====== Core Overview ======

This is a walk through the source code during a request for ''/doku.php?id=start&do=show'' to explain the basics of DokuWiki. You should have the full source available when reading this to fully enjoy this journey. Use the [[https://codesearch.dokuwiki.org/xref/dokuwiki/|XRef]] links to obtain a browsable version of the source. There is also a more detailed [[callgraph]] page available including the rendering process. A lot of detail is left out of this description to make it simpler.

^ Filename                           ^ Code snippet                                       ^ Description                                                                                                                                                                                                                            ^
| [[xref>doku.php]]                  | '' if(!defined('DOKU_INC'))       ''               | Everything starts here by defining the base code directory                                                                                                                                                                             |
| :::                                | '' $ACT = $_REQUEST['do']         ''               | next we determine which action is requested a.k.a. [[devel:action_modes|do modes]]                                                                                                                                                     |
| :::                                | '' require_once('init.php')       ''               | over to init.php, initialize core                                                                                                                                                                                                      |
| [[xref>inc/init.php]]              | '' include('preload.php')         ''               | [[preload]] make it possible to override directories and configuration cascade                                                                                                                                                         |
| :::                                | '' if(!defined('DOKU_CONF')       ''               | create [[devel:environment]] defines for code location                                                                                                                                                                                 |
| :::                                | '' include(DOKU_INC. 'inc/config_cascade.php') ''  | prepare and load the global [[configuration]] file(s)                                                                                                                                                                                  |
| :::                                | '' global $lang;                  ''               | load and prepare the [[devel:localization|language]] files using English for all missing entries                                                                                                                                       |
| :::                                | '' if(!defined('DOKU_REL')        ''               | create all [[devel:environment]] defines not already defined, which might be dependent of the [[:config]] settings                                                                                                                     |
| :::                                | '' if(!headers_sent() && ..       ''               | init session and set cookie                                                                                                                                                                                                            |
| :::                                | '' require_once (DOKU_INC.'inc/load.php') ''       | [[autoloader|autoload]] all libraries                                                                                                                                                                                                  |
| :::                                | '' ... \\ auth_setup() \\ ...     ''               | initialize plugin controller, [[events|event handling]] system, authentication and exit after setting up mail                                                                                                                          |
| [[xref>doku.php]]                  | '' $ID    = getID()               ''               | back from init.php, sanitize and turn request into [[devel:environment|global variables]]                                                                                                                                              |
| :::                                | '' $INFO = pageinfo()             ''               | add page [[devel:metadata]] into a [[devel:environment|global variable]], this includes calling [[xref>auth_quickaclcheck()]] and [[xref>p_get_metadata()]]. The later causing a rendering of page metadata if it isn't cached.        |
| :::                                | '' if(!$INFO['exists'] ...        ''               | send 404 for missing pages                                                                                                                                                                                                             |
| :::                                | '' trigger_event(DOKUWIKI_STARTED)''               | call [[action plugins]] subscribing the [[devel:event:dokuwiki_started|DOKUWIKI_STARTED]] event                                                                                                                                        |
| [[xref>inc/actions.php]]           | '' act_dispatch($ACT)             ''               | do the work depending on [[devel:action_modes|action]]                                                                                                                                                                                 |
| :::                                | ''%%if ($evt->advise_before()) ...%%''             | allow plugins to override default behavior using [[devel:event:action_act_preprocess|ACTION_ACT_PREPROCESS]] event                                                                                                                     |
| :::                                | '' $ACT = act_clean($ACT)         ''               | sanitize and redirect [[config:disableactions|disabled actions]] into ''do=show''                                                                                                                                                      |
| :::                                | '' ... \\ $ACT = act_permcheck($ACT) \\ ...  ''    | call processing code for requested action(s) while checking needed ACL permissions. The $ACT might change during [[xref>act_dispatch()]].                                                                                              |
| :::                                | '' global $INFO \\ global $conf              ''    | make global variables accessible to template code                                                                                                                                                                                      |
| :::                                | '' trigger_event(ACTION_HEADERS_SEND)        ''    | call [[action plugins]] subscribing the [[devel:event:action_headers_send|ACTION_HEADERS_SEND]] event                                                                                                                                  |
| :::                                | '' include(template('main.php'))             ''    | over to the selected template main script                                                                                                                                                                                              |
| [[xref>lib/tpl/dokuwiki/main.php]]  | '' ... \\ tpl_metaheaders() \\ ...    ''           | the [[template]] main script consist of HTML design elements calling on php methods for content like metaheaders, buttons, breadcrumb navigation elements etc. all available in the [[xref>inc/template.php]] file                     |
| :::                                | '' tpl_content()                      ''           | here the actual wiki page is created                                                                                                                                                                                                   |
| [[xref>inc/template.php]]          | :::                                                | :::                                                                                                                                                                                                                                    |
| :::                                | '' trigger_event(TPL_ACT_RENDER)      ''           | call to [[xref>tpl_content_core()]] using [[devel:event:tpl_act_render|TPL_ACT_RENDER]] event                                                                                                                                          |
| :::                                | '' switch($ACT)                       ''           | select content based on action, the basic ''do=show'' calls [[xref>html_show()]]                                                                                                                                                       |
| [[xref>inc/html.php]]              | '' $html = p_wiki_xhtml(...)          ''           | which uses a [[devel:caching#two-stage-caching|cached XHTML]] version of the page __OR__ triggers the [[parser|renderer]] to render cached instructions as XHTML __OR__ use the [[parser]] to turn wiki text into instructions first.  |
| [[xref>inc/template.php]]          | '' trigger_event(TPL_CONTENT_DISPLAY) ''           | back in [[xref>tpl_content()]] [[action plugins|action plugin's]] have a last chance to edit raw HTML before output by using [[devel:event:tpl_content_display|TPL_CONTENT_DISPLAY]] event                                             |
| [[xref>doku.php]]                  | '' trigger_event(DOKUWIKI_DONE)   ''               | finish by calling [[action plugins]] subscribing the [[devel:event:dokuwiki_done|DOKUWIKI_DONE]] event when the template main script has ended                                                                                         |