PHP within a variable

kaiyatamaya

The main problem I have with learning php is that I know exactly what I want to do but no idea what it's called or how to do it, and so googling for info on it, searching forums like this or looking it up in the docs is impossible (I've been browsing here for over an hour already). So if you know what this process below is called, please let me know so I can go a-searching for it! 😃

I'm working on a php driven site where the pages are very simple entries into tables of the theme:

page_id
page_title
page_content
page_date

i.e. everything on the page is in page_content. Now, the site uses a lot of queries - pretty much every page has a query on it somewhere, if not a couple. However I can't work out how to get php within page_content to be parsed on the page. If I write the following for page_content (i.e. the value of the variable page_content is the following):

html html html bla more html

<?php
echo "Is this workin?";
?>

lots of html more html etc

That line of PHP simply sits there in the source, unparsed and unloved.

Is it even possible to include PHP within a variable that is produced by a PHP driven page? Am I doing this a horribly inefficient way?

Many thanks!

_theworks

i think you mean dynamic content? try googling "creating a dynamic website php and mysql" or somthing like that..

thorpe

Yes it is possible, use the [man]eval/man function to parse php contained in variables. Be aware though, that eval is considered to be a fairly dangerous function. If any user input can make it to eval then a user could possibly inject php scripts into your site and bring down the whole thing.

A general rule of thumb is, if you need to use eval to do something, your probably doing it the wrong way.

babyfat

Well, I'm just beginning to learn PHP as well, but I thought I'd share this web site with you. I just completed this tutorial and it did help some.

http://www.rci.rutgers.edu/~jfulton/php1/

HTH

FatalError

thorpe wrote:
A general rule of thumb is, if you need to use eval to do something, your probably doing it the wrong way.

Not really, I use it all the time, and big sites and forum systems like phpBB use it. However, like thorpe said, it's a dangerous function, and you should only use it when you know what's going through it.

kaiyatamaya

Thanks for your replies!

thorpe wrote:
A general rule of thumb is, if you need to use eval to do something, your probably doing it the wrong way.

The follow up question is an obvious one 😉 If eval is the wrong way, what's the right way?

kaiyatamaya

I'm guessing there is no right way?

Weedpacket

Depends on what the something you're doing is.

thorpe

Depends on what the something you're doing is.

Yeah, I suppose my warning may have been a bit of overkill, but I am trying to get the point across that it can be dangerous.

darkerstar

I think your idea is more of a CMS. Go to
http://www.opensourcecms.com/

Most of the CMS are free, you can download them and learn how they work.

kaiyatamaya

Thanks 🙂

I'm guessing that my solution is to stick with my current method; separate php pages for all dynamic pages, but to try and streamline it a bit. It's not the most efficient in terms of updating but I know it's secure, and at my current level of knowledge I can't risk doing something wrong with eval and opening my site up.

I have tried several CMS's and portals - the site I'm making isn't article driven, blog, authors, etc - none of that is required. However it is heavy on the queries - it runs off about 15 tables of information. I have found in the past that using CMS's forces me to make sacrifices and compromises on the function of my site - i.e. having to use established modules like forums, articles etc in place of custom functions.

My site as it is (many tables, many php pages, many scripts) works perfectly - exactly how I wanted it to. The only point of trying to use something like eval would be to make my upkeep of it easier.

Thanks for your help!