Angular Material Developer

Angular Material Developer Guidelines

Pairs with angular-developer , that skill provides Angular fundamentals (signals, DI, routing, forms, SSR, accessibility). This skill focuses on Angular Material specifics. Install both for the best experience.

Compatibility

• Tracks: @angular/material@22.1.1 (Angular v22), paired with @angular/cdk@22.1.1 (Material peers an exact cdk version, keep the two pinned together). The v21-aligned line remains at 21.2.x for legacy projects.
• Animations peer dropped (v21.2+): Material no longer declares an @angular/animations peer dependency and animates via native CSS. ng add @angular/material on 21.2+/22 does not wire provideAnimationsAsync() and does not require @angular/animations, do not add either to a fresh Material 22 app. (Earlier v21.x and all v18-20 apps still need the provider; see setup.md.)
• Works for: Material v19 → v22 projects (M3 theming system landed in v19; older majors used M2 with the now-legacy mat.define-light-theme / mat.define-dark-theme API).
• Angular: v19 or newer required. v22 requires Node 22 or 26 and TypeScript 6. The skill assumes standalone components, control flow (@if / @for), and signal-based APIs.
• Sass: required for theming. The build pipeline must support .scss (Angular CLI does by default). Standalone CSS-only theming is not supported by Material's theming engine.
• Not supported: Material v18 and below (M2-only with mat.define-*-theme() API), Angular v18 or below (NgModule patterns + older animations API).

v22 breaking changes (from v21)

The v21 → v22 jump has real API drift, not just an Angular version bump. Watch for:

• Combobox: legacy combobox and autocomplete promoted / removed. SimpleCombobox promoted to Combobox with all simpleCombobox* symbols renamed to combobox*.
• List: MatListOption.checkboxPosition removed, use togglePosition instead. MatListOptionCheckboxPosition renamed to MatListOptionTogglePosition.
• CDK: injector parameter is now required on ConfigurableFocusTrap and FocusTrap constructors. ConfigurableFocusTrapFactory.create boolean parameter replaced with a config object. DropListRef.drop event parameter is now required. ContextMenuTracker renamed to MenuTracker. Removed: CDK_DESCRIBEDBY_HOST_ATTRIBUTE, CDK_DESCRIBEDBY_ID_PREFIX, MESSAGES_CONTAINER_ID.
• Multiple components: input/model rename from values to value across Combobox, Listbox, Tree, Menu, Toolbar, Select. Constructors with rest arguments removed (affects code that extends Material or CDK components).
• Dialog / Overlay: ArrowViewState and ArrowViewStateTransition types removed.

Most of these have automatic ng update migrations. When in doubt, run ng update @angular/material and let the schematic do the work before hand-editing.

v22 new features worth knowing

• Signal Forms stable (was experimental in v21). Angular's signal-based form API is now safe to use in production. mat-form-field composes with both ReactiveFormsModule and Signal Forms.
• Angular Aria stable (was preview). New accessibility primitives ship in the framework, which reduces the need to reach for CDK's a11y module for some patterns.
• Button progress indicator support inside <button> component.
• Portal directives support on ComponentPortal.
• Separate tab animation durations (per-tab enter/exit timing).

1. Check the project's Material version before answering. Material's M3 theming engine was introduced in v19 (mat.theme() mixin replacing mat.define-light-theme and mat.define-dark-theme). Code generated against M3 will silently break on M2 projects. package.json is the source of truth.

2. Detect the theming generation in styles.scss:

   • If you see @include mat.theme((...)) → M3 (v19+, default). Use mat.theme(), Material's prebuilt palettes, and CSS variable overrides.
   • If you see mat.define-light-theme(...) or mat.define-dark-theme(...) plus @include mat.all-component-themes($theme) → M2 (legacy). Recommend migrating, see migration.md.
   • The two systems compile and behave very differently. See theming.md.

3. Components are standalone since v15. Always import the standalone class (e.g. MatButton from '@angular/material/button'), not the legacy MatButtonModule. The modules still re-export everything for backwards compatibility but should not be added to new code.

4. After generating Material code, run ng build. The most common AI mistakes are: (a) using v17-era mat.define-light-theme syntax in a v19+ project (compiles but silently emits no CSS vars); (b) forgetting provideAnimationsAsync(), which makes ripples, menu open/close, and dialog backdrop animations no-op; (c) missing @angular/cdk peer dep, Material imports cascade through it; (d) using MatTable without a MatSort / MatPaginator wiring up, the column header sort UI appears but does nothing.

Material architecture: components, CDK, theming

Angular Material ships three layers:

• Components (@angular/material/*) , the styled mat-* components themselves: MatButton, MatFormField, MatTable, MatDialog, etc. Each lives at its own import path.
• CDK (@angular/cdk/*) , unstyled primitives Material composes on top of: Overlay, Portal, A11y (FocusTrap, LiveAnnouncer, ListKeyManager), DragDrop, VirtualScroll, Stepper. Always installed as a peer dep alongside Material. Useful on its own when you need a primitive but don't want Material's styling. See cdk.md.
• Theming engine (@angular/material/_index.scss) , the Sass mixins (mat.theme(), mat.theme-overrides()) that emit CSS variables consumed by every component. Sass is required, no CSS-only theming path.

Default to importing from @angular/material/<component> (e.g. MatButton from '@angular/material/button'). Reach for @angular/cdk/<primitive> only when you need the headless primitive or are building a custom-styled component composing Material's behaviour.

Installation and theming

• Setup: ng add @angular/material (handles the install + writes a default theme; on v18-v21.1 it also wires provideAnimationsAsync(), on 21.2+/22 it does not, Material animates via native CSS), or manual install. Read setup.md
• Theming (M3): mat.theme() mixin, prebuilt palettes (mat.$violet-palette, mat.$azure-palette, etc.), density and typography knobs, light dark color-scheme, per-component overrides via mat.<component>-overrides(). Read theming.md
• M2 → M3 migration: the v19 ng-update schematic + manual fix patterns. Read migration.md

Components

Angular Material documents 40+ components grouped by category. Each category file below covers the components, their key inputs, common patterns, and gotchas.

• Form Controls: Autocomplete, Checkbox, Datepicker, FormField, Input, Radio, Select, Slider, SlideToggle. Read form-controls.md
• Buttons & Indicators: Button, ButtonToggle, Badge, Chip, Icon, ProgressBar, ProgressSpinner, Ripple. Read buttons-indicators.md
• Layout: Card, Divider, ExpansionPanel, GridList, List, Stepper, Tabs, Tree. Read layout.md
• Navigation: Menu, Sidenav, Toolbar. Read navigation.md
• Popups & Modals: BottomSheet, Dialog, Snackbar, Tooltip. Read overlays.md
• Data Table: Table, Paginator, Sort, MatTableDataSource. Read data-table.md

CDK primitives

• CDK: Overlay, Portal, A11y (FocusTrap, FocusMonitor, LiveAnnouncer, ListKeyManager), Drag-Drop, VirtualScroll, Stepper, ScrollDispatcher, Layout (Breakpoints). Read cdk.md

Forms integration

• Forms: Wiring Material components to ReactiveForms (the canonical path) and Signal Forms (Angular v22+) via mat-form-field, MatInput / MatSelect / MatDatepicker, ErrorStateMatcher patterns, <mat-error> display, and ControlValueAccessor for custom controls. Read forms.md

Accessibility

• Accessibility: Material's WCAG 2.1 AA targets, FocusMonitor for keyboard-vs-mouse focus styling, LiveAnnouncer for transient announcements, RTL support, the things Material gives you free and the things you still need to do. Read accessibility.md