Chapter 3: A 10,000 - Foot View of CodeIgniter
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CodeIgniter includes the following libraries:Benchmarking — The Benchmarking library is always active. Use it to determine the time
difference between any two marked points in code and to calculate memory usage.Calendaring — The Calendaring library must be loaded by a controller. Use it to dynamically
create calendars for given months and years, with some control over formatting and appearance.Config — The Config library is initialized automatically by the system. Use it to retrieve
configuration information.Database — The Database library is a very powerful set of methods that must be loaded. You ’ ll
be using this library so much that the next subsection of this chapter focuses on it exclusively.Email — The Email library must be loaded. It includes a very powerful set of tools that simplifies
the job of sending e - mails.Encryption — The Encryption library must be loaded. It provides you with powerful two - way
encryption methods.File Uploading — The File Uploading library must be loaded. Use this library whenever you need
to handle file uploads. It includes powerful validation features that can restrict a file by mime
type, size (in kilobytes), or even image dimensions.FTP — The FTP library must be loaded. Use this library to transfer files to a remote server (only
standard FTP is supported, by the way).HTML Table — The HTML Table library must be loaded. Use this very versatile library to
autogenerate HTML tables from arrays or database result sets.Image Manipulation — The Image Manipulation library must be loaded. Use it to resize images,
create thumbnails, crop or rotate images, and watermark images. Some functions require further
PHP support (such as GD/GD2).Input and Security — The Input and Security library must be loaded. Use it to pre - process input
data (from forms and URLs) and to handle some security functions (such as guarding against
XSS attacks).Language — The Language library must be loaded. Use this library to load different sets of
language files for internationalization.Loader — The Loader library is automatically loaded. You will use this library primarily to load
views with your controller, but it is also used to load libraries.Output — The Output library is automatically loaded. This library has one main function: Send
the finalized web page to the requesting browser. It is also used for caching.Pagination — The Pagination library must be loaded. Use this labor - saving library to paginate
database results for performance and usability. You can control how many records to display per
page, how many records to pull from the database, and the look and feel of different parts of the
pagination.Session — The Session library must be loaded. Use CodeIgniter ’ s Session library to maintain
state information about a user. This library does not use PHP ’ s built - in sessions — instead, it
generates its own session data. Because this library is so important, a separate subsection of this
chapter is devoted to it.