Core Components

Core Components

System Classes (sys/)

1. Interface.php (sys/Interface.php)

• Purpose: Smarty template engine wrapper
• Extends: Smarty
• Key Methods:
  • __construct() - Sets up template directories, registers functions
  • assign() - Assign variables to templates
  • display() - Render template

2. VFSession.php (sys/VFSession.php)

• Purpose: Session management for VuFind
• Extends: DSession
• Singleton Pattern: VFSession::instance()
• Key Methods:
  • instance() - Get/create session instance
  • (Inherits from DSession: set, get, delete, is_set)

3. DSession.php (sys/DSession.php)

• Purpose: Database-backed session storage
• Storage: MySQL sessions table
• Key Features:
  • UUID-based session IDs
  • HttpOnly secure cookies
  • Automatic session expiration
  • Data serialization
• Key Methods:
  • singleton() - Get/create session
  • set($var, $val) - Store data
  • is_set($var, $val) - Check existence
  • get($var) - Retrieve data
  • delete($var) - Remove data
  • write() - Persist to database
  • kill() - Destroy session

4. Solr.php (sys/Solr.php)

• Purpose: Solr search interface
• Key Methods:
  • __construct($host, $index) - Connect to Solr
  • simplesearch($query) - Execute search
  • standardSearchComponents() - Construct Solr query
  • getRecord($id) - Fetch single record

5. SolrConnection.php (sys/SolrConnection.php)

• Purpose: HTTP client for Solr
• Uses: HTTP_Request2 (PEAR)
• Key Methods:
  • send($url) - Execute HTTP request
  • Response parsing and error handling

6. HTStatus.php (sys/HTStatus.php)

• Purpose: HathiTrust user access status
• Data Source: HTstatus cookie (set by Shibboleth SSO)
• Key Properties:
  • $logged_in - Boolean
  • $institution_code - Institution identifier
  • $auth_type - Authentication method
  • $emergency_access - Emergency access flag
  • $mapped_institution_code - Mapped institution for consortia

7. GeoIP.php (sys/GeoIP.php)

• Purpose: IP geolocation
• Database: MaxMind GeoIP2
• Key Methods:
  • ip_to_iso($ip) - Get country code from IP

8. RecordUtils.php (services/Record/RecordUtils.php)

• Purpose: Record-specific business logic
• Key Methods:
  • Access determination
  • Rights interpretation
  • Format detection
  • URL generation

Service Controllers (services/)

Pattern: Action Class

All controllers (service/Record/Record.php and service/Search/Home.php) extend the base Action class. The base Action class is a PEAR-derived stub whose only method is an empty launch(); every service action is expected to override launch (or run its workflow on construction).

services/Record/Record.php keeps the action inside the constructor instead of overriding launch, instantiating a record immediately normalizes the incoming id/mergesearch parameters (including redirects/404s or merged-item shortcuts), records the default tab, and wires $interface with session metadata and the configured search engine before pulling the MARC data.

Once the raw record is retrieved, it is assigned to Smarty, decorated with summary/link data, similar records, subjects, legacy URLs, and the MDL flag so the templated view can render the “record” page without any further controller logic; helpers like getEditions() and getLinkNums() keep per-record enrichment localized.

services/Search/Home.php follows the more conventional action pattern: launch() calls setup() to build the SearchStructure, session, and the Solr connection, then decides whether module/action parameters are present.

• If so, it sets the page title and invokes search(); otherwise, it renders the static home page.
• search() acts as the main workflow: it primes Smarty with sort/search/session/facet metadata, enforces pagination limits, calls newprocessSearch() to run the backend query, handles no-results/error cases, enriches each hit with MARC/title/link data, caches the query in a cookie, and finally displays the list template after populating facet counts.
• The supporting methods newprocessSearch() and getFacetCounts() encapsulate the Solr call and facet aggregation so search() can remain a clean orchestration point.

services/Search/

• Home.php - Search results page
• Advanced.php - Advanced search form
• Reserves.php - Course reserves
• Suggest.php - Autocomplete suggestions
• SearchExport.php - RSS feed generation
• Error.php - Error action

services/Record/

• Home.php - Record display
• Export.php - Citation export formats
• RecordUtils.php - Record utility functions . . .