In this article I'll try to describe how to develop a very simple Content Management System (CMS). I've chosen PHP as the server-side scripting language and MySQL as the database management system purely because I think they are fairly easy to use and they do the job very well.
I won't spend any time describing CMSs, what they are, or why you should or should not use them as there are plenty of excellent articles on this site that describe them perfectly well. I'll just explain one way of developing one.
This CMS consists of a single web page (index.php) that can have its contents updated by use of a standard form (updatePage.htm). The contents entered via the form are stored in a database, and are accessed and displayed by the web page. Although this CMS is too simple to be of any real use, it could be used as the starting point for a real life CMS solution. In subsequent articles I'll look at various ways to extend the CMS to make it more useful.
There are four files in this project:
cms.sql
updatePage.htm
updatePage.php
index.php
cms.sql
This file creates a database called cms, and creates a table in that database called page. It also loads some intial data into the table. You only need to use this file once.
updatePage.htm
This web page contains a simple form that can be used to enter the contents displayed by index.php.
updatePage.php
This is the form handler - the script that processes the data (entered in updatePage.htm) and inserts it into the database table (page).
index.php
This is the web page that displays the data held in the database table.
You can download a zip file containing these four files from http://www.computernostalgia.net/downloads/cms_v1.zip
cms.sql
1. CREATE DATABASE cms;
2. USE cms;
3. CREATE table page (
4. pageID integer auto_increment,
5. contents text,
6. primary key (pageID)
7. );
8. insert into page (pageID, contents) values ('1', 'dummy text');
Line 1 creates a database called cms in the MySQL database management system.
Line 2 tells MySQL to use the database for the subsequent commands.
Line 3 creates a table in the database.
Line 4 creates a column called pageID, which will contain integers, and which will be automatically incremented as new records are added to the table. As we only have one web page (index.php) in our imaginary website, we will only have one record and therefore one integer: 1. If we added additional pages to the table, they would be automatically numbered (2, 3, 4, etc).
Line 5 creates a second column called contents, which will contain text. This is where the editable contents displayed by index.php will be stored.
Line 6 sets pageID as the primary key, which you can think of as a reference for the table. As we only have one table, which will contain only one record, we won't make any use of the key. I've included it though because it's good practice to do so.
Line 7 simply closes the bit of code that was started in line 3.
Line 8 inserts some intial data into the table: 1 as the first (and only) pageID, and 'dummy text' as the contents of the first record.
updatePage.htm
(Note that for display considerations, I've inserted spaces into the HTML tag names, otherwise they would be processed as HTML code.)
1. <>
2. <>
3. <>Really Simple CMS< /title >
4. < /head >
5. <>
6. <>Really Simple CMS< /h1 >
7. < name="form1" method="post" action="updatePage.php">
8. Enter page content:<>< rows="10" cols="60" name="contents">< /textarea >
9. < type="submit" name="Submit" value="Update Page">
10. < /form >
11. < /body >
12. < /html >
This is just standard HTML, which probably doesn't really need explaining. All it does is present a form, the contents of which are sent to updatePage.php when the 'Update Page' button is clicked.
updatePage.php
1. < ?php 2. $contents=$_REQUEST['contents']; 3. mysql_connect("localhost", "root", "password"); 4. $result = @mysql_query("UPDATE cms.page SET contents='$contents'"); 5. mysql_close(); 6. ? >
This is the form handler, that's to say, the script that processes the data entered into the form (in updatePage.htm).
Line 1 signifies the start of a PHP script.
Line 2 requests the contents that were posted from the form. We could have written
$contents=$_POST['contents']; instead if we had wanted to.
Line 3 connects to the MySQL database server, setting up the host name, which I've assumed to be localhost, the database user, which I've assumed to be root, and the password needed to connect to the database. I have no idea what this would be for your system so I've just written the word password.
Line 4 updates the page table in the cms database with the new contents.
Line 5 closes the database connection.
Line 6 closes the PHP script.
index.php
1. <>
2. <>
3. <>Home Page< /title >
4. <>
5. <>Home Page< /h1 >
6. < ?php 7. mysql_connect("localhost", "root", "password"); 8. $result = mysql_query("select contents from cms.page"); 9. while ($row = mysql_fetch_assoc($result)){ 10. $contents = $row['contents']; 11. } 12. echo $contents; 13. ? >
14. < /body >
15. < /html >
This is the web page that displays the contents from the database. It's called index.php rather than index.htm because the web page contains PHP code. If the page was called index.htm, the PHP preprocessor, which is part of the web server, would not know that the page contained PHP code, and would therefore not try to process the script part of the page (lines 6 to 13). This would cause the script itself to be displayed in the browser rather than the HTML generated by the script.
Most of the lines in this web page are pretty straight forward and don't need explaining. Lines 6 to 13 contain the PHP script that extracts the contents from the database and displays (echos) it in the browser.
Installing/Running the CMS
To use the CMS you need to copy the files onto your web server into the area allocated for web pages. Your web server needs to support PHP and MySQL; if it doesn't, the CMS won't work.
You also need to use the correct database connection names and passwords (those used in the mysql_connect lines in the PHP scripts).
Exactly how you run the cms.sql file to set up the database and database table will vary from web server to web server so it's difficult to give precise instructions here. If you have a phpMyAdmin icon or something similar in your web servers control/administration panel you should be able to use that.
Once you've set up the database and table, you can simply browse to the updatePage.htm web page and update the database contents. You can then browse to the index.php page to view the updates.
If you have any problems or comments regarding the CMS, please email me at johndixon@computernostalgia.net and I'll be pleased to assist you if possible.
By John Dixon
