====== Module Index ======

===== Module Tiers =====

LEAST modules are classified by risk and centrality:

^ Tier ^ Modules ^ Risk level ^
| Tier 1 — Platform Core | libgeneral, libdb, liblogin, libdatetime, libengine, libmenu, libdashboard | Highest — used by everything |
| Tier 2 — Business Core | libassociation, libcollection_admin, libcollection_use, liblesson, libprimary | High — core business logic |
| Tier 3 — Secondary | quiz, discussion, course, keyring, educator tools | Medium |
| Tier 4 — Specialised | mindfulwriting, family, rollcall, logictree, openbadge, entrepreneur, slack | Lowest — isolated |

===== Core Modules =====

==== libgeneral ====
The most-used module. ''fn_Gen_*'' functions are called everywhere. Includes:
  * ''fn_Gen_PageStart()'' / ''fn_Gen_PageEnd()'' — page wrapper
  * ''fn_Gen_Array_GetValue()'' / ''fn_Gen_Array_SetValue()'' — array helpers
  * ''fn_Gen_HasData()'' — safe array check
  * ''fn_T()'' — translation/localisation (most-called function in the platform)
  * Engine array rendering system

==== libdb ====
All database access flows through here:
  * ''fn_Db_GenericSQLRead_Array()'' — read query returning PHP array
  * ''fn_Db_GenericSQLExecute()'' — write query execution
  * ''fn_Db_CreateArray()'' / ''fn_Db_CreateInsertIgnoreSQL()'' — insert helpers
  * ''fn_Db_ScrapeInput()'' — input sanitisation (always use this before writing user input)

==== liblogin ====
Authentication and session management:
  * ''fn_Login_ValidateLogin()'' — standard auth gate
  * ''fn_Login_Admin_ValidateLogin()'' — admin auth gate (Level 3 required)
  * ''fn_Login_ValidateLogin_Generic()'' — underlying auth implementation

==== libassociation ====
Association management and permissions:
  * ''fn_Association_Security()'' — the main permission check function
  * ''fn_Association_PermissionProcess()'' — grant/revoke permissions
  * ''fn_Association_NoPermissionBlock()'' — renders "access denied" message
  * ''fn_Db_AssocMember()'' — membership check

==== libcollection_admin / libcollection_use ====
Collection engine administration and end-user display:
  * Admin: create/edit collections, fields, views, actions
  * Use: display records, handle interactions, render swim lanes

==== liblesson ====
Lesson and material management:
  * ''fn_Lesson_Manage()'' — lesson CRUD
  * ''fn_Lesson_Materials_*()'' — material attachment
  * ''fn_Lesson_Progress_*()'' — learner progress tracking

===== Key Global Variables =====

^ Variable ^ Set by ^ Purpose ^
| ''$objGlobal_ODBC'' | const_db.php | Global MySQL connection |
| ''$intGlobal_LoginId'' | fn_Login_ValidateLogin() | Current user's ID |
| ''$aryGlobal_Login'' | fn_Login_ValidateLogin() | Current user's full record |
| ''$strGlobal_AssociationRef'' | Request URL | Current association context |
| ''$strGlobal_Master_IncludePath'' | Entry page | Path to /lib/ |
| ''$aryZLeastSettings'' | fn_db_data.php | ZLEASTSettings table (global config) |

===== Request Flow =====

Every page request follows:

<code>
Browser → Entry Page → const_globals.php → fn_standard_library.php
  → fn_Login_ValidateLogin() → Domain Aggregator → Domain Functions
  → DB reads/writes → HTML render → fn_standard_close.php
</code>

See the [[developer:start|Developer Guide]] for API and integration flows.