Miscellaneous problems with PHP

mborish_2000

Hello all,

I've made some posts on this forum before and everybody has been very helpful. I wish I could give something back but, unfortunately, I just can't get the gist of coding in general. My objective is to get this site that I have been farting around with for the past year working properly. I thought that I figured out everything I needed to know a few months ago, but basically I'm back because I've discovered larger, much more complicated problems 🙂

Here are my issues:

1.) I've underestimated the complexity of this IT stuff. I feel like I'm not learning things in the right order and wasting time. Stated simply, I don't know what the correct order to learn programing is or how to make graduated steps so that I keep building my knowledge in a reasonable amount of time. I've attended local PHP groups and some folks say start with Ruby on Rails, other say start learning the C language, and others say start with PHP. I've bought some books and feel like I understand the remedial concepts but have yet to find an applicable example I can emulate or way to apply the things I've learned to my objective.

2.) My learning environment might be less than Ideal. I have installed PHP and Apache as a localhost and have had mixed results. I feel that I configured the programs OK but am not sure if this is the best way to get started. Everyone at the PHP meetings I have attended like to execute stuff from the command line and use this PuTTy thing. Is this a better way to learn? Furthermore, some of my URL's take me out of localhost and onto my live stuff. I've found this matter frustrating.

3.) All of these other things keep getting in the way. I've found that in order to learn PHP, I need to know about Apache, .htaccess, .ini, PEAR and who else knows what.

Most of the working examples I've discovered are not complete or omit some very important piece of the puzzle. For example, the site I am striving to build is going to have markup, content, and presentation segrated, basically ideal OOP. One of the few working sites I know of sent me some code that looks like this:

<?php if($_SESSION[ 'pages' ][$id][0] != "0") { // if it's not a section 0 page ?>

<?php
if(!$id) {
include('nav/1.html');
} else {
include('nav/' . $_SESSION[ 'pages' ][$id][0] . '.html');
}
?>

</div>
<?php } ?>

<?php if(!$id || $id == 'home') {
include('content/home.html');
} else { ?>
<div id="content">
<?php if($SESSION[ 'pages' ][$id][2]) { // this is a sub-page
include('content/' . $SESSION[ 'pages' ][$id][2] . "/" . $id . '.html');
} else if( $month ) { // this is an archive
include( 'content/' . $id . '/' . $month . '.html' );
} else {
if (file_exists( 'content/' . $id . '.html' )) {
include( 'content/' . $id . '.html' );
} else {
include( 'content/404.html' );
}
} ?>

</div>
<?php } ?>

<?php include('nav/footer.html'); ?>

</div>

I understand everything that is going on here except for the most important part: how the global session[ 'pages' ] variables figure out what page to grab, and why the sub arrays? are numbered [0], [1], and [2] respectively. I'm sure that there is another page to it, and I've found another post here that has a somewhat similar example, but I still can't put all of the pieces together. How are the damn $id's called? The URL's output stuff like: http://www.isphpforme.com/?id=docs&f=1

If you surf the web enough, eventually all of the coding experts contradict each other. Some folks say that you should not include get variables in your URL's while others say it's fine and that Googlebot as well as its friends will index your page properly. Assuming that I can solve my earlier problems, Is it a huge pain in the butt to use strict OOP, completely eliminate redundancy, and have pretty URL's that look like http://www.isphpforme.com/thesolution/download/

Sorry this turned our really long.

-Mike

sneakyimp

you might try 'php for dummies'. if you are having trouble getting the gist of programming that might be a good start.

The IT stuff can be quite complicated....installing and all that. I was very fortunate in that I had access to a good sys admin when i was learning PHP. he took care of all the hardware and stuff so i could focus on the php. if you must do all the IT stuff too it will make learning harder but you will ultimately be a better programmer for it.

as for experts contradicting each other and building OOP stuff that is free of redundancy, yes of course that happens all the time.

try starting with something simple and build from there. if you want to do something in particular, see if you can find an open source project that does what you want and start there. reading other people's code is a great way to learn.

greenie2600

mborish_2000 -

Everyone learns differently. Choose the path that works for you. If you find that a particular approach isn't getting you anywhere, try a different approach.

Personally, I'd say the best way to learn PHP is to study PHP, rather than some other language. Academic computer science folks learn everything in terms of C, but unless you're interested in academic computer science, stick with the problem at hand.

Most developers code in the environment you've described: with Apache, PHP, and MySQL running on their workstation. In large code shops, they sometimes have a dedicated development server, but that's far from necessary.

These days, there are enough point-and-click tools available that the command line is strictly optional. Many PHP geeks swear by the Linux CLI, but I rarely touch it myself. If you find it useful, use it. If you don't, don't.

As for links on your dev site taking you to the live site: it sounds like you're using absolute URLs (e.g., http://www.example.com/myfile.html) in your links. Use root-relative links (e.g., /myfile.html) whenever possible; if you must include the site's domain in a URL, define it as a constant in your config.php, and build those URLs dynamically.

Strictly speaking, this is server administration stuff, not PHP stuff. If you're maintaining your own server (even on your own workstation), you do need to know a little about it - but once you get things set up and configured, you should rarely have to touch it.
Without knowing the context, it's impossible to know exactly how this site is intended to work. The use of the indices 0, 1, and 2 for different elements of the 'pages' array is arbitrary; the programmer devised their own schema for this array. The session variables being retrieved here are set on another page, so if this code is all you have to look at, you'd have to apply some deductive reasoning to figure out what they mean (in effect, reverse-engineering the schema). (This is not an ideal implementation, by the way.)
I think you're confusing OOP with some unrelated things. OOP has nothing to do with pretty URLs or separation of content and presentation. It can certainly be used for that purpose, but so can ordinary procedural programming.

Including variables in the querystring is fine, with two caveats:

a. Some search engines won't index URLs with querystrings. As you mention, you can get around this by presenting altered URLs to the client that look like discrete files. However, this involves editing Apache's httpd.conf file (or using .htaccess files).

b. You should generally use the POST method for forms. This is because GET is limited to 1,024 characters, and can result in forms being double-posted (if users click the "Back" button in their browser).

Feel free to ask for clarification on any of this...

mborish_2000

Thanks for the help so far everybody!

4. Without knowing the context, it's impossible to know exactly how this site is intended to work. The use of the indices 0, 1, and 2 for different elements of the 'pages' array is arbitrary; the programmer devised their own schema for this array. The session variables being retrieved here are set on another page, so if this code is all you have to look at, you'd have to apply some deductive reasoning to figure out what they mean (in effect, reverse-engineering the schema). (This is not an ideal implementation, by the way.)

Well, what's the correct way to get files from a directory using PHP? If I've got 50 different pages and if each page has a unique identifier, how should I call it? Basically what I'm getting at is this:

I see tons of URL's that have http://www.isphpforme.com/?id=docs. I know that $id = docs.php or something equvalent. I also know that docs.php only contains general text that you would find in the body of the html page, and everything else, like header, footer, and nav is left alone or is on another php page. Is there a simple way to write this so that I don't have to duplicate information if I add a new page body?

I'm having a devil of a time figuring out how to manage my web content with just one or two root php pages and have all of the non redundant content pulled in from other files. I'm not interested in rewriting the same content 20 or so times like I did on my last project.

-Mike

twilliamsen

I tell you what..

I am a network admin and we use all microsoft technologies. Granted they are great, but hard to understand sometimes.

As far as creating quick apps that are powerful and fast, i love the combo of

apache/PHP/mySQL. The speed comparision against IIS/ASP/MSSQL is that the apache/PHP/mysql will run circles around it.

Now, this is the real reason why I chose the above.

works on ANY platform
easier to deploy and get up and running
Really easy to learn versus ASP.NET

greenie2600

mborish_2000 -

Ah, I see what you are trying to do now. You want to have a single template file that pulls in different content, based on a variable in the querystring. correct?

<?php

// retrieve the ID from the querystring
$id = $_GET["id"];

// convert this to a filename
// you might want to do this by querying against a database,
// using ID as a key, but for now we'll just assume that the
// filename is the ID plus a ".php" extension

$filename = $id . ".php";

// retrieve the contents of the file
$file_contents = file_get_contents( $filename );

// write them to the client
echo $file_contents;

?>

Or you could do it all on one line:

echo file_get_contents( $_GET["id"] . ".php" );

This will work fine, but users might also be able to view .php files that you don't want them to (such as your config file, containing the database password) by entering their own values for "id" in the querystring. So you'd probably want to make this a little more secure - for example, by putting all your content files in a subdirectory, and adjusting this code so it will only pull files from that directory.

mborish_2000

Thanks greenie 2600. I'm glad that you understand what I'm talking about. So. bas you're suggesting: file_get_contents( 'content/' . $_GET["id"] . ".html" ); and

if($_SERVER['REQUEST_METHOD'] != "GET"){
echo("Unauthorized attempt to access page.");
exit;
}

Now, this may sound stupid, but how do I call different pages with <a href= ></a>

greenie2600

Yup, that should work - although it's not necessary to check the REQUEST_METHOD server variable to make sure it's GET, for two reasons:

The code never does anything with the POST data anyway, so there's no way a user could exploit this architecture by supplying fabricated POST data.
You may want to implement forms within content pages that use the POST method. Blocking POST submissions would make this impossible.

Simply isolating the content files in their own directory should provide all of the protection you need.

To link to pages, just do something like this:

<a href="?mypage.php">Click Here</a>

One last thought: you'll probably want to check that the file exists before trying to write it to the client, so you can display a friendly "Page Not Found" error to the user instead of a PHP error. You can use the file_exists() function for this.