Disable buttons unless button is pressed

1
votes

I would like to disable some buttons until a button is pressed.

The first button (button1) generates a file. The rest of the buttons have something to do with that file (view, download, etc.)

I tried disabling the buttons until the first button was pressed, but as I'm using a post request the page is refreshed when I hit button1 and everything is reset.

I was thinking along the lines of grep-ing for the file and assigning that to a variable in PHP then disable/enable the buttons based off whether or not that file is there, but I'm unsure how to do the PHP/JS crossover. Any guidance would be appreciated.

3
javascriptphpbutton
you could use a ajax function to post the data from the 1st button that would mean no page refresh and so the buttons would then be enabled? - akaBase
you really don't need an ajax for this. what i would do is save it in a session, before any session is saved, disable the buttons view, download, etc., after the file is created, then save a session, that will determine the attribute disabled on the buttons - Kevin

3 Answers

1
votes

You should use asynchronous page loading. Just send a request string to the server and it echoes you an answer back., without reloading page.

 var jstring = JSON.stringify(request); //wrap up your specification in an JSON  
$.ajax({
            type: "POST",
            contentType: "application/json; charset=utf-8",
            url: "http://" + window.location.hostname +  "/request",
            data: jstring,
            success: function(response) {
                //... enable buttons
            },
            error: function(response) {
               //... file could not be loaded 
            }
        });

In PHP

if ($_GET["type"] === 'request') {
    $jsonraw = $decode ? utf8_encode(file_get_contents("php://input")) : file_get_contents("php://input");
        $jsonstring = json_encode($jsonraw, true);
        $array = json_decode($jsonraw, true);
//... do something with $array
}
0
votes

What you need is called AJAX.

Make an AJAX call on click of the first button to a php file that checks for the above mentioned file. Set the PHP to return true if file is found and false if not.

Finally, in the callback of the ajax make the javascript changes if returned code is success.

I will not write the code for you, but I'll give you a link. It should be more than enough.

http://api.jquery.com/jquery.ajax/

Note that you need jQuery to execute the example.

0
votes

You can also do this without an ajax. You can also do this using sessions.

Save it in a session, before any session is saved, disable the buttons view, download, etc., after the file is created, then save a session, that will determine the disabled attribute.

Rough Example:

session_start();

if(isset($_POST['create_file'])) {
    $_SESSION['file_exists'] = true;
    // generate file blah blah
    echo 'File created: stackoverflow.jpg <br/>';
}

// now you decide when to destroy the session for this
// unset($_SESSION['file_exists']);


?>
<form method="POST">
    <input type="submit" name="create_file" value="Create File" /><br/><hr/>

    <input type="submit" name="view_file" value="View File" <?php echo !isset($_SESSION['file_exists']) ? 'disabled' : ''; ?> /><br/>
    <input type="submit" name="download_file" value="Download File" <?php echo !isset($_SESSION['file_exists']) ? 'disabled' : ''; ?>  /><br/>
</form>