program php and alert javascript on form html

Question

i have a problem with my simple program in php that include an alert javascript. This is the code:

<?php

function iva(){
$country='IT';
$vatnum=$_POST['n'];

$a="Work";
$b="NotWork";

$url='http://isvat.appspot.com/'.$country.'/'.$vatnum.'/';
 $response = file_get_contents($url);
//global $a, $b;
if( $response == 'true' ){
echo $a;
}
if ($response != 'true'){
echo $b;
}
}
?>
<script>
function ivaz(){

alert("<?php iva() ?>");

}
</script> 

<form method="post">
<input name="n"  type="textarea" >
<input  onclick="ivaz();" value="Validate" type="submit"> </input> </form>

My program take a value from input text box and pass the value to php script that return true or false in a javascript alert. The program work, but return previous value passed in input box. Can someone help me to solve it?

Thanks guys.

You should first learn the differences between server side scripting and client side scripting. — Jerodev
– Jerodev, Commented Oct 16, 2014 at 11:01

Kevin · Accepted Answer · 2014-10-16 11:08:42Z

3

No, it doesn't work that way. If you want to call a PHP function from Javascript without the page refreshing, you need an XMLHttpRequest.

Example:

<?php
// your php process when called by XMLHttpRequest
if($_SERVER['REQUEST_METHOD'] == 'POST') {
    $vatnum = $_POST['n'];
    $country='IT';
    $a = "Work";
    $b = "NotWork";

    $url = 'http://isvat.appspot.com/'.$country.'/'.$vatnum.'/';
    $response = file_get_contents($url);
    //global $a, $b;
    if( $response == 'true' ){
        echo $a;
    } else {
        echo $b; 
    }
    exit;
}

?>

<form method="post" id="form1">
    <input name="n" type="text" id="n" />
    <input value="Validate" type="submit">
</form>

<script type="text/javascript">
// when the form is submitted
document.getElementById('form1').addEventListener('submit', function(e){
    e.preventDefault(); 
    var n = document.getElementById('n').value; // get the textbox value
    var xmlhttp = new XMLHttpRequest();
    var params = 'n=' + n;
    var php_url = document.URL;
    xmlhttp.open('POST', php_url, true);

    xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

    xmlhttp.onreadystatechange = function() {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
            var response = xmlhttp.responseText;
            alert(response); // alert the server response
        }
    }

    xmlhttp.send(params);
});
</script>

answered Oct 16, 2014 at 11:08

Kevin

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10 Comments

Marcello Mönkemeyer Over a year ago

Note: Using jQuery is highly recommended for maximum browser compatibility.

Kevin Over a year ago

@Icefyre if jquery is tagged, i could have answer it with it. but since its not there. i did not

Kevin Over a year ago

@Icefyre even fuzzy people here downvote answers with jquery code with a non jquery tagged question even if its correct.

Marcello Mönkemeyer Over a year ago

Didn't know that, but will keep it in mind for the future. Thank you.

BlekZ Over a year ago

the code work!! thanks. If i want load this code on another javascript? it's possible?

|

Vicky Gonsalves · Accepted Answer · 2014-10-16 11:01:49Z

0

Remove onclick="ivaz();" from input tag

answered Oct 16, 2014 at 11:01

Vicky Gonsalves

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Comments

cypher75 · Accepted Answer · 2014-10-16 11:04:20Z

0

You cannot run the php script without reloading the page as php is generated serverside and javascript runs clientside.

answered Oct 16, 2014 at 11:04

cypher75

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