Completing a Noisy Image Application
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If you're searching for an approachable guide on how to build noisy images to help prevent automated submission of online forms, then look no further. Welcome to the final article of the series "Building Noisy Images." Over the course of this instructive series, you'll learn different approaches for including this kind of image quickly into your own web sites by using only a simple combination of basic markup and CSS styles, along with the assistance of PHP.
Introduction
Having already introduced you to the interesting terrain of developing noisy images, let me remind you of a few crucial topics that were covered in the second tutorial of the series. As you'll possibly recall, in that tutorial I showed you how to build the images in question by using an object-oriented approach. I used that approach specifically when it came to implementing the business logic required to generate random strings (remember that these were displayed in front of a tiny noisy background).
However, even when I initially went through the definition of a simple PHP class for handling the random values in a straightforward way, it must be admitted that the overall application lacked a crucial feature that makes it pretty useless when not properly implemented. As you'll remember, the corresponding random strings needed to be saved to a session variable. This was necessary so that they could be adequately verified on the web server after submitting the web form that originally included the noisy image.
As you can see, this characteristic is a must for this kind of application. Therefore, it needs to be properly addressed, in this case using the object-oriented paradigm. If you're not very familiar with working with classes and objects in PHP, fear not, because the random strings will be stored onto a session variable with the assistance of only one basic PHP class, which will handle this session-related process in a truly transparent way.
Hopefully, by the end of this series you'll have at your disposal a fully-functional noisy image application that simply uses a pair of basic PHP classes. The first one will be responsible for generating the required random values that will be included into the respective online form, and the second one will be tasked with saving these values to a session variable for further verification on the server.
Are you ready to tackle this last installment of the series and see how this noisy image application gets completed? Let's get started now!
Next: Reviewing the partial source code of the noisy image application >>
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