Code Reference Map

Key Files & Classes

Location	Role
`ui_icons.info.yml`	Module metadata
`ui_icons.services.yml`	Services (`ui_icons.search`, `ui_icons.twig_extension`)
`ui_icons.install`	`ui_icons_update_11201()` — clears the removed backport/iconify modules
`src/Hook/UiIconsHooks.php`	hook_help, hook_theme, hook_preprocess_icon_selector; `THEME_LIBRARIES` maps admin theme → picker CSS library
`src/IconSearch.php`	Fuzzy search across packs (cached)
`src/Template/IconPreviewTwigExtension.php`	The `icon_preview()` Twig function
`src/Element/IconAutocomplete.php`	The `icon_autocomplete` form element
`src/Controller/IconAutocompleteController.php`	Backend for autocomplete suggestions
`templates/icon-selector.html.twig`	Autocomplete UI
`templates/icon-preview.html.twig`	Per-icon preview
`modules/ui_icons_field/src/Plugin/Field/FieldType/IconType.php`	`ui_icon` field type — `target_id` schema, `ICON_ID_PCRE`
`modules/ui_icons_field/src/Hook/UiIconsFieldHooks.php`	hook_config_schema_info_alter
`modules/ui_icons_ckeditor5/`	CKEditor 5 plugin + dialog; `js/ckeditor5_plugins/icon/src/iconToolbar.js` is the in-place Edit balloon
`modules/ui_icons_text/src/Plugin/Filter/IconEmbed.php`	The `icon_embed` text filter
`modules/ui_icons_text/src/Hook/UiIconsTextHooks.php`	Filter-format validation: allowed HTML, filter order, `filter_html_escape`
`modules/ui_icons_picker/src/Element/IconPicker.php`	Modal picker form element
`modules/ui_icons_patterns/src/Plugin/UiPatterns/PropType/IconPropType.php`	Icon PropType for UI Patterns
`modules/ui_icons_menu/src/Hook/UiIconsMenuHooks.php`	Menu base-field alter + the three hooks that render icons into link titles
`modules/ui_icons_media/`	Media source plugin
`modules/ui_icons_canvas/src/Hook/UiIconsCanvasHooks.php`	Canvas widget transform + `x-canvas-prop: ui-icon` shape routing
`modules/ui_icons_library/src/Controller/LibraryIndex.php`	Admin browser
`modules/ui_icons_library/src/Hook/UiIconsLibraryHooks.php`	hook_theme
`modules/ui_icons_font/src/Plugin/IconExtractor/FontExtractor.php`	Font extractor
`modules/ui_icons_font/src/Hook/UiIconsFontRequirements.php`	Status-report check for `dompdf/php-font-lib`

The project ships no .module files as of 2.0.0 — every hook is an attributed method on a src/Hook/ class.

The file paths in the table above are 2.0.0 paths and are unverified. On 1.1.2 the layout is the pre-OO one: there is no src/Hook/ directory anywhere in the project, no ui_icons.install, and the hooks live in procedural .module files — ui_icons.module (ui_icons_help(), ui_icons_theme(), template_preprocess_icon_selector()) and ui_icons_menu.module (ui_icons_menu_entity_base_field_info_alter(), ui_icons_menu_preprocess_menu(), ui_icons_menu_link_alter(), ui_icons_menu_navigation_menu_link_tree_alter()). Note that the hook set is verified — those four menu hooks and their behaviour are exactly what Menu Integration describes — it is only the class paths that are unread. THEME_LIBRARIES likewise does not exist on 1.1.2, where the same job is done by a private _ui_icons_is_theme_active() helper that special-cases gin, ui_suite_daisyui and ui_suite_dsfr (and nothing for Claro). ui_icons.services.yml and its two services (ui_icons.search, ui_icons.twig_extension) are verified on 1.1.2 and unchanged.

Drupal Core Icon API (the engine)

\Drupal\Core\Theme\Icon\IconDefinition
\Drupal\Core\Theme\Icon\IconDefinitionInterface
\Drupal\Core\Theme\Icon\IconExtractorBase
\Drupal\Core\Theme\Icon\IconPackManagerInterface
#[\Drupal\Core\Theme\Icon\Attribute\IconExtractor]
Service: plugin.manager.icon_pack

Hooks Used

All are #[Hook]-attributed methods on 2.0.0 (unverified — see caveat above); on 1.1.2 the same hook set is procedural functions in .module files.

hook_help — admin help
hook_theme — register icon-selector and icon-preview templates (also in ui_icons_library)
hook_preprocess_icon_selector — attach theme-specific picker libraries (default admin/Claro, gin, daisyui, dsfr)
hook_entity_base_field_info_alter (ui_icons_menu) — add icon to menu_link_content
hook_preprocess_menu, hook_navigation_menu_link_tree_alter, hook_link_alter (ui_icons_menu) — render the icon into link titles
hook_form_filter_format_add_form_alter / hook_form_filter_format_edit_form_alter (ui_icons_text) — attach the filter-order and allowed-HTML validation
hook_config_schema_info_alter (ui_icons_field)
hook_runtime_requirements (ui_icons_font) — the font-library status check
hook_field_widget_info_alter, hook_canvas_storable_prop_shape_alter (ui_icons_canvas)

Form Element Types

icon_autocomplete — text + autocomplete dropdown
icon_picker — modal grid picker (extends autocomplete)

Cache

Cache tags: icon_pack_plugin, icon_pack_collector. Clear with drush cr or by invalidating these tags.

Common Mistakes

Wrong: looking for src/Hook/UiIconsHooks.php (or any src/Hook/ class) on a 1.1.2 site → Right: that layout is 2.0.0-only and unverified; on 1.1.2 the same logic lives in ui_icons.module and ui_icons_menu.module
Wrong: assuming ui_icons.install exists on every version → Right: 1.1.2 ships no install file at all; ui_icons_update_11201() can only run on 2.0.0