ch08
multiple pages, multiple files

From PHP Visual Quickstart Guide by Larry Ullman
Based on notes by Jack Davis (jcdavis@radford.edu)

External Files
- include('file.php');
  Generates a warning (but not an error) if the include fails (e.g. the file can't be found).
- require('file.php');
  Generates a fatal error (stopping entire execution) if the include fails (e.g. the file can't be found).
- In either case, the included file should also have its own <?php tags.

PHP Templates : Use included files to generate a coherent identity across all pages of a site:

home page — ch08-full-page.php
another page — ch08-albums.php
The source code of all the included files: homepage source code

Tip: end file names with “-inc.php” if they aren't standalone html files, but just fragments of a page meant to be included by others.

Tip: Minimize unmatched tags within an included file — it makes the fragments more re-usable in more contexts. Also, editing tools, parsers, etc. will be better able to work with those files. (For example, my editor's keyword-coloring and auto-indenting gets goofed up if I'm working with a inc file which has unmatched tags.)

So rather than:

<?php require('header-inc.php'); // This file includes '<html><head>..</head><body>', with dangling '<body>') ?>

<p>
  My page-specific content.
</p>

<?php require('footer-inc.php'); // This file ends with '<body><html>') ?>

use something like:

<?php require('doctype-inc.php'); ?>
<html>
  <?php require('header-inc.php'); // This file includes <head>...</head>') ?>
  <body>
    <?php require('page-top.php'); // This file includes a banner.) ?>

    <p>
      My page-specific content.
    </p>

  <?php require('footer-inc.php'); // This file includes contact-info ?>
  <body>
<html>

This practice is arguable, though; there is a price to shattering one page into too many included files. (E.g. for a high-performance site like amazon, you might be willing to trade-off poor design for efficiency.)

Also, it's nice to have the file for each page containing nothing more than one header/closer file without presuming any sort of page structure.

Though even in this case, consider using some framework to keep your page-source well organized/separated, and then write scripts to transform this into an efficient, optimized server arrangment. For example, each page's content might be entirely standalone frame, and the build system creates end files which combines that with header/footer/navigation files appropriately.

What if you want/need to nest requires?

Constants

define('CURRENCY','euros');

print CURRENCY;
print "468 CURRENCY";   # Just a string literal — won't print the value of the constant
print '468 ' . CURRENCY; # Will print the value of CURRENCY.

date Function
- date("Y.M.d (D) H:i.") returns the current date as something like “2011.Feb.03 (Thu) 00:13.”. You can also provide a date object (timestamp) as the second argument (e.g. date("Y.M.d (D) H:i.", filemtime(__FILE__))).
  - Y specifies year as 4 digits
  - M specifies month as 3 letters
  - D specifies day-of-month with leading 0s
  See the docs for other format options¹.
- A warning is generated if you use (rely on) the default time-zone of the server.
  You can bypass the warning by specifically setting the timezone , e.g. ini_set('date.timezone','America/New_York');
  This warning is generated because a change in server should be transparent (?).
Sticky Forms (self referencing)
register.php
Sending e-mail from a php script at RU
mail(to, subject, body); php program that can send an email
HTTP Headers
- header: create the http header.
- E.g. header('Location:page.php'); creates an http header to be returned to client, which will cause the client to redirect to page.php
- Must be called before anything is written to the php output file
- Header Function Example (Note: header instructs to forward after 10s.)
  One can also use the html header to specify the cache-expiration date of a page. (Helpful when appropriate — it lets browsers use cache in response to 'back' button.)

¹ Particularly cute: “F jS” for “December 4th” or “January 2nd”. ↩

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©2011, Ian Barland, Radford University
Last modified 2011.Apr.10 (Sun) Please mail any suggestions
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ch08 multiple pages, multiple files

ch08
multiple pages, multiple files