unable to post the form after checking with jQuery. It does not get to the $_POST after the jQuery.
Also, how can I get the server response back in the jQuery (to check if there was any server error or not).
Here's what I'm trying:
HTML:
<form action="" id="basicform" method="post">
<p><label>Name</label><input type="text" name="name" /></p>
<p><label>Email</label><input type="text" name="email" /></p>
<input type="submit" name="submit" value="Submit"/>
</form>
jQuery:
jQuery('form#basicform').submit(function() {
//code
var hasError = false;
if(!hasError) {
var formInput = jQuery(this).serialize();
jQuery.post(jQuery(this).attr('action'),formInput, function(data){
//this does not post data
jQuery('form#basicform').slideUp("fast", function() {
//how to check if there was no server error.
});
});
}
return false;
});
PHP:
if(isset($_POST['submit'])){
$name = trim($_POST['name'];
$email = trim($_POST['email'];
//no any error
return true;
}

Answer 1

To be very specific to the question:
How can I get the server response back in the jQuery (to check if
there was any server error or not). Here's what I'm trying:
Sound like you're talking about Server-Side validation via jQuery-Ajax.
Well, then you need:
Send JavaScript values of the variables to PHP
Check if there any error occurred
Send result back to JavaScript
So you're saying,
However, I am trying to use a basic jQuery (without any plugin) to
check if any field was blank, I want to post the form content only if
there's no any blank field.
JavaScript/jQuery code:
Take a look at this example:
<script>
$(function()) {
$("#submit").click(function() {
$.post('your_php_script.php', {
//JS Var //These are is going to be pushed into $_POST
"name" : $("#your_name_field").val(),
"email" : $("#your_email_f").val()
}, function(respond) {
try {
//If this falls, then respond isn't JSON
var result = JSON.parse(respond);
if ( result.success ) { alert('No errors. OK') }
} catch(e) {
//So we got simple plain text (or even HTML) from server
//This will be your error "message"
$("#some_div").html(respond);
}
});
});
}
</script>
Well, not it's time to look at php one:
<?php
/**
* Since you're talking about error handling
* we would keep error messages in some array
*/
$errors = array();
function add_error($msg){
//#another readers
//s, please don't tell me that "global" keyword makes code hard to maintain
global $errors;
array_push($errors, $msg);
}
/**
* Show errors if we have any
*
*/
function show_errs(){
global $errors;
if ( !empty($errors) ){
foreach($errors as $error){
print "<p><li>{$error}</li></p>";
}
//indicate that we do have some errors:
return false;
}
//indicate somehow that we don't have errors
return true;
}
function validate_name($name){
if ( empty($name) ){
add_error('Name is empty');
}
//And so on... you can also check the length, regex and so on
return true;
}
//Now we are going to send back to JavaScript via JSON
if ( show_errs() ){
//means no error occured
$respond = array();
$respond['success'] = true;
//Now it's going to evaluate as valid JSON object in javaScript
die( json_encode($respond) );
} //otherwise some errors will be displayed (as html)

Answer 2

You could return something like {"error": "1"} or {"error": "0"} from the server instead (meaning, put something more readable into a JSON response). This makes the check easier since you have something in data.
PHP:
if(isset($_POST['submit'])){
$name = trim($_POST['name'];
$email = trim($_POST['email'];
//no any error
return json_encode(array("error" => 0));
} else {
return json_encode(array("error" => 1));
}
JavaScript:
jQuery('input#frmSubmit').submit(function(e) {
//code
var hasError = false;
if(!hasError) {
var formInput = jQuery(this).serialize();
jQuery.post(jQuery(this).attr('action'),formInput, function(data){
var myData = data;
if(myDate.error == 1) {//or "1"
//do something here
} else {
//do something else here when error = 0
}
});
}
$("form#basicform").submit();
return false;
});

Answer 3

There are two ways of doing that
Way 1:
As per your implementation, you are using input[type="submit"] Its default behavior is to submit the form. So if you want to do your validation prior to form submission, you must preventDefault() its behaviour
jQuery('form#basicform').submit(function(e) {
//code
e.preventDefault();
var hasError = false;
if(!hasError) {
var formInput = jQuery(this).serialize();
jQuery.post(jQuery(this).attr('action'),formInput, function(data){
//this does not post data
jQuery('form#basicform').slideUp("fast", function() {
//how to check if there was no server error.
});
});
}
$(this).submit();
return false;
});
Way 2:
Or simply replace your submit button with simple button, and submit your form manually.
With $("yourFormSelector").submit();
Change your submit button to simple button
i.e
Change
<input type="submit" name="submit" value="Submit"/>
To
<input id="frmSubmit" type="button" name="submit" value="Submit"/>
And your jQuery code will be
jQuery('input#frmSubmit').on('click',function(e) {
//code
var hasError = false;
if(!hasError) {
var formInput = jQuery(this).serialize();
jQuery.post(jQuery(this).attr('action'),formInput, function(data){
//this does not post data
jQuery('form#basicform').slideUp("fast", function() {
//how to check if there was no server error.
});
});
}
$("form#basicform").submit();
return false;
});
To get the response from the server, you have to echo your response.
Suppose, if all the variables are set, then echo 1; else echo 0.
if(isset($_POST['submit'])){
$name = trim($_POST['name'];
$email = trim($_POST['email'];
echo 1;
} else {
echo 0;
}
And in your success callback function of $.post() handle it like
jQuery.post(jQuery(this).attr('action'),formInput, function(data){
//this does not post data
jQuery('form#basicform').slideUp("fast",{err:data}, function(e) {
if(e.data.err==1){
alert("no error");
} else {
alert("error are there");
});
});