I am making website and this website will have more than 20pages. I am using my template to add a webpage. This template has header and footer, so I just add the body of new page. But, what if I want to change navigation bar in the header, then I have to change all 20 pages that I already made to correct. I want to know better way. I read a book, and it says about "php include" function. Should I use this function in the header and footer of each webpage to call header and footer file? If I want to change the navigation bar in the header, all I can do is changing only one header file, then rest of website will be changed.
Is this correct way? In this case, what do you do? I am a beginner, so please advise me. Thank you in advance.
You should build your website as following. The header.html would contain the navigation.
header.html
<!doctype html>
<html>
<head>
...
</head>
<body>
<nav>
...
</nav>
footer.html
<footer>
...
</footer>
</body>
</html>
page.php
<?php
require_once 'header.html';
?>
Your content goes here
<?php
require_once 'footer.html';
?>
You should use require_once so the header and footer will be imported only once per script and if the header or footer cant be found, the script will throw an exception and stop the "application".
"require_once" and "require" are language constructs and not functions. Therefore they should be written without "()" brackets!
Yes this is the correct way or you could just copy your header and footer code to every .html file (if you don't like PHP)
Yes, this is the correct way. Try to think of the DRY principle - don't repeat yourself. Elements of your web page that are common across multiple pages can be coded once, then called in. If you need to update these elements, you update them once and it affects all pages.
You then "include" these elements into your page, and the elements are self contained files. As a basic example you would have header.php
<html>
<head><!-- all of your head meta tags in here--></head>
<body>
<div id="header"><!--your header elements and top menu in here --></div>
and footer.php:
<div id="footer"><!-- your footer elements in here--></div>
</body>
</html>
Don't forget in both header and footer files you can then put dynamic code if you wish. Then for each of your pages you would simply call these files in using include, include_once, require or require_once
<?php
include('header.php');
//this is where your actual page content goes
include('footer.php');
?>
A very basic example, but hopefully that makes sense to you.
Correct.
If you include another php file it will calculate/ask for input/do output (whatever you do in the file) as part of your main file.
If you include a php file that has a function you can later call this function without it showing in your main file. (Saves space in your main file)
So your 20 pages may only need a few lines of body text and the rest is header and footer. This will make changes very easy