1. Getting Started
      1. Video Quick-Start Series
      2. Server Requirements
        1. MySQL 5.0.51 Issues
      3. Installation
        1. Basic Installation
          1. MODx Revolution on Debian
          2. Problems with WAMPServer 2.0i
          3. Lighttpd Guide
          4. Installation on a server running ModSecurity
          5. MODX and Suhosin
          6. Nginx Server Config
        2. Successful Installation, Now What Do I Do?
        3. Successful Installation, Now What Do I Do?
        4. Advanced Installation
        5. Git Installation
        6. Command Line Installation
          1. The Setup Config Xml File
        7. Troubleshooting Installation
        8. Using MODx Revolution from SVN
      4. An Overview of MODX
        1. Glossary of Revolution Terms
          1. Explanation of Directory Structure
        2. Roadmap
        3. MODX Revolution Framework Structure Ideology
        4. What's New in 2.3
    2. FAQs & Troubleshooting
      1. CMP Development FAQs & Troubleshooting
    3. Making Sites with MODX
      1. Structuring Your Site
        1. Resources
          1. Content Types
          2. Named Anchor
          3. Static Resource
          4. Symlink
            1. Using Resource Symlinks
          5. Weblink
        2. Templates
        3. Chunks
        4. Using Snippets
      2. Tag Syntax
      3. Customizing Content
        1. Template Variables
          1. Creating a Template Variable
          2. Adding a Custom TV Type - MODX 2.2
          3. Bindings
            1. CHUNK Binding
            2. DIRECTORY Binding
            3. EVAL Binding
            4. FILE Binding
            5. INHERIT Binding
            6. RESOURCE Binding
            7. SELECT Binding
          4. Template Variable Input Types
          5. Template Variable Output Types
            1. Date TV Output Type
            2. Delimiter TV Output Type
            3. HTML Tag TV Output Type
            4. Image TV Output Type
            5. URL TV Output Type
          6. Adding a Custom TV Input Type
          7. Adding a Custom TV Output Type
          8. Creating a multi-select box for related pages in your template
          9. Accessing Template Variable Values via the API
        2. Properties and Property Sets
        3. Input and Output Filters (Output Modifiers)
          1. Custom Output Filter Examples
      4. Commonly Used Template Tags
        1. Date Formats
    4. Administering Your Site
      1. Settings
        1. System Settings
          1. access_category_enabled
          2. date_timezone
          3. access_context_enabled
          4. access_resource_group_enabled
          5. allow_duplicate_alias
          6. allow_forward_across_contexts
          7. allow_multiple_emails
          8. allow_tags_in_post
          9. archive_with
          10. automatic_alias
          11. auto_check_pkg_updates
          12. auto_check_pkg_updates_cache_expire
          13. auto_menuindex
          14. base_help_url
          15. blocked_minutes
          16. cache_action_map
          17. cache_context_settings
          18. cache_db
          19. cache_db_expires
          20. cache_db_session
          21. cache_default
          22. cache_disabled
          23. cache_format
          24. cache_handler
          25. cache_json
          26. cache_json_expires
          27. cache_lang_js
          28. cache_lexicon_topics
          29. cache_noncore_lexicon_topics
          30. cache_resource
          31. cache_resource_expires
          32. cache_scripts
          33. cache_system_settings
          34. clear_cache_refresh_trees
          35. compress_css
          36. compress_js
          37. concat_js
          38. container_suffix
          39. cultureKey
          40. custom_resource_classes
          41. default_per_page
          42. default_template
          43. editor_css_path
          44. editor_css_selectors
          45. emailsender
          46. emailsubject
          47. enable_dragdrop
          48. error_page
          49. extension_packages
          50. failed_login_attempts
          51. feed_modx_news
          52. feed_modx_news_enabled
          53. feed_modx_security
          54. feed_modx_security_enabled
          55. fe_editor_lang
          56. filemanager_path
          57. filemanager_path_relative
          58. filemanager_url
          59. filemanager_url_relative
          60. forgot_login_email
          61. friendly_alias_lowercase_only
          62. forward_merge_excludes
          63. friendly_alias_max_length
          64. friendly_alias_restrict_chars
          65. friendly_alias_restrict_chars_pattern
          66. friendly_alias_strip_element_tags
          67. friendly_alias_translit
          68. friendly_alias_translit_class
          69. friendly_alias_translit_class_path
          70. friendly_alias_trim_chars
          71. friendly_alias_urls
          72. friendly_alias_word_delimiter
          73. friendly_alias_word_delimiters
          74. friendly_urls
          75. friendly_url_prefix
          76. friendly_url_suffix
          77. global_duplicate_uri_check
          78. hidemenu_default
          79. link_tag_scheme
          80. mail_charset
          81. mail_encoding
          82. mail_smtp_auth
          83. mail_smtp_helo
          84. mail_smtp_hosts
          85. mail_smtp_keepalive
          86. mail_smtp_pass
          87. mail_smtp_port
          88. mail_smtp_prefix
          89. mail_smtp_single_to
          90. mail_smtp_timeout
          91. mail_smtp_user
          92. mail_use_smtp
          93. manager_date_format
          94. manager_direction
          95. manager_favicon_url
          96. manager_language
          97. manager_lang_attribute
          98. manager_theme
          99. manager_time_format
          100. context_tree_sort
          101. context_tree_sortby
          102. context_tree_sortdir
          103. session_enabled
          104. upload_files
          105. modx_charset
          106. new_file_permissions
          107. new_folder_permissions
          108. password_generated_length
          109. password_min_length
          110. phpthumb_allow_src_above_docroot
          111. phpthumb_cache_maxage
          112. phpthumb_cache_maxfiles
          113. phpthumb_cache_maxsize
          114. phpthumb_cache_source_enabled
          115. phpthumb_document_root
          116. phpthumb_error_bgcolor
          117. phpthumb_error_fontsize
          118. phpthumb_error_textcolor
          119. phpthumb_far
          120. phpthumb_imagemagick_path
          121. phpthumb_nohotlink_enabled
          122. phpthumb_nohotlink_erase_image
          123. phpthumb_nohotlink_text_message
          124. phpthumb_nohotlink_valid_domains
          125. phpthumb_nooffsitelink_enabled
          126. phpthumb_nooffsitelink_erase_image
          127. phpthumb_nooffsitelink_require_refer
          128. phpthumb_nooffsitelink_text_message
          129. phpthumb_nooffsitelink_valid_domains
          130. phpthumb_nooffsitelink_watermark_src
          131. phpthumb_zoomcrop
          132. principal_targets
          133. proxy_auth_type
          134. proxy_host
          135. proxy_password
          136. proxy_port
          137. proxy_username
          138. publish_default
          139. rb_base_dir
          140. rb_base_url
          141. request_controller
          142. request_param_alias
          143. request_param_id
          144. resource_tree_node_name
          145. resource_tree_node_tooltip
          146. richtext_default
          147. search_default
          148. server_offset_time
          149. server_protocol
          150. session_cookie_domain
          151. session_cookie_lifetime
          152. session_cookie_path
          153. session_cookie_secure
          154. session_handler_class
          155. session_name
          156. settings_version
          157. signupemail_message
          158. site_name
          159. site_start
          160. site_status
          161. site_unavailable_message
          162. site_unavailable_page
          163. strip_image_paths
          164. symlink_merge_fields
          165. tree_default_sort
          166. tree_root_id
          167. tvs_below_content
          168. udperms_allowroot
          169. ui_debug_mode
          170. unauthorized_page
          171. upload_maxsize
          172. use_alias_path
          173. use_browser
          174. use_editor
          175. use_multibyte
          176. welcome_screen
          177. which_editor
          178. which_element_editor
          179. xhtml_urls
      2. Using Friendly URLs
      3. Contexts
        1. Creating a Subdomain from a Folder using Virtual Hosts
        2. Using One Gateway Plugin to Manage Multiple Domains
      4. Customizing the Manager
        1. Customizing the Manager via Plugins
        2. Form Customization Profiles
        3. Form Customization Sets
          1. Customizing Tabs via Form Customization
          2. MODX GitHub Contributor's Guide
        4. Manager Templates and Themes
      5. MODX GitHub Integrator's Guide
      6. Security
        1. Hardening MODX Revolution
        2. Policies
          1. ACLs
          2. Permissions
            1. Permissions - Administrator Policy
            2. Permissions - Resource Policy
          3. PolicyTemplates
        3. Resource Groups
        4. Roles
        5. Security Standards
        6. Security Tutorials
          1. More on the Anonymous User Group
          2. Creating a Second Super Admin User
          3. Giving a User Manager Access
          4. Making Member-Only Pages
          5. Restricting an Element from Users
        7. Troubleshooting Security
          1. Resetting a User Password Manually
        8. User Groups
        9. Users
      7. Installing a Package
        1. Troubleshooting Package Management
      8. Upgrading MODX
        1. Upgrading to Revolution 2.0.5
        2. Upgrading from 2.0.x to 2.1.x
        3. Upgrading from Versions Earlier than 2.0.5
        4. Upgrading to 2.2.x
        5. Upgrading to Revolution 2.0.0-rc-2
        6. Troubleshooting Upgrades
        7. Upgrading from MODx Evolution
          1. Functional Changes from Evolution
      9. Moving Your Site to a New Server, or to Root from Subfolder
      10. Media Sources
        1. Adding a Media Source
        2. Assigning Media Sources to TVs
        3. Media Source Types
          1. Media Source Type - File System
          2. Media Source Type - S3
        4. Securing a Media Source
          1. Creating a Media Source for Clients Tutorial
      11. Dashboards
        1. Assigning a Dashboard to a User Group
        2. Creating a Dashboard Widget
        3. Dashboard Widget Types
          1. Dashboard Widget Type - File
          2. Dashboard Widget Type - HTML
          3. Dashboard Widget Type - Inline PHP
          4. Dashboard Widget Type - Snippet
        4. Managing Your Dashboard
    5. Developing in MODX
      1. Code Standards
      2. Overview of MODX Development
        1. Developer Introduction
          1. Getting Started Developing
        2. Extras Directories
        3. Setting up a Development Environment
      3. Basic Development
        1. Static Elements
        2. Plugins
          1. System Events
            1. OnMODXInit
            2. OnFileManagerBeforeUpload
            3. OnFileManagerDirCreate
            4. OnFileManagerDirRemove
            5. OnFileManagerDirRename
            6. OnFileManagerFileCreate
            7. OnFileManagerFileRemove
            8. OnFileManagerFileRename
            9. OnFileManagerFileUpdate
            10. OnPackageInstall
            11. OnPackageUninstall
            12. OnPackageRemove
            13. OnBeforeCacheUpdate
            14. OnBeforeChunkFormDelete
            15. OnBeforeChunkFormSave
            16. OnBeforeDocFormDelete
            17. OnBeforeDocFormSave
            18. OnBeforeEmptyTrash
            19. OnBeforeManagerLogin
            20. OnBeforeManagerLogout
            21. OnBeforeManagerPageInit
            22. OnBeforePluginFormDelete
            23. OnBeforePluginFormSave
            24. OnBeforeSaveWebPageCache
            25. OnBeforeSnipFormDelete
            26. OnBeforeSnipFormSave
            27. OnBeforeTempFormDelete
            28. OnBeforeTempFormSave
            29. OnBeforeTVFormDelete
            30. OnBeforeTVFormSave
            31. OnBeforeUserActivate
            32. OnBeforeUserFormDelete
            33. OnBeforeUserFormSave
            34. OnBeforeWebLogin
            35. OnBeforeWebLogout
            36. OnCacheUpdate
            37. OnCategoryBeforeRemove
            38. OnCategoryBeforeSave
            39. OnCategoryRemove
            40. OnCategorySave
            41. OnChunkBeforeRemove
            42. OnChunkBeforeSave
            43. OnChunkFormDelete
            44. OnChunkFormPrerender
            45. OnChunkFormRender
            46. OnChunkFormSave
            47. OnChunkRemove
            48. OnChunkSave
            49. OnContextBeforeRemove
            50. OnContextBeforeSave
            51. OnContextFormPrerender
            52. OnContextFormRender
            53. OnContextRemove
            54. OnContextSave
            55. OnDocFormDelete
            56. OnDocFormPrerender
            57. OnDocFormRender
            58. OnDocFormSave
            59. OnDocPublished
            60. OnDocUnPublished
            61. OnEmptyTrash
            62. OnFileManagerUpload
            63. OnHandleRequest
            64. OnInitCulture
            65. OnLoadWebDocument
            66. OnLoadWebPageCache
            67. OnManagerAuthentication
            68. OnManagerLogin
            69. OnManagerLoginFormPrerender
            70. OnManagerLoginFormRender
            71. OnManagerLogout
            72. OnManagerPageAfterRender
            73. OnManagerPageBeforeRender
            74. OnManagerPageInit
            75. OnPageNotFound
            76. OnPageUnauthorized
            77. OnParseDocument
            78. OnPluginBeforeRemove
            79. OnPluginBeforeSave
            80. OnPluginEventRemove
            81. OnPluginFormDelete
            82. OnPluginFormPrerender
            83. OnPluginFormRender
            84. OnPluginFormSave
            85. OnPluginRemove
            86. OnPluginSave
            87. OnPropertySetBeforeRemove
            88. OnPropertySetBeforeSave
            89. OnPropertySetRemove
            90. OnPropertySetSave
            91. OnResourceGroupBeforeRemove
            92. OnResourceGroupBeforeSave
            93. OnResourceGroupRemove
            94. OnResourceGroupSave
            95. OnRichTextBrowserInit
            96. OnRichTextEditorInit
            97. OnRichTextEditorRegister
            98. OnSiteRefresh
            99. OnSiteSettingsRender
            100. OnTemplateVarBeforeRemove
            101. OnTemplateVarBeforeSave
            102. OnTemplateVarRemove
            103. OnTemplateVarSave
            104. OnUserActivate
            105. OnUserBeforeRemove
            106. OnUserBeforeSave
            107. OnUserChangePassword
            108. OnUserFormDelete
            109. OnUserFormSave
            110. OnUserNotFound
            111. OnUserRemove
            112. OnUserSave
            113. OnWebAuthentication
            114. OnWebLogin
            115. OnWebLogout
            116. OnWebPageComplete
            117. OnWebPageInit
            118. OnWebPagePrerender
        3. Snippets
          1. Adding CSS and JS to Your Pages Through Snippets
          2. How to Write a Good Chunk
          3. How to Write a Good Snippet
          4. Templating Your Snippets
        4. xPDO
      4. Advanced Development
        1. Caching
          1. Setting up Memcache in MODX
        2. Custom Manager Pages
          1. Custom Manager Pages in 2.3
          2. Actions and Menus
            1. Action List
          3. Custom Manager Pages Tutorial
          4. MODExt
            1. MODx.combo.ComboBox
            2. MODx.Console
            3. MODx.FormPanel
            4. MODx.grid.Grid
            5. MODx.grid.LocalGrid
            6. MODx.msg
            7. MODx.tree.Tree
            8. MODx.Window
            9. MODExt Tutorials
              1. 1. Ext JS Tutorial - Message Boxes
              2. 2. Ext JS Tutorial - Ajax Include
              3. 3. Ext JS Tutorial - Animation
              4. 4. Ext JS Tutorial - Manipulating Nodes
              5. 5. Ext JS Tutorial - Panels
              6. 7. Ext JS Tutoral - Advanced Grid
              7. 8. Ext JS Tutorial - Inside a CMP
            10. MODExt MODx Object
        3. Custom Resource Classes
          1. Creating a Resource Class
            1. Creating a Resource Class - Step 2
            2. Creating a Resource Class - Step 3
            3. Creating a Resource Class - Step 4
        4. Extending modUser
        5. From the Command Line (CLI)
        6. Internationalization
          1. Adding a Translation
        7. MODX Services
          1. modFileHandler
          2. modMail
          3. modRegistry
        8. Namespaces
        9. Package Management
          1. Package Dependencies
          2. Creating a 3rd Party Component Build Script
          3. Providers
          4. Transport Packages
        10. Using runProcessor
        11. Validating Requests: Tokens and Nonces
        12. Developing RESTful APIs
      5. Other Development Resources
        1. Summary of Legacy Code Removed in 2.1
        2. API Reference
        3. Class Reference
          1. modResource
            1. modResource.isMember
          2. modChunk
            1. modChunk.getContent
            2. modChunk.setContent
          3. modUser
            1. modUser.addSessionContext
            2. modUser.changePassword
            3. modUser.endSession
            4. modUser.getSessionContexts
            5. modUser.getSettings
            6. modUser.hasSessionContext
            7. modUser.isAuthenticated
            8. modUser.isMember
            9. modUser.loadAttributes
            10. modUser.removeSessionContext
            11. modUser.removeSessionContextVars
            12. modUser.removeSessionCookie
          4. modX
            1. modX.addEventListener
            2. modX.checkForLocks
            3. modX.checkSession
            4. modX.executeProcessor
            5. modX.getAuthenticatedUser
            6. modX.getCacheManager
            7. modX.getChildIds
            8. modX.getChunk
            9. modX.getConfig
            10. modX.getContext
            11. modX.getEventMap
            12. modX.getLoginUserID
            13. modX.getLoginUserName
            14. modX.getParentIds
            15. modX.getParser
            16. modX.getPlaceholder
            17. modX.getRegisteredClientScripts
            18. modX.getRegisteredClientStartupScripts
            19. modX.getRequest
            20. modX.getResponse
            21. modX.getService
            22. modX.getSessionState
            23. modX.getTree
            24. modX.getUser
            25. modX.getVersionData
            26. modX.handleRequest
            27. modX.hasPermission
            28. modX.initialize
            29. modX.invokeEvent
            30. modX.lexicon
            31. modX.makeUrl
            32. modX.parseChunk
            33. modX.regClientCSS
            34. modX.regClientHTMLBlock
            35. modX.regClientScript
            36. modX.regClientStartupHTMLBlock
            37. modX.regClientStartupScript
            38. modX.reloadConfig
            39. modX.removeAllEventListener
            40. modX.removeEventListener
            41. modX.runProcessor
            42. modX.runSnippet
            43. modX.sendError
            44. modX.sendErrorPage
            45. modX.sendForward
            46. modX.sendRedirect
            47. modX.sendUnauthorizedPage
            48. modX.setDebug
            49. modX.setPlaceholder
            50. modX.setPlaceholders
            51. modX.switchContext
            52. modX.toPlaceholder
            53. modX.toPlaceholders
            54. modX.unsetPlaceholder
            55. modX.unsetPlaceholders
        4. Loading MODX Externally
        5. Reserved Parameters
    6. Case Studies and Tutorials
      1. Developing an Extra in MODX Revolution
        1. Developing an Extra in MODX Revolution, Part II
        2. Developing an Extra in MODX Revolution, Part III
      2. Developing an Extra in MODX Revolution - MODX 2.1 and Earlier
        1. Developing an Extra in MODX Revolution, Part II - MODX 2.1 and Earlier
        2. Developing an Extra in MODX Revolution, Part III - MODX 2.1 and Earlier
      3. PHP Coding in MODx Revolution, Pt. I
        1. PHP Coding in MODx Revolution, Pt. II
        2. PHP Coding in MODx Revolution, Pt. III
      4. Using Custom Database Tables in your 3rd Party Components
      5. Creating a Blog in MODx Revolution
      6. Loading Pages in the Front-End via AJAX and jQuery Tabs
      7. Reverse Engineer xPDO Classes from Existing Database Table
      8. Integrating a Template into MODX Tutorial
      9. Quick and Easy MODX Tutorials
        1. Automated Server-Side Image Editing
      10. Adding Custom Fields to Manager Forms
      11. Create a Multilingual Website with migxMultiLang
      12. Managing Resources and Elements via SVN
    7. MODX Community Information
      1. Becoming a Core Contributor
      2. Filing Bug Reports
      3. Getting a MODx Account
      4. Using GitHub

Explanation of Directory Structure

Last edited by Mark Hamstra on Feb 9, 2018.

The root directory of MODX is split into several subdirectories, each with its own set of responsibilities and tasks. Some of these directories can be renamed and moved, and their locations can be configured during setup.


Connectors are essentially entry points for AJAX requests in MODX. They don't do any database manipulation on their own; they simply load up the main MODX class, sanitize any request data, and then handle the request by pointing to the appropriate Processor file.

For example, when we create a resource, we request connectors/resource/index.php?action=create. The index.php file will include the base connector file (connectors/index.php) which instantiates the main MODX object, handle any custom Context switching, and sanitize the GET or POST request. The connectors/resource/index.php will then "handle" the request and call the correct Processor file, which we will discuss later.

Notable Files

  • connectors/index.php- This file is particularly useful in creating your own connectors. Simply include this file in your connectors, and then handle the request using $modx->request->handleRequest();


The Core is what makes MODX, MODX. It is the base for all the libraries for Revolution. Most everything you need, with the exception of the manager files and the setup files, are in this directory.


The cache directory contains all of the cache files generated by MODX. Lexicons, elements, resources, RSS, and Smarty data are generated on-demand by MODX, meaning that they are only cached after being accessed for the first time.


All file logging in MODX is done here. You will find the error.log file here, which contains the date, time, file, and error which was logged by MODX.

To log an entry to this file, you can use the $modx->log() method.


This directory contains cache data for the mgr (Manager) context. Like every context cache, it will cache any context settings that have been overridden from their default System Settings.


A cache of every RSS feed in MODX.


Unlike the cache in MODX Evolution, the MODX Revolution cache is split up into several parts. Every context (ie. web and mgr) has a context.cache.php file. This file is like the config.cache.php file, except that it only caches settings that have been overridden from their default System Setting. Any context can override a system setting.

Additionally, the web context cache will contain separate directories for resources and elements. A resource with ID 12 will be found at cache/web/resources/12.cache.php. This new caching mechanism means that loading times will decrease, and the limit on the number of cacheable resources will disappear.


When you install a package using the Package Manager, a core/components/ / directory will be created to hold any files necessary for the installed component to run. Typically, any files needed to run in the Manager, such as controllers, model/schema data, processors and class files, should be stored here, as well as files you don't want web-accessible.


This directory contains the configuration file for MODX Revolution. It sets up database credentials and a number of MODX_ constants for the proper operation of your site.


This directory contains the changelog.txt file, the GPL license, and any tutorials that have been created for Revolution.


This contains default templating for error response messages in Revolution's front-end. You can customize those pages here.


After running the Export function in MODX Revolution, the exported HTML files for your site will be located here.


To run the Import function in MODX Revolution, you need to move your HTML files into this directory.


[Lexicons]in Revolution are different from language files in Evolution for two main reasons.

First, in Revolution, lexicon files are split up into separate directories, depending on their two-digit IANA code (for example, English lexicons are stored in /core/lexicon/en/). Inside these subdirectories are multiple files, in the format "topic.inc.php". A "topic" is simply a single lexicon file. Splitting lexicons into topics means that only the requiredlanguage strings are loaded, saving memory and loading time.

Second, all lexicons are stored in the MODX database, and later cached on-demand. This makes it possible to manage lexicons directly from the Manager, inside the [Lexicon Management]area.

To load a lexicon, one would use a format such as this:

    $modx->lexicon->load( 'lang:namespace:topic' );

# lang- the 2-digit IANA code. This is optional, and defaults to 'en'.

  1. namespace- Each lexicon has its own Namespace. The built-in namespace for MODX is "core". Package creators will also be able to create a custom namespace, and Manager users can also create their own namespaces as well.
  2. topic- The specific topic/file you want to load.


This is the model. What's a model, you say? Well, it's the M in MVC (model-view-controller), which is an OO paradigm that states that there should be at least three parts to an application. The Model, which contains the structure of the database and the hooks into it; the View, which is the GUI part of the application that contains no logic - just presentation; and the Controllers, which connect the model to the view.

So, MODX does model sort-of similar. We actually do a MVC/C model, in which we add a Connector access point and Processors to the model. We'll explain those as we come to them. What you need to know is that the model contains all the PHP classes that run Revolution, including the processors that handle specific functions - such as saving snippets, removing chunks, etc.


"Wait! I thought we were already in a modx dir? Why another modx subdirectory?" Good question. Well, MODX Revolution uses xPDO for its database management. xPDO uses the idea of 'packages' for different connections to different models. So, if I wanted to create my custom tables, I'd create a new xPDO package, and add it in at runtime. This way I could use the maps and classes created without having to modify the MODX core. This is shown in the Crea ting a 3rd Party Component tutorial.

So, that said, it can be inferred that the core/model/modx directory is referring to the "modx" package. Let's go inside it, and you'll see a ton of classes. These are the classes that are either xPDOObjects - which are PHP classes that represent tables in the DB (ie, modsnippet.class.php is a PHP class that is an object of modx_site_snippets), or they are functional classes, such as modcachemanager.class.php.

The subdirectories in this folder - not including mysql or processors - are subcategories of classes, that are loaded like: $modx->loadClass('transport.modPackageBuilder'); with the "." being the separation of directories.


This directory contains the class and map files for each xPDO object. Maps are simply PHP arrays containing the structure of the database table they reference.

Other database platforms such as pgsql, mssql, and others would also appear here.


This directory contains the individual processor files used in database manipulation. They are never accessed directly, and instead are accessed through connectors. This allows you to lock them down to prevent unauthorized access.


The schema is the XML representation of the MODX database. This is used in building new maps and classes, but is never actually read or parsed when MODX is running. For the most part, you can ignore this directory, as it is mainly used for development work. The tutorials on creating 3rd party components teach more about schemas.


This contains the Smarty libraries. It's simply an extraction of the Smarty files you can get from http://smarty.php.net. Nothing in this folder is customized for MODX - that happens elsewhere.

Smarty is an intelligent, object-oriented templating engine that uses dynamic, modifiable placeholders. Most pages seen in the Manager and during Setup are Smarty template (.tpl) files that MODX interacts with.

When you edit a resource (often a document) in the Manager, for example, you're looking at a page generated by the controller at manager/controllers/resource/staticresource/update.php. After setting the characteristics of the resource in the $resource array, this code renders the page:

    $modx->smarty->assign('resource',$resource); return $modx->smarty->fetch('resource/staticresource/update.tpl');

The Smarty placeholders in update.tpl are filled in with the data held in the $resource array.


Here you will find any transport packages you've downloaded via the Package Management section of Revolution, such as TinyMCE, Ditto, etc. The core package is also found here as well. This allows for easy installation and removal, as well as remote updating of installed packages.

When you build a package (for example, after checking out from SVN), the transport package will be stored here.


MODX Revolution was designed to use OpenExpedio (xPDO), an extension to PDO. It provides a uniform interface for manipulating databases, and makes it possible for MODX to support various database platforms besides MySQL.

This directory contains all of the class files needed by xPDO to do everything from query caching, to building transport packages and outputting data as a convenient JSON object.

These classes are used by MODX internally, and developers should never need to deal with them directly.

Notable Files

  • core/cache/config.cache.php- This is the cache file for all of the System Settings in MODX. Their database equivalents are found in the _system_settings table, and their xPDO equivalents are modSystemSetting objects.
    • Tip - If you ever get locked out by the CAPTCHA component, you can edit this file and set use_captchato '0' to disable CAPTCHA. Then you can log in and disable CAPTCHA in System Settings.
  • core/cache/sitePublishing.idx.php- In MODX Evolution, this file contained the cache data for all documents, chunks, and snippets. In Revolution, this is no longer the case, and this file now keeps track of cache refresh intervals.
  • core/cache/mgr/actions.cache.php- a map of all modAction objects.


The Manager is the MODX backend or administration area for creating resources, managing users, and performing overall site maintenance tasks.


This directory contains the ExtJS libraries, as well as the custom ModExt implementation. ModExt extends the original ExtJS library, to make development more convenient for users.


Controllers are the PHP files tied to modActions. They simply fetch data and return or output it to the browser for rendering and display. Whenever you load a page in the Manager, you are in effect telling MODX to load a particular Controller, which simply loads a Smarty template and outputs any necessary JavaScript to the browser.


This directory contains the template files for each manager page. They do not contain PHP code, but rather are used to organize HTML. If you are looking for the Smarty .tpl file for a particular manager page, check in the manager/templates/default/ directory.

Notable Files

  • manager/assets/ext2/ext-all.js- This is the main Ext library file, which must be included on all Manager pages (or any page using Ext). It's compressed to save space, decrease download time, and speed up page loads. However, if you're doing a lot of JavaScript work, you're bound to run into some cryptic errors because of the compression. The best way to deal with this is to simply rename this file, and then rename the ext-all.js file to ext-all-debug.js to use the uncompressed version during development. Just be sure to switch them back afterwards!


This directory is the equivalent of the "install" directory in MODX Evolution. It contains the necessary files needed to run Setup and perform a Fresh Installation or an Upgrade.


This directory is only present in version of MODX Revolution downloaded from the subversion server (as well as the "SDK" distribution). It contains the packaged MODX core data files necessary to install MODX to a database.

Notable Files

  • _build/transport.core.php- This file must be executed after downloading MODX Revolution, and prior to running Setup. After completion, you should notice a "core" directory inside your core/packages/ directory, which will contain all of the necessary [Vehicles]for installing MODX Revolution.


This directory is not present in MODX Revolution by default, but like in MODX Evolution, it is common to place images, CSS, JavaScript, and other media in here.


When you install a package using the Package Manager, an assets/components/ directory will be created to hold any necessary component files, such as JavaScript or images.

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