HTML 4 Website - User submits email address to access/download a file - php

Question

We have an archaic website done completely in HTML 4, and I've been tasked with coming up with a way to have the user input their email address to access/download files.
After submitting their email address, it can either take them directly to the pdf file or be redirected to a "Thank You" page that has a link to the file.
We would then be able to see a list of the email addresses & who downloaded what.
I was told server side scripting language is required. To be honest, I have basic skills in coding, and I am completely stumped by this task. Any help (explained in simple terms please) would be greatly appreciated.
Thank you!
Jen

Answer 1

Your solution is going to be broken down into 2 parts, both server-side. Firstly, you will need some server-side code to handle the user input, and a database to store a mapping from email addresses to file names (although this can just be a text file sitting on the server).
Server-side script
You have a world of choices when it comes to server-side scripting languages, from the insanely popular PHP, which while supported from the majority of web-hosting companies, is riddled with bad design problems and (to my mind) should be avoided at all costs. However, it is still completely adequate for your purposes.
On the other end of the scale is the lightning fast node.js, which allows you to program your web application using JavaScript; this is arguably a more pleasant means to do so, but hosting is typically more expensive and geared towards web applications with large user bases.
There are many other possible solutions in between, but for argument's sake we'll assume you use PHP.
Database
The role of the database is simply to store the relationship between the email addresses and their respective file download paths. Again, there are a whole host of different solutions, and some may argue for or against them. One of the least-trusted solutions (but unfortunately, incredibly widely supported and tightly knit with PHP) is MySQL, which again for argument's sake, we'll use.
How it works
Your web application will first of all check for any user input (i.e. the user's email address submitted from an HTML form). Then:
If the user has not submitted anything, then output a page with an HTML form on it, which might look something like this:
<form action="thispage.php" method="post">
<input type="text" name="email" value="Enter your address here" />
<input type="submit" value="Get my file!" />
</form>
When the user clicks the submit button, the entered email address will be sent to thispage.php (or whatever you decide to call this script).
If the user has submitted an email address, (i.e. the user clicked the button in the above form), then we query the database with the email address to find out where the user's file is. There are a million-and-one tutorials on how to do this - there are straightforward examples for PHP here.
Once the file path has been retrieved from the database, you can either output some HTML as a 'Thank you!' page, with a link to the PDF file, or simply redirect them immediately by using the following code, where $URL is the URL of the file.
<?php
header('Location: ' . $URL);
?>
There are again alternatives to how you do this - if you want to keep the PDF file hidden from unauthorised eyes, you can store it somewhere on the server, inaccessible to the outside world, and then simply output the contents of the file into the page. This might look something like the following, where $path is the path to the PDF file on the server's filesystem:
<?php
header('Content-type: application/pdf');
echo file_get_contents($path);
?>
I hope this gets you started. If you need any more guidance, you're already in the right place to ask!

Answer 2

It depends on how much protection you want. If you want to make sure the file is completely inaccessible for people who don't input their e-mail address, you can block the file with the .htaccess file (in Apache). Then make a page to retrieve the file to download if the session that you previously set up was okay. I don't think that would be necessary from what you said. The other option is to make a page with a simple form, with action="somepage.php". On that page you would then retrieve the e-mail with $_GET or $_POST (that is, if you are using PHP), then save it in the database or a text file or something. (You could even send it to your e-mail) Then:
1) If you are using the protection I mentioned before, then set the session as OK (you can do this with session_start() at the beginning of the file and then include $_SESSION["gave_email"] = 'true';). Then test that variable to see if it is true. If it is true, redirect the user to the PHP page that shows the file. (The appropriate syntax for a check like this one might look like this:
(if isset($_SESSION["gave_email"] && $_SESSION["gave_email"] == true)
//you show the content, then reset the $_SESSION variable to false
2) If you are not worried about security, then simply redirect the user to the page you want (either directly to the file or to another page that contains a link for download).
To forward with PHP you can use header('Location: page.php'), where page.php is the page you want. The whole thing seems pretty simple, so if you have some more specific question in this, please ask it.

Answer 3

Try google feedburner. Its allow you to valid download verification When someone subscribe on your website using feedburner then download will be possible. The feedburner subscription is refresh in every 10 hour.
http://feedburner.google.com/