php exec command does not work within ajax call

Question

I am using jQuery 2.0.2 with ajax to call a php page which executes a command to start a java client:

        $j(document).ready(function(){
            $j(".do_remote_sync").on("click",function(event) {                       
                var d = "";
                $j.ajax({
                    data: \'test=test2\',
                    type: \'POST\',
                    url: \'sync_remote.php\',
                    success: function(data) {
                        d = data;
                    }
                });                        
                //alert("after ajax");
            });
        });

The sync_remote.php page only contains following line:

exec("java -jar RemoteSync.jar config.properties", $output, $return_var);

The problem is now that the sync_remote.php page is only called if I write an "alert" command after the ajax call (alert("after ajax");).

If I comment out this line the ajax call is most probably not called!

The sync_remote.php page works without problems if a call it directly.

Question

Why the ajax call is not executed without the "alert" command?

SLaks · Accepted Answer · 2013-06-04 13:50:37Z

2

This would happen if .do_remote_sync is a hyperlink.

Clicking the hyperlink navigates to its href, cancelling any active AJAX requests.
Adding an alert() gives the AJAX request enough time to make it to the server before that happens.

You need to return false to prevent the navigation.

answered Jun 4, 2013 at 13:50

SLaks

891k182 gold badges1.9k silver badges2k bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

sk2212 Over a year ago

It is a submit form element: <input class="do_remote_sync" type="submit" />. Does it behave the same like a hyperlink?

SLaks Over a year ago

@sk2212: Yes; it submits the form.

sk2212 Over a year ago

Thats the problem! Thanks!

Collectives™ on Stack Overflow

php exec command does not work within ajax call

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related