I want the page to update the mysql database whenever the admin exits the page.
This is a timeline of events:
users submit assignments and The administrator would select a script to mark, when the admin opens the script (in a mark.php page), the page would update the database that someone is marking that particular script and when the admin exits the mark.php page, the page should automatically update the database to show nobody's marking the page.
i created a column in the database to show if someone is marking the script or not, if so it would enter the administrator's user id into the column, and when the admin exits the page it should remove it.
The function to update the database before exiting the page isn't working.
This is what i have
<script>
function exitmarking()
{
return "dsds";
<?php
$connect->executeQuery("UPDATE assignment_submit SET markedby='' WHERE assignment_submit_='$asid'");
?>
}
</script>
and the html
<body onbeforeunload="return exitmarking()"></body>
Since PHP is server-side code, the database query would always be executed before the user ever sees the page rendered - no matter how you structure the location of the PHP code in the page (within your Javascript event).
What you can do is a separate PHP page to do the UPDATE query, and then on exit, use Javascript to do an AJAX call (either native or Jquery or whatever framework you prefer) in your marking javascript function.
Related
When users log into my PHP website, they are automatically logged out after a period of inactivity.
I have a few input fields on the main page for searching for stuff. Input type="text" with JQuery autocomplete option on them. The JQuery autocomplete takes user input and sends it to a PHP file that searches the database and returns data in JSON format.
The original page displays the data returned in a clickable list.
Now, if users have been logged out due to inactivity, this isn't immediately obvious, unless of course they choose to reload the page. Most don't, however. So if they just start entering search words, they just get nothting, because they're not logged in.
I already have a routine to redirect users to the login page if they're not logged in. But this doesn't work in this case, because it's the JSON-generating page that is being redirected, that that doesn't really have any influence on the main page.
Also, I can't see how I can interact directly with what's being returned - it seems like JQuery does all of the data handling internally, so I can't really grab onto data returned and tell the main page to redirect in that case.
How do I achieve the desired result?
On server side ajax first check login condition and based on that give respons e like {login:false} something like that, in your jquery function check that response and if login=false then redirect using window.location.
I'm building a contact form for my website and I would like users to enter their information, click submit, have the information process with php and to just have a message display on the bottom of the form. Originally, I was redirecting to another page and the form was working properly, but now I just want to append a small message and can't get it to work.
This is what I have currently in my contactengine.php file for it to process all the variables and send the email.
if ($success){
THIS IS WHAT I DID BEFORE THAT WORKED BUT HAS TO REDIRECT
// print "<meta http-equiv=\"refresh\" content=\"0;URL=index_thanks.html\">"; //
//BELOW IS WHAT I WANT TO OCCUR
<script type="text/javascript">
$("#contact-area").append("Thanks for your message!")
</script>
}
You don't need JavaScript for this. JavaScript is great, but it should only be used where necessary, since it can add some brittleness to the user experience.
Here's a possible design approach:
Set up a POST form
Process the form, set a session variable to thank the user, and redirect to the form again. This switches the browser from POST to GET mode†, and is usually as simple as this:
header('Location: http://yourdomain.com/form.php');
exit();
Render the form as usual. If a session variable is set to thank the user, render the thank you message, and unset the session variable‡
I wouldn't use a <meta /> refresh here - it needs to load more data to work, and is more fiddly to implement.
† The POST-redirect approach is a common design pattern in web development. There are plenty of resources about this on the web, if you are unfamiliar with it. It fixes problems associated with rendering web content inside a POST method, particularly in relation to page refreshing and using the back/forward buttons.
‡ These temporary session variables are sometimes known as flash variables. They exist from one HTTP operation to the next, and are erased at the end of the second operation.
You cannot put JavaScript inside of your PHP code. However, I will give you an explanation of what you need to do.
On the client side, bind an event for the click, then
$('form button').click(function() {
$.post('file.php', {'object': 'property'}, function(success) {
if(success) {
$("#contact-area").append("Thanks for your message!")
}
});
});
On the server side, you will process this:
//file.php
$sentByAJAX = $_POST['object'];
return true;
I've coded some custom navigation buttons into the project I'm working on, via javascript - they essentially copy the browser button functionality (brief wasn't initially clear on why separate buttons were required, but they asked for them):
function goBack() { window.history.back(); }
function goForward() { window.history.forward(); }
However, as the functionality is the same as the browser back button, the website asks if I want to resubmit POST data if I go back to a page with said POST data, which is undesirable. Ideally, to fit with the current site setup (all POSTs submit to the originating page, which checks for POST data and performs the relevant submissions to the database), I want to clear the POST data so there is no request to resubmit.
I'm not familiar with the Post/Redirect/Get (PRG) that people might recommend, and it doesn't seem to cover the concept of continually pressing "back"; if you submit a form, you post to a page which handles the post action, then redirects to a GET page - but the redirect is still in the history, meaning if you go back, surely you would hit the redirect page and just be sent "forward"? Plus, PRG seems mostly centred on page refreshing, which is not what I'm looking for at the moment.
The concept of PRG also seems to be due to the browser back button not allowing for additional code to control POST data, so coders have to make the best of what they can access.
With my relative freedom of having a custom back button which could allow for manipulation of POST/session/cookie data, I'd consider there should be some method of calling a global session variable or cookie on back button press, which then gets picked up on the previous page load to unset the POST data and the global session variable/cookie, but my attempts to implement something like this have not succeeded - they've been simple single-line setcookie('back', true) or set($_SESSION['back']=true) PHP snippets within goBack(), with PHP earlier in the page:
<?php if (isset([either set cookie or set session variable]) {
unset([either set cookie or set session variable]); // also tried changing 'true' to 'false' here
unset($_POST);
}?>
Is this kind of behaviour possible and I'm just looking at this from the wrong angle, or is the only way to do a successful back action while suppressing POST to re-engineer the site to use PRG, which will be comparatively significant legwork? Is there some other point in a page load/POST submit that would allow for clearing the POST data, to allow for the back button functionality I'm looking for?
EDIT
I, as an example, navigate to site.com/stuff/edit/[an ID], to edit an item of stuff. The first time I visit, there is no POST data, so the PHP check of isset($_POST) returns false and the page is simply rendered with a form which is populated by a GET.
I amend in the form and press submit. The submit sends the POST data to the target page; this is STILL site.com/stuff/edit/[an ID]! However, because there is now POST data, the PHP picks this up, validates it on the page (you'll see why later) and performs backend model and controller functions to update the item to the database serving the site.
Depending on whether the update was successful, the page then renders the form again, with the information which is retrieved from a GET, which pulls the information from the server (amended or otherwise) and either a success or fail message.
If I want to add a new item, I navigate to site.com/stuff/new; this navigates to the same page as site.com/stuff/edit, but PHP code determines the masking URL and renders different aspects of the code to look like a different page with a different POST action - it also notes there is no ID passed in.
I add an item, and the POST redirects back to the same page; this time, though, there is no Id from the server, meaning the code behind picks up the fact it is a new entry, and performs an insert. It then either displays a success message with a link to view/edit the new item, or a failure message with a prepopulated form to reduce retyping the new item into the form.
I hope this has helped show how this page works; its not necessarily how I would have written the site, but I've inherited the work from an ongoing situation and work with others who code in this way, so I need to be consistent or make unobtrusive changes rather than radical redesigns of in-use code.
I think this should do the job:
function goBack() {
var referrer = document.referrer;
if(referrer != '') {
window.location = referrer;
} else {
window.history.back();
}
}
I am trying to use the following javascript code to alert the user when a form has been updated.
Basically what happens is a user clicks on a list of prospective clients, they click edit, this then loads all the clients details into an editor form. Once they have finished editing the user they click the update button and the contents are posted to a php processing script, which also has various other php functions in it that perform other commands before the user is then sent back to the prospect editor where the user details are re loaded into the form again with all the edits applied, this is all done in a second or two.
Once the update has been successful it adds a token into the GET array called update=1 which is passed in the url back to the editor.
What I am trying to do is alert the user when the clients record has been successfully updated by way of an alert box in javascript.
I am using the following code but am no sure how to get the javascript to look for the update=1 in the url and only display update successful when the client has been updated, and not on the initial load when the client is getting loaded from the list of clients.
JAVASCRIPT
<script language="JavaScript">
function prospectupdated ()
{alert("Prospect Updated !")
}
</script>
HTML
<body onLoad="prospectupdated()">
As it stands at the moment it loads every time the page loads, whether the update=1 token in the url is there or not, does anyone know of any tutorials on how to do this, or knows how it do it themselves and doesn't mind sharing ? :-)
Thanks
You need to test the update:
<body <?php isset($_GET['update']) && $_GET['update'] == 1 ? print "onload='prospectupdated()'" : '' ?> >
Look here: How to retrieve GET parameters from javascript?
It will show you how to obtain the value for the update=1.
You would then have an if() statement to check if update=1. If it does, then execute the alert().
I need to do the following:
I have a textbox, which appears in every page of the site, that allows to subscribe to a newsletter. This I've done already and the user is redirected to previous view after subscription.
I'd like to add a javascript alert to the page the user is returned to, something like "Thanks for subscribing". How can this be done?
Thanks in advance.
EDIT: Propably it's not clear from the post tags. I'm using ASP.NET MVC 2 Preview 1
If you are doing a HTTP redirect, then the page you will render needs to be passed some information so that it knows to include the javascript to open the alert box (adding an optional element to the page might be a nicer way to do this).
That information needs to be stored either in a browser cookie, or in a session store (which is keyed from a browser cookie). You can remove this once you've rendered your message, so that it is only shown the first time you visit that page after the redirect.