Default theme implementations

Functions and templates that present output to the user, and can be implemented by themes.

Drupal's presentation layer is a pluggable system known as the theme layer. Each theme can take control over most of Drupal's output, and has complete control over the CSS.

Inside Drupal, the theme layer is utilized by the use of the theme() function, which is passed the name of a component (the theme hook) and an array of variables. For example, theme('table', array('header' => $header, 'rows' => $rows)); Additionally, the theme() function can take an array of theme hooks, which can be used to provide 'fallback' implementations to allow for more specific control of output. For example, the function: theme(array('table__foo', 'table'), $variables) would look to see if 'table__foo' is registered anywhere; if it is not, it would 'fall back' to the generic 'table' implementation. This can be used to attach specific theme functions to named objects, allowing the themer more control over specific types of output.

As of Drupal 6, every theme hook is required to be registered by the module that owns it, so that Drupal can tell what to do with it and to make it simple for themes to identify and override the behavior for these calls.

The theme hooks are registered via hook_theme(), which returns an array of arrays with information about the hook. It describes the arguments the function or template will need, and provides defaults for the template in case they are not filled in. If the default implementation is a function, by convention it is named theme_HOOK().

Each module should provide a default implementation for theme_hooks that it registers. This implementation may be either a function or a template; if it is a function it must be specified via hook_theme(). By convention, default implementations of theme hooks are named theme_HOOK. Default template implementations are stored in the module directory.

Drupal's default template renderer is a simple PHP parsing engine that includes the template and stores the output. Drupal's theme engines can provide alternate template engines, such as XTemplate, Smarty and PHPTal. The most common template engine is PHPTemplate (included with Drupal and implemented in phptemplate.engine, which uses Drupal's default template renderer.

In order to create theme-specific implementations of these hooks, themes can implement their own version of theme hooks, either as functions or templates. These implementations will be used instead of the default implementation. If using a pure .theme without an engine, the .theme is required to implement its own version of hook_theme() to tell Drupal what it is implementing; themes utilizing an engine will have their well-named theming functions automatically registered for them. While this can vary based upon the theme engine, the standard set by phptemplate is that theme functions should be named THEMENAME_HOOK. For example, for Drupal's default theme (Garland) to implement the 'table' hook, the phptemplate.engine would find garland_table().

The theme system is described and defined in theme.inc.

See also

theme()

@see hook_theme()

End of "defgroup themeable".

Functions

Name	Location	Description
template_preprocess_menu_tree	includes/menu.inc	Preprocess the rendered tree for theme_menu_tree.
template_preprocess_username	includes/theme.inc	Preprocess variables for theme_username().
template_process_username	includes/theme.inc	Process variables for theme_username().
theme_admin_block	modules/system/system.admin.inc	This function formats an administrative block for display.
theme_admin_block_content	modules/system/system.admin.inc	This function formats the content of an administrative block.
theme_admin_page	modules/system/system.admin.inc	This function formats an administrative page for viewing.
theme_aggregator_page_opml	modules/aggregator/aggregator.pages.inc	Theme the OPML feed output.
theme_aggregator_page_rss	modules/aggregator/aggregator.pages.inc	Theme the RSS output.
theme_book_admin_table	modules/book/book.admin.inc	Theme function for the book administration page form.
theme_book_title_link	modules/book/book.module	Generate the HTML output for a link to a book title when used as a block title.
theme_breadcrumb	includes/theme.inc	Return a themed breadcrumb trail.
theme_button	includes/form.inc	Theme a button form element.
theme_checkbox	includes/form.inc	Theme a checkbox form element.
theme_checkboxes	includes/form.inc	Theme a set of checkbox form elements.
theme_color_scheme_form	modules/color/color.module	Theme the color form.
theme_comment_post_forbidden	modules/comment/comment.module	Theme a "you can't post comments" notice.
theme_confirm_form	modules/system/system.module	Theme confirmation forms.
theme_container	includes/form.inc	Adds a container for grouped items.
theme_dashboard	modules/dashboard/dashboard.module	Theme the entire dashboard.
theme_dashboard_admin	modules/dashboard/dashboard.module	Theme the page containing the dashboard.
theme_dashboard_disabled_block	modules/dashboard/dashboard.module	Theme a disabled block, for display in dashboard customization mode.
theme_dashboard_disabled_blocks	modules/dashboard/dashboard.module	Theme a set of disabled blocks, for display in dashboard customization mode.
theme_dashboard_region	modules/dashboard/dashboard.module	Theme a generic dashboard region.
theme_date	includes/form.inc	Theme a date selection form element.
theme_feed_icon	includes/theme.inc	Return code that emits an feed icon.
theme_field	modules/field/field.module	Returns a themed field.
theme_fieldset	includes/form.inc	Theme a fieldset form element.
theme_file	includes/form.inc	Theme a file upload form element.
theme_filter_admin_format_filter_order	modules/filter/filter.admin.inc	Theme text format filter order form elements as tabledrag.
theme_filter_admin_overview	modules/filter/filter.admin.inc	Theme the text format administration overview form.
theme_filter_guidelines	modules/filter/filter.module	Format guidelines for a text format.
theme_filter_tips	modules/filter/filter.pages.inc	Render HTML for a set of filter tips.
theme_filter_tips_more_info	modules/filter/filter.module	Format a link to the more extensive filter tips.
theme_form	includes/form.inc	Theme a form.
theme_form_element	includes/form.inc	Theme a form element.
theme_form_element_label	includes/form.inc	Theme a form element label and required marker.
theme_form_required_marker	includes/form.inc	Theme the marker for required form elements.
theme_forum_form	modules/forum/forum.admin.inc	Theme forum forms.
theme_hidden	includes/form.inc	Theme a hidden form element.
theme_html_tag	includes/theme.inc	Generate the output for a generic HTML tag with attributes.
theme_image	includes/theme.inc	Return a themed image.
theme_image_anchor	modules/image/image.admin.inc	Theme callback for displaying a grid of checkboxes.
theme_image_crop_summary	modules/image/image.admin.inc	Theme callback for image crop effect summary output.
theme_image_resize_summary	modules/image/image.admin.inc	Theme callback for image resize effect summary output.
theme_image_rotate_summary	modules/image/image.admin.inc	Theme callback for image rotate effect summary output.
theme_image_scale_summary	modules/image/image.admin.inc	Theme callback for image scale effect summary output.
theme_image_style_effects	modules/image/image.admin.inc	Theme callback for listing the effects within a specific image style.
theme_image_style_list	modules/image/image.admin.inc	Display the page containing the list of image styles.
theme_image_style_preview	modules/image/image.admin.inc	Theme callback for displaying a preview of an image style.
theme_indentation	includes/theme.inc	Create a standard indentation div. Used for drag and drop tables.
theme_item_list	includes/theme.inc	Return a themed list of items.
theme_link	includes/theme.inc	Return a themed link.
theme_links	includes/theme.inc	Return a themed set of links.
theme_locale_date_format_form	modules/locale/locale.admin.inc	Theme locale date format form.
theme_locale_languages_configure_form	modules/locale/locale.admin.inc	Theme the language configure form.
theme_locale_languages_overview_form	modules/locale/locale.admin.inc	Theme the language overview form.
theme_mark	includes/theme.inc	Return a themed marker, useful for marking new or updated content.
theme_menu_link	includes/menu.inc	Generate the HTML output for a menu link and submenu.
theme_menu_local_action	includes/menu.inc	Generate the HTML output for a single local action link.
theme_menu_local_task	includes/menu.inc	Generate the HTML output for a single local task link.
theme_menu_local_tasks	includes/menu.inc	Returns renderable local tasks.
theme_menu_overview_form	modules/menu/menu.admin.inc	Theme the menu overview form into a table.
theme_menu_tree	includes/menu.inc	Theme wrapper for the HTML output for a menu sub-tree.
theme_more_help_link	includes/theme.inc	Returns code that emits the 'more help'-link.
theme_more_link	includes/theme.inc	Returns code that emits the 'more' link used on blocks.
theme_node_add_list	modules/node/node.pages.inc	Display the list of available node types for node creation.
theme_node_filters	modules/node/node.admin.inc	Theme node administration filter selector.
theme_node_list	modules/node/node.module	Format a listing of links to nodes.
theme_node_log_message	modules/node/node.module	Theme a log message.
theme_node_preview	modules/node/node.pages.inc	Display a node preview for display during node creation and editing.
theme_node_search_admin	modules/node/node.module	Theme the content ranking part of the search settings admin page.
theme_pager	includes/pager.inc	Format a query pager.
theme_pager_first	includes/pager.inc	Format a "first page" link.
theme_pager_last	includes/pager.inc	Format a "last page" link.
theme_pager_link	includes/pager.inc	Format a link to a specific query result page.
theme_pager_next	includes/pager.inc	Format a "next page" link.
theme_pager_previous	includes/pager.inc	Format a "previous page" link.
theme_password	includes/form.inc	Theme a password form element.
theme_poll_choices	modules/poll/poll.module	Theme the admin poll form for choices.
theme_profile_admin_overview	modules/profile/profile.admin.inc	Theme the profile field overview into a drag and drop enabled table.
theme_progress_bar	includes/theme.inc	Return a themed progress bar.
theme_radio	includes/form.inc	Theme a radio button form element.
theme_radios	includes/form.inc	Theme a set of radio button form elements.
theme_rdf_metadata	modules/rdf/rdf.module	Outputs a series of empty spans for exporting RDF metadata in RDFa.
theme_rdf_template_variable_wrapper	modules/rdf/rdf.module	Wraps a template variable in an HTML element with the desired attributes.
theme_select	includes/form.inc	Theme select form element.
theme_shortcut_set_customize	modules/shortcut/shortcut.admin.inc	Themes the shortcut set customization form.
theme_status_messages	includes/theme.inc	Return a themed set of status and/or error messages. The messages are grouped by type.
theme_status_report	modules/system/system.admin.inc	Theme requirements status report.
theme_submit	includes/form.inc	Theme a submit button form element.
theme_syslog_format	modules/syslog/syslog.module	Format a system log entry.
theme_system_admin_by_module	modules/system/system.admin.inc	Theme output of the dashboard page.
theme_system_compact_link	modules/system/system.module	Display the link to show or hide inline help descriptions.
theme_system_date_time_settings	modules/system/system.admin.inc	Theme function for date settings form.
theme_system_modules_fieldset	modules/system/system.admin.inc	Theme callback for the modules form.
theme_system_modules_incompatible	modules/system/system.admin.inc	Themes an incompatible message.
theme_system_modules_uninstall	modules/system/system.admin.inc	Themes a table of currently disabled modules.
theme_system_powered_by	modules/system/system.module	Format the Powered by Drupal text.
theme_system_settings_form	modules/system/system.module	Theme function for the system settings form.
theme_system_themes_page	modules/system/system.admin.inc	Theme function for the system themes form.
theme_table	includes/theme.inc	Return a themed table.
theme_tableselect	includes/form.inc	Formats a table with radio buttons or checkboxes.
theme_tablesort_indicator	includes/theme.inc	Return a themed sort icon.
theme_table_select_header_cell	includes/theme.inc	Returns a header cell for tables that have a select all functionality.
theme_task_list	includes/theme.maintenance.inc	Return a themed list of maintenance tasks to perform.
theme_taxonomy_overview_terms	modules/taxonomy/taxonomy.admin.inc	Theme the terms overview as a sortable list of terms.
theme_taxonomy_overview_vocabularies	modules/taxonomy/taxonomy.admin.inc	Theme the vocabulary overview as a sortable list of vocabularies.
theme_textarea	includes/form.inc	Theme a textarea form element.
theme_textfield	includes/form.inc	Theme a textfield form element.
theme_text_format_wrapper	modules/filter/filter.module	Render a text format-enabled form element.
theme_trigger_display	modules/trigger/trigger.admin.inc	Displays actions assigned to this hook in a table.
theme_update_last_check	modules/update/update.module	Render the HTML to display the last time we checked for update data.
theme_update_manager_update_form	modules/update/update.manager.inc	Theme the first page in the update manager wizard to select projects.
theme_update_report	modules/update/update.report.inc	Theme project status report.
theme_update_version	modules/update/update.report.inc	Theme the version display of a project.
theme_username	includes/theme.inc	Format a username.
theme_user_admin_new_role	modules/user/user.admin.inc	Theme the new-role form.
theme_user_admin_permissions	modules/user/user.admin.inc	Theme the administer permissions page.
theme_user_filters	modules/user/user.admin.inc	Theme user administration filter selector.
theme_user_list	modules/user/user.module	Make a list of users.
theme_user_signature	modules/user/user.module	Theme output of user signature.
theme_vertical_tabs	includes/form.inc	Makes the element's children fieldsets be vertical tabs.