Passing data over web pages

[eduardoconsolacion]

Hello my name eduardo consolacion, i just want to ask some of your help to answer the question that i am longing to get it. Using PHP, I want to know how to pass a certain value or anything like it when you try to click a "picture of a book" or its "name" to be pass on another web page that will show the "book picture", the "price of the book" and the "description" of it? i do hope that you could help me with this? i would thank you in advance for everything. thank you again and have a pleasant day

[pbmods]

Heya, Eduardo. Welcome to TSDN!

The easiest way to do this is to pass your variables in the URL:

<a href="somepage.php?bookname=name+of+the+book"> ... </a>
 

And then in your PHP file, you can access the variables using the $_GET superglobal:

echo 'You picked the book entitled, "', $_GET['bookname'], '"';
 

For more information, check out this document.

[nathj]

Hi,

One thing to remember when passing data around like this, especially if it is in the query string (added to the end of the URL) is that it is user input and needs to be stested thoroughly before you use it.

I recommend checking that you have the data, then if you do , check that it is within the range of accepted values - so a numeric value is best for this.

In your case, assign each book a number and pass the number. Then you can check that the number has been set in the url and that it is within the define range. This allows you to handle any exceptions.

You can also check, via $_SERVER['HTTP_REFERER'], if the visitor has accessed the current page via the correct process. This will enable you to check if anyone is trying to get to extra page directly rather than via your pre-determined path.

Hopefully that will help to solve your problem and keep things nice and secure.

Cheers
nathj

[kovik]

You can also check, via $_SERVER['HTTP_REFERER'], if the visitor has accessed the current page via the correct process. This will enable you to check if anyone is trying to get to extra page directly rather than via your pre-determined path.

Do everything nathj said except for this part. HTTP_REFERER is handled client-side and can be altered and / or not sent at all. It's useful for some things (like highlighting search terms if a user comes from a search engine), but for anything that has to do with usability, security, or is *necessary*, you shouldn't bother with it.

[nathj]

Do everything nathj said except for this part. HTTP_REFERER is handled client-side and can be altered and / or not sent at all. It's useful for some things (like highlighting search terms if a user comes from a search engine), but for anything that has to do with usability, security, or is *necessary*, you shouldn't bother with it.

Hi Volectricity,

Thanks for the tip. I hadn't really thought about it like that.

Cheers
nathj