Grav Lifecycle

It is often useful to know how Grav processes in order to fully understand how best to extend Grav via plugins. This is the Grav lifecycle:

index.php

Check PHP version to ensure we're running at least version 7.1.3
Class loader initialization
Obtain Grav instance
Grav.php
1. No instance exists, so call load()
2. Add loader
3. Add and initialize debugger
4. Add grav (deprecated)
5. Register Default Services
6. Register Service Providers
  1. Accounts Service Provider
    1. Add permissions (1.7)
    2. Add accounts (1.6)
    3. Add user_groups (1.7)
    4. Add users (deprecated)
  2. Assets Service Provider
    1. Add assets
  3. Backups Service Provider
    1. Add backups (1.6)
  4. Config Service Provider
    1. Add setup
    2. Add blueprints
    3. Add config
    4. Add languages
    5. Add language
  5. Error Service Provider
    1. Add error
  6. Filesystem Service Provider
    1. Add filesystem
  7. Flex Service Provider
    1. Add flex (1.7)
  8. Inflector Service Provider
    1. Add inflector
  9. Logger Service Provider
    1. Add log
  10. Output Service Provider
    1. Add output
  11. Pages Service Provider
    1. Add pages
    2. Add page
  12. Request Service Provider
    1. Add request (1.7)
  13. Scheduler Service Provider
    1. Add scheduler (1.6)
  14. Session Service Provider
    1. Add session
    2. Add messages
  15. Streams Service Provider
    1. Add locator
    2. Add streams
  16. Task Service Provider
    1. Add task
    2. Add action
  17. Simple Service Providers
    1. Add browser
    2. Add cache
    3. Add events
    4. Add exif
    5. Add plugins
    6. Add taxonomy
    7. Add themes
    8. Add twig
    9. Add uri
call Grav::process()
Grav.php
1. Run Initialize Processor
  1. Configuration
    1. Initialize $grav['config']
    2. Initialize $grav['plugins']
  2. Logger
    1. Initialize $grav['log']
  3. Errors
    1. Initialize $grav['errors']
    2. Registers PHP error handlers
  4. Debugger
    1. Initialize $grav['debugger']
  5. Handle debugger requests
  6. Start output buffering
  7. Localization
    1. Set the locale and timezone
  8. Plugins
    1. Initialize $grav['plugins']
  9. Pages
    1. Initialize $grav['pages']
  10. Uri
    1. Initialize $grav['uri']
    2. Add $grav['base_url_absolute']
    3. Add $grav['base_url_relative']
    4. Add $grav['base_url']
  11. Handle redirect
    1. Redirect if system.pages.redirect_trailing_slash is true and trailing slash in URL
  12. Accounts
    1. Initialize $grav['accounts']
  13. Session
    1. Initialize $grav['session'] if If system.session.initialize is true
2. Run Plugins Processor
  1. Fire onPluginsInitialized event
3. Run Themes Processor
  1. Initialize $grav['themes']
  2. Fire onThemeInitialized event
4. Run Request Processor
  1. Initialize $grav['request']
  2. Fire onRequestHandlerInit event with [request, handler]
  3. If response is set inside the event, stop further processing and output the response
5. Run Tasks Processor
  1. If request has attribute controller.class and either task or action:
    1. Run the controller
    2. If NotFoundException: continue (check task and action)
    3. If response code 418: continue (ignore task and action)
    4. Else: stop further processing and output the response
  2. If task:
    1. Fire onTask event
    2. Fire onTask.[TASK] event
  3. If action:
    1. Fire onAction event
    2. Fire onAction.[ACTION] event
6. Run Backups Processor
  1. Initialize $grav['backups']
  2. Fire onBackupsInitialized event
7. Run Scheduler Processor
  1. Initialize $grav['scheduler']
  2. Fire onSchedulerInitialized event
8. Run Assets Processor
  1. Initialize $grav['assets']
  2. Fire onAssetsInitialized event
9. Run Twig Processor
  1. Initialize $grav['twig']
    Twig.php
    
    Set Twig template paths based on configuration
    
    Handle language templates if available
    
    Fire onTwigTemplatePaths event
    
    Fire onTwigLoader event
    
    Load Twig configuration and loader chain
    
    Fire onTwigInitialized event
    
    Load Twig extensions
    
    Fire onTwigExtensions event
    
    Set standard Twig variables (config, uri, taxonomy, assets, browser, etc)
10. Run Pages Processor
  1. Initialize $grav['pages']
    Pages.php
    
    Call buildPages()
    
    (logic differs somewhat for Flex Pages, but the idea is the same)
    
    Check if cache is good
    
    If cache is good load pages date from
    
    If cache is not good call recurse()
    
    Fire onBuildPagesInitialized event in recurse()
    
    If a .md file is found:
    
    Page.php
    
    Call init() to load the file details
    
    Set the filePath, modified, id
    
    Call header() to initialize the header variables
    
    Call slug() to set the URL slug
    
    Call visible() to set visible state
    
    Set modularTwig() status based on if folder starts with _
    
    Fire onPageProcessed event
    
    If a folder found recurse() the children
    
    Fire onFolderProcessed event
    
    Call buildRoutes()
    
    Initialize taxonomy for all pages
    
    Build route table for fast lookup
  2. Fire onPagesInitialized event with [pages]
  3. Fire onPageInitialized event with [page]
  4. If page is not routable:
    1. Fire onPageNotFound event with [page]
  5. If task:
    1. Fire onPageTask event with [task, page]
    2. Fire onPageTask.[TASK] event with [task, page]
  6. If action:
    1. Fire onPageAction event with [action, page]
    2. Fire onPageAction.[ACTION] event with [action, page]
11. Run Debugger Assets Processor
  1. Debugbar only: Add the debugger CSS/JS to the assets
12. Run Render Processor
  1. Initialize $grav['output']
  2. If output instanceof ResponseInterface:
    1. Stop further processing and output the response
  3. Else:
    1. Render page with Twig's processSite() method
      
      Twig.php
      
      Fire onTwigSiteVariables event
      
      Get the page output
      
      Fire onTwigPageVariables, also called for each modular subpage
      
      If a page is not found or not routable, first fire the onPageFallBackUrl event to see if we have a fallback for a media asset and then fire onPageNotFound if not
      
      Set all Twig variables on the Twig object
      
      Set the template name based on file/header/extension information
      
      Call render() method
      
      Return resulting HTML
    2. Fire onOutputGenerated event
    3. Echo the output into output buffer
    4. Fire onOutputRendered event
    5. Build Response object
    6. Stop further processing and output the response
13. Fire onPageHeaders event to allow page header manipulation
14. Output HTTP header and body
15. Render debugger (if enabled)
16. Shutdown
  1. Close session
  2. Close connection to client
  3. Fire onShutdown event

Whenever a page has its content() method called, the following lifecycle occurs:

Page.php

If content is NOT cached:
1. Fire onPageContentRaw event
2. Process the page according to Markdown and Twig settings. Fire onMarkdownInitialized event
3. Fire onPageContentProcessed event
Fire onPageContent event

Grav Lifecycle

index.php

Grav.php

Grav.php

Twig.php

Pages.php

Page.php

Twig.php

Page.php

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