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Role: Documentation
Content type: text/plain
Description: Introduction to the package
Class: zbase32
Encode and decode data using zbase32 algorithm
Author: By
Last change:
Date: 12 years ago
Size: 2,750 bytes


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z-base32 encoding/decoding ========================== The purpose of 32-bit encoding generally is to put 8-bit data into streams that do not respect case. One typical example is e-mail addresses. Difference between base32 and z-base32 ====================================== z-base32 is more compact than standard base32, as it does not use pad characters. (These are in fact unnecessary for well-written algorithms.) z-base32 also favours characters that are visually distinct: z-base32 encodings can safely be transcribed over the telephone, for example. 5 bytes of 8-bit data will produce 8 bytes of z-base32-encoded data. Contents of this package ======================== There are two subdirectories in this package. One is for PHP version 5.2. It uses the zbase32 class wrapper to encapsulate the data needed for the encoding and decoding functions. The class has no instance data and no constructor: it does not make sense to create objects of type zbase32. The second is for PHP version 5.3. This uses namespaces rather than a class wrapper. This is more desirable, because an encoder/decoder is not a natural software object and does not lend itself to subclassing. Instead, the encoding/decoding functions are invoked using their qualified name, e.g. zbase32\encode($data). Each subdirectory contains a test program to ensure correct operation of the functions. If you choose to use the namespace version, you can ignore subdirectory 5.2; if you prefer not to get entangled with namespaces, ignore subdirectory 5.3. Using the functions =================== They are trivially easy to use. <?php // encoding using the 5.2 (class) version require 'zbase32.php'; $str = 'Some data'; $encoded_string = zbase32::encode($str); // get encoded data echo $encoded_string; // echoes 'kpzs43jyctozeae' // decoding using the 5.3 (namespace) version $str = 'jiose3jypfznytmqc7sgn5ur'; $decoded_string = zbase32\decode($str); echo $decoded_string; // echoes 'Made in England' ?> Author's rant ============= Before the advent of namespaces, classes were the principal method of packaging functionality in PHP, and keeping global objects out of the global namespace. Excessive use of classes can lead, however, to a loss of understanding of what classes are for: provision of encapsulated, extensible functionality. If it makes no sense to derive a subclass from an object, it makes sense to ask: "why make this functionality into an object in the first place?" The principal absurdity here is the "singleton" class. While the singleton pattern is valid and useful, there is something inappropriate about using classes to create an object that is global, unique and un-reusable. Isn't that what global data and functions are really for?