PHP Form Submission: Recognize Image Input Buttons
As you probably know, you can recognize a form submission from a "submit" input type by placing the following code in the "processing" PHP script:
if(isset($_POST['submit'])) { /* do stuff */ }
Did you know, however, that when using an "image" input type to submit the form, the above wont work? You need to add a "_x" to the field name in PHP:
if(isset($_POST['submit_x'])) { /* do stuff */ }
Odd, huh? This works the same when using a form "GET" method.
![How I Stopped WordPress Comment Spam]()
I love almost every part of being a tech blogger: learning, preaching, bantering, researching. The one part about blogging that I absolutely loathe: dealing with SPAM comments. For the past two years, my blog has registered 8,000+ SPAM comments per day. PER DAY. Bloating my database...
![6 Things You Didn’t Know About Firefox OS]()
Firefox OS is all over the tech news and for good reason: Mozilla's finally given web developers the platform that they need to create apps the way they've been creating them for years -- with CSS, HTML, and JavaScript. Firefox OS has been rapidly improving...
![Introducing MooTools NextPrev]()
One thing I love doing is duplicating OS functionalities. One of the things your OS allows you to do easily is move from one item to another. Most of the time you're simply trying to get to the next or the previous item.
![Add Controls to the PHP Calendar]()
I showed you how to create a PHP calendar last week. The post was very popular so I wanted to follow it up with another post about how you can add controls to the calendar. After all, you don't want your...
The _x and _y represent the coordinate location you clicked the image at.
Think this is only an issue with IE.
Yeah. The _x- and _y-coordinates are great for improving the security of a form! I’ve used this to determine if the form has been filled by a human. A spam-bot won’t submit any coordinates but a human has to click on the button and so there will always be coordinates (you’ll have to deactive submitting with the ENTER-button).
@Matthias: Good point on the security enhancement — I’ve never though of that!
@ Matthias
Thanks for posting your comment. I think telling the user that the ENTER button has been deactivated for bot protection is easier than having the user type in a captcha.
I’ll definitely be looking into that method and most likely incorporating it into my projects.
@Braxo – Wait – “Enter button” is deactivated? How would this affect someone who cannot use a mouse/relies on accessibility tools to fill out forms and the like?
Some sites cannot get away with it (coughtargetcough).
You can save yourself the trouble and just give the input a name attribute and check for that. Saves from changing code in two places (the input and the PHP submit validation).
<input type="image" src="image.png" name="submitted" value="Submit" />
I should clarify that…
It saves from changing code in 2 places should you want to change to/from an image submit or a standard submit.