Overview

Below are notes I (zaufi) wrote during code Tiki core prototype. You may see the source code in $(CVSROOT)/tests/core.

Implementing Tiki Core Prototype

System Init

• The main purpose is to initialize 'low level' components during core construct... It is like runlevel startup scripts in linux
• Initialization sequence can be extended by adding scripts into init.scripts directory
  • Name of script file should have the following format: NN-name.php, where NN is a 2 digits used to define execution order
  • 00-name.php is executed first; 99-name.php is executed last
• Typical examples of such scripts:
  • add include pathes for PHP
  • database connectivity and low level init
  • inherit and make smarty instance
• All of above will replace tiki-db.php (with local.php), setup.php and some (most? -terence) parts of tiki-setup_base.php/tiki-setup.php into well organised and logicaly independed ordered execution scripts

Tiki Objects Tree

• All objects in Tiki organized in the Tree
• Every node of the Tiki Objects Tree (TOT) have associated ACL (Access Control List)
• Unique key of the object in Tiki system is the pair of objectID and objectType
• Object type should be registered by special API
  • ID of object type assigned by programmer — not by the system (because objectType should remain the same after registering/unregistering)
• Any object in system should be in the Tree, else it is impossible to determinate ACL for that object
• core objectTypes like user and group cannot be unregistered
• There is API to manage objects in the Tree
  • Object Types API
    • register/unregister object type
    • list registered object types
    • check if given object type registered
  • Objects Management
    • add/remove object from the Tree
    • get/set parent for object
    • get/set 1st level childs for object
  • Rights (Permission) Management
    • grant/revoke one object's right to perform an action on another object
    • check if given an object has a certain right
    • examples of actions: read/write/lock/delete/undo/upload, etc.
    • not all actions apply to each object; some objects are not even "active"
• Consider using phpGACL as 'low level' layer

Core Object Types

• 'Core object types' mean that it is impossible to unregister such object types and they are exists just after installation. They are exists always ('till system exists 😊.
• There is attributes of 'object type' entity in Tiki
  • object_type — numbered ID assigned by programmer
  • name — human readable name
  • description — hint what is this type is.
  • can_contain — list of object types which can be contained (be child) of instances of this object type
• List of 'core' objects ...
  [+]
  • User
    • Entity represent a user of Tiki system
    • Attributes
      [+]
      • ID
      • login name
      • full name
      • description
      • email
      • smth else?
  • Group
    • Entity represent a group of users of Tiki system
    • Attributes
      [+]
      • ID
      • name
      • description
      • list of members — maybe this is separate table or just special formatted text field (like serialized array of <objectid,objecttypes>)
  • Container
    • Object the with the only purpose: be container for ALL other objects (nested containers are OK)
    • Attributes
      [+]
      • ID
      • name
      • description
  • Extension
    • Represent Tiki Extension
    • Attributes
      [+]
      • ID
      • name
      • description
      • handle file — file with class
      • handle class — class name defined in 'handle file' which is implement extension (child of TikiExtension class)
      • version
      • about text
      • is installed flag — i.e. is installation script was executed for this extension
      • is enabled flag — i.e. is extension enabled by admin
      • smth else?
• Maybe sometimes in future we will implement full featured 'Tiki Object Schema' with inheritance relations among Object Types... 😊

Core objects

• by default the only object of type 'User' is present... it called 'admin' — user with default password and admin rights on TOT top (root).
• another bunch of 'default' Tiki Objects is a core 'Extensions' objects like
  • Admin interface
  • Extension to handle User objects
  • Extension to handle Group objects
  • Extension to handle Container objects
  • Maybe 'Workplace Layout and Theme Control' can be extension(s) too 😊
• To make 'core objects' uninstallable it is enough not to provide corresponding scripts so system can't invoke it and can't remove this extensions 😊 — just a little trick — of couse admin interface will show this like 'uninstallable extensions'
• Default location of all objects is a top of the Tiki Objects Tree

Extensions Management

• Lifecycle of Tiki Extension
  [+]
  1. to be availalable to Tiki system extension should be placed to special directory (let it be tiki/ext)
  2. then admin can execute installation script for such extension — it should be named install.php (and uninstall.php) and be located in root of extension dir
     • if no script found then extension can't be installed/uninstalled — core extension use this fact... so no other magic here 😊
     • usual things happens during installation is
       • register extension in core (mandatory)
       • register page(s) (URL) which is belongs to extension
       • register custom object types
       • extend rights (ACO) list
       • check dependencies (i.e. is some other extensions installed)
       • creating some tables in DB
       • add/change some records in some tables
     • can installation have dialog boxes? 😊 — windowz users call this 'wizards' 😊
  3. to be visble for users at first admin should enable extension (later it can be disabled and still remains installed)
  4. next, admin may grant corresponding rights to users
  5. after priod of usage extensions may be disabled ...
  6. ... and uninstalled (if uninstall.php present)
  7. during usage period extension also may be updated to newer version (by using update.php)
• What registering of extension is?
  • It is the way to tell what an extension is ready to be enabled and configured — i.e. all installation procedures done and extension can be used
  • actualy happened: add record into 'extensions' table with the following info
    • main extension file name (i.e. mymegacoolextension.php)
    • extension class name
      • should be child of TikiExtension core class
    • version info (number?) — can be asked from class
    • description text (to display in interface) — can be asked from class
    • smth else?
• What is the registering of page is?
  • assume that extension register page (URL) like 'tiki-name.php'... this mean that core should create such file and place inclusion of core files and make a call to extension after some checks...
  • ... also extension needs to provide method name core should call if this page requested ...

... 2b continue ...