CodeIgniter User Agent Configuration Arrays | Generated by AI
Overview
This PHP code snippet is part of the CodeIgniter framework (a PHP web framework), specifically from the User Agent Class configuration file. It defines four arrays ($platforms, $browsers, $mobiles, and $robots) that map user agent string fragments to human-readable names for browsers, operating systems, mobile devices, and web crawlers/bots. The code is used to parse and identify the type of device, browser, or bot visiting a website based on the HTTP User-Agent header sent by clients.
The arrays are associative (key-value pairs), where keys are partial strings from user agent strings (case-insensitive matches), and values are the corresponding display names. CodeIgniter’s User Agent library uses these for detection, such as determining if a visitor is on Android, using Chrome, or is a search bot.
$platforms Array
This array identifies operating systems or platforms. The keys are substrings that might appear in the User-Agent header, and values are clean names for display.
- Example entries:
'windows nt 10.0'→'Windows 10''android'→'Android''os x'→'Mac OS X'
- Purpose: Helps detect the client’s OS (e.g., Windows, iOS, Linux) for analytics, content customization, or feature tweaks.
- Note: Order matters for accuracy, as some substrings might overlap (e.g.,
'windows'is a catch-all at the end).
$browsers Array
Identifies web browsers. Browsers often report multiple identifiers, so the order prioritizes subtypes first (as per the comment).
- Example entries:
'Chrome'→'Chrome''MSIE'→'Internet Explorer''Firefox'→'Firefox'- Special case:
'Opera.*?Version'(regex-like match) for modern Opera that reports as “Opera/9.80” with a version.
- Purpose: Determines the browser (e.g., Chrome, Safari) to serve browser-specific features or redirects.
- Regex note: Some keys use basic regex patterns (e.g.,
.*?for wildcard matching), handled in the library.
$mobiles Array
Maps user agent flags for mobile devices, phones, and related devices/browsers. It’s larger and includes phones, tablets, game consoles, and fallback categories.
- Structured sections:
- Phones/Manufacturers:
'iphone'→'Apple iPhone','samsung'→'Samsung'. - Operating Systems:
'android'→'Android','symbian'→'Symbian'. - Browsers:
'opera mini'→'Opera Mini','fennec'→'Firefox Mobile'. - Other/Fallback:
'mobile'→'Generic Mobile'for unmatched mobile indicators.
- Phones/Manufacturers:
- Purpose: Flags mobile devices for responsive design, mobile-only features, or app redirects. Includes legacy entries (some commented out as outdated).
$robots Array
Lists common web crawlers and bots. Keys are substrings from bot user agents.
- Example entries:
'googlebot'→'Googlebot''bingbot'→'Bing''yandex'→'YandexBot'
- Purpose: Identifies crawlers for SEO handling, like serving different content to bots (e.g., no ads) or logging bot traffic.
Usage in CodeIgniter
- The User Agent Class loads this file and uses methods like
is_browser(),is_mobile(),is_robot(), andplatform()to parse the User-Agent string. - It performs case-insensitive searches through these arrays to match keys against the string.
- For discrepancies (e.g., new devices/browsers not listed), you’d update these arrays manually or via community extensions.
Additional Notes
- Security: This is purely for data collection; it doesn’t execute harmful code. User-Agent strings can be spoofed, so don’t rely on this for critical security checks.
- Updates: CodeIgniter versions may have added/modified entries; this looks like an older snapshot (e.g., Edge as ‘Spartan’ is outdated).
- How to test: In a PHP script, you could load this and use
strposor regex to match against a sample User-Agent string.
If you provide a specific part or have a question about implementation, let me know!