refactor(material/datepicker): convert internal calendar state to signals

Converts some of the internal calendar state to signals to test the waters on how breaking it would be.

Author: crisbeto

goldens/material/datepicker/index.api.md

@@ -667,8 +667,8 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
     // (undocumented)
     readonly _changeDetectorRef: ChangeDetectorRef;
     comparisonEnd: D | null;
-    _comparisonRangeEnd: number | null;
-    _comparisonRangeStart: number | null;
+    _comparisonRangeEnd: i0.WritableSignal<number | null>;
+    _comparisonRangeStart: i0.WritableSignal<number | null>;
     comparisonStart: D | null;
     // (undocumented)
     _dateAdapter: DateAdapter<D, any>;
@@ -679,43 +679,43 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
     protected _dragEnded(event: MatCalendarUserEvent<D | null>): void;
     readonly dragStarted: EventEmitter<MatCalendarUserEvent<D>>;
     endDateAccessibleName: string | null;
-    _firstWeekOffset: number;
+    _firstWeekOffset: i0.WritableSignal<number>;
     _focusActiveCell(movePreview?: boolean): void;
     _focusActiveCellAfterViewChecked(): void;
     _handleCalendarBodyKeydown(event: KeyboardEvent): void;
     _handleCalendarBodyKeyup(event: KeyboardEvent): void;
     _init(): void;
-    _isRange: boolean;
+    _isRange: i0.WritableSignal<boolean>;
     _matCalendarBody: MatCalendarBody;
     get maxDate(): D | null;
     set maxDate(value: D | null);
     get minDate(): D | null;
     set minDate(value: D | null);
-    _monthLabel: string;
+    _monthLabel: i0.WritableSignal<string>;
     // (undocumented)
     ngAfterContentInit(): void;
     // (undocumented)
     ngOnChanges(changes: SimpleChanges): void;
     // (undocumented)
     ngOnDestroy(): void;
     _previewChanged({ event, value: cell }: MatCalendarUserEvent<MatCalendarCell<D> | null>): void;
-    _previewEnd: number | null;
-    _previewStart: number | null;
-    _rangeEnd: number | null;
-    _rangeStart: number | null;
+    _previewEnd: i0.WritableSignal<number | null>;
+    _previewStart: i0.WritableSignal<number | null>;
+    _rangeEnd: i0.WritableSignal<number | null>;
+    _rangeStart: i0.WritableSignal<number | null>;
     get selected(): DateRange<D> | D | null;
     set selected(value: DateRange<D> | D | null);
     readonly selectedChange: EventEmitter<D | null>;
     startDateAccessibleName: string | null;
-    _todayDate: number | null;
+    _todayDate: i0.WritableSignal<number | null>;
     _updateActiveDate(event: MatCalendarUserEvent<number>): void;
     readonly _userSelection: EventEmitter<MatCalendarUserEvent<D | null>>;
-    _weekdays: {
+    _weekdays: i0.WritableSignal<{
         long: string;
         narrow: string;
         id: number;
-    }[];
-    _weeks: MatCalendarCell[][];
+    }[]>;
+    _weeks: i0.WritableSignal<MatCalendarCell<any>[][]>;
     // (undocumented)
     static ɵcmp: i0.ɵɵComponentDeclaration<MatMonthView<any>, "mat-month-view", ["matMonthView"], { "activeDate": { "alias": "activeDate"; "required": false; }; "selected": { "alias": "selected"; "required": false; }; "minDate": { "alias": "minDate"; "required": false; }; "maxDate": { "alias": "maxDate"; "required": false; }; "dateFilter": { "alias": "dateFilter"; "required": false; }; "dateClass": { "alias": "dateClass"; "required": false; }; "comparisonStart": { "alias": "comparisonStart"; "required": false; }; "comparisonEnd": { "alias": "comparisonEnd"; "required": false; }; "startDateAccessibleName": { "alias": "startDateAccessibleName"; "required": false; }; "endDateAccessibleName": { "alias": "endDateAccessibleName"; "required": false; }; "activeDrag": { "alias": "activeDrag"; "required": false; }; }, { "selectedChange": "selectedChange"; "_userSelection": "_userSelection"; "dragStarted": "dragStarted"; "dragEnded": "dragEnded"; "activeDateChange": "activeDateChange"; }, never, never, true, never>;
     // (undocumented)
@@ -751,10 +751,10 @@ export class MatMultiYearView<D> implements AfterContentInit, OnDestroy {
     get selected(): DateRange<D> | D | null;
     set selected(value: DateRange<D> | D | null);
     readonly selectedChange: EventEmitter<D>;
-    _selectedYear: number | null;
-    _todayYear: number;
+    _selectedYear: i0.WritableSignal<number | null>;
+    _todayYear: i0.WritableSignal<number>;
     _updateActiveDate(event: MatCalendarUserEvent<number>): void;
-    _years: MatCalendarCell[][];
+    _years: i0.WritableSignal<MatCalendarCell<any>[][]>;
     readonly yearSelected: EventEmitter<D>;
     _yearSelected(event: MatCalendarUserEvent<number>): void;
     // (undocumented)
@@ -831,7 +831,7 @@ export class MatYearView<D> implements AfterContentInit, OnDestroy {
     set maxDate(value: D | null);
     get minDate(): D | null;
     set minDate(value: D | null);
-    _months: MatCalendarCell[][];
+    _months: i0.WritableSignal<MatCalendarCell<any>[][]>;
     readonly monthSelected: EventEmitter<D>;
     _monthSelected(event: MatCalendarUserEvent<number>): void;
     // (undocumented)
@@ -841,10 +841,10 @@ export class MatYearView<D> implements AfterContentInit, OnDestroy {
     get selected(): DateRange<D> | D | null;
     set selected(value: DateRange<D> | D | null);
     readonly selectedChange: EventEmitter<D>;
-    _selectedMonth: number | null;
-    _todayMonth: number | null;
+    _selectedMonth: i0.WritableSignal<number | null>;
+    _todayMonth: i0.WritableSignal<number | null>;
     _updateActiveDate(event: MatCalendarUserEvent<number>): void;
-    _yearLabel: string;
+    _yearLabel: i0.WritableSignal<string>;
     // (undocumented)
     static ɵcmp: i0.ɵɵComponentDeclaration<MatYearView<any>, "mat-year-view", ["matYearView"], { "activeDate": { "alias": "activeDate"; "required": false; }; "selected": { "alias": "selected"; "required": false; }; "minDate": { "alias": "minDate"; "required": false; }; "maxDate": { "alias": "maxDate"; "required": false; }; "dateFilter": { "alias": "dateFilter"; "required": false; }; "dateClass": { "alias": "dateClass"; "required": false; }; }, { "selectedChange": "selectedChange"; "monthSelected": "monthSelected"; "activeDateChange": "activeDateChange"; }, never, never, true, never>;
     // (undocumented)

src/material/datepicker/month-view.html

@@ -1,7 +1,7 @@
 <table class="mat-calendar-table" role="grid">
   <thead class="mat-calendar-table-header">
     <tr>
-      @for (day of _weekdays; track day.id) {
+      @for (day of _weekdays(); track day.id) {
         <th scope="col">
           <span class="cdk-visually-hidden">{{day.long}}</span>
           <span aria-hidden="true">{{day.narrow}}</span>
@@ -11,16 +11,16 @@
     <tr aria-hidden="true"><th class="mat-calendar-table-header-divider" colspan="7"></th></tr>
   </thead>
   <tbody mat-calendar-body
-         [label]="_monthLabel"
-         [rows]="_weeks"
-         [todayValue]="_todayDate!"
-         [startValue]="_rangeStart!"
-         [endValue]="_rangeEnd!"
-         [comparisonStart]="_comparisonRangeStart"
-         [comparisonEnd]="_comparisonRangeEnd"
-         [previewStart]="_previewStart"
-         [previewEnd]="_previewEnd"
-         [isRange]="_isRange"
+         [label]="_monthLabel()"
+         [rows]="_weeks()"
+         [todayValue]="_todayDate()!"
+         [startValue]="_rangeStart()!"
+         [endValue]="_rangeEnd()!"
+         [comparisonStart]="_comparisonRangeStart()"
+         [comparisonEnd]="_comparisonRangeEnd()"
+         [previewStart]="_previewStart()"
+         [previewEnd]="_previewEnd()"
+         [isRange]="_isRange()"
          [labelMinRequiredCells]="3"
          [activeCell]="_dateAdapter.getDate(activeDate) - 1"
          [startDateAccessibleName]="startDateAccessibleName"

src/material/datepicker/month-view.ts

@@ -34,6 +34,7 @@ import {
   SimpleChanges,
   OnChanges,
   inject,
+  signal,
 } from '@angular/core';
 import {DateAdapter, MAT_DATE_FORMATS, MatDateFormats} from '../core';
 import {Directionality} from '@angular/cdk/bidi';
@@ -183,40 +184,40 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
   @ViewChild(MatCalendarBody) _matCalendarBody: MatCalendarBody;
 
   /** The label for this month (e.g. "January 2017"). */
-  _monthLabel: string;
+  _monthLabel = signal('');
 
   /** Grid of calendar cells representing the dates of the month. */
-  _weeks: MatCalendarCell[][];
+  _weeks = signal<MatCalendarCell[][]>([]);
 
   /** The number of blank cells in the first row before the 1st of the month. */
-  _firstWeekOffset: number;
+  _firstWeekOffset = signal(0);
 
   /** Start value of the currently-shown date range. */
-  _rangeStart: number | null;
+  _rangeStart = signal<number | null>(null);
 
   /** End value of the currently-shown date range. */
-  _rangeEnd: number | null;
+  _rangeEnd = signal<number | null>(null);
 
   /** Start value of the currently-shown comparison date range. */
-  _comparisonRangeStart: number | null;
+  _comparisonRangeStart = signal<number | null>(null);
 
   /** End value of the currently-shown comparison date range. */
-  _comparisonRangeEnd: number | null;
+  _comparisonRangeEnd = signal<number | null>(null);
 
   /** Start of the preview range. */
-  _previewStart: number | null;
+  _previewStart = signal<number | null>(null);
 
   /** End of the preview range. */
-  _previewEnd: number | null;
+  _previewEnd = signal<number | null>(null);
 
   /** Whether the user is currently selecting a range of dates. */
-  _isRange: boolean;
+  _isRange = signal(false);
 
   /** The date of the month that today falls on. Null if today is in another month. */
-  _todayDate: number | null;
+  _todayDate = signal<number | null>(null);
 
   /** The names of the weekdays. */
-  _weekdays: {long: string; narrow: string; id: number}[];
+  _weekdays = signal<{long: string; narrow: string; id: number}[]>([]);
 
   constructor(...args: unknown[]);
 
@@ -359,7 +360,7 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
         return;
       case ESCAPE:
         // Abort the current range selection if the user presses escape mid-selection.
-        if (this._previewEnd != null && !hasModifierKey(event)) {
+        if (this._previewEnd() != null && !hasModifierKey(event)) {
           this._clearPreview();
           // If a drag is in progress, cancel the drag without changing the
           // current selection.
@@ -402,23 +403,26 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
   /** Initializes this month view. */
   _init() {
     this._setRanges(this.selected);
-    this._todayDate = this._getCellCompareValue(this._dateAdapter.today());
-    this._monthLabel = this._dateFormats.display.monthLabel
-      ? this._dateAdapter.format(this.activeDate, this._dateFormats.display.monthLabel)
-      : this._dateAdapter
-          .getMonthNames('short')
-          [this._dateAdapter.getMonth(this.activeDate)].toLocaleUpperCase();
+    this._todayDate.set(this._getCellCompareValue(this._dateAdapter.today()));
+    this._monthLabel.set(
+      this._dateFormats.display.monthLabel
+        ? this._dateAdapter.format(this.activeDate, this._dateFormats.display.monthLabel)
+        : this._dateAdapter
+            .getMonthNames('short')
+            [this._dateAdapter.getMonth(this.activeDate)].toLocaleUpperCase(),
+    );
 
     let firstOfMonth = this._dateAdapter.createDate(
       this._dateAdapter.getYear(this.activeDate),
       this._dateAdapter.getMonth(this.activeDate),
       1,
     );
-    this._firstWeekOffset =
+    this._firstWeekOffset.set(
       (DAYS_PER_WEEK +
         this._dateAdapter.getDayOfWeek(firstOfMonth) -
         this._dateAdapter.getFirstDayOfWeek()) %
-      DAYS_PER_WEEK;
+        DAYS_PER_WEEK,
+    );
 
     this._initWeekdays();
     this._createWeekCells();
@@ -446,8 +450,8 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
         this.selected as DateRange<D>,
         event,
       );
-      this._previewStart = this._getCellCompareValue(previewRange.start);
-      this._previewEnd = this._getCellCompareValue(previewRange.end);
+      this._previewStart.set(this._getCellCompareValue(previewRange.start));
+      this._previewEnd.set(this._getCellCompareValue(previewRange.end));
 
       if (this.activeDrag && value) {
         const dragRange = this._rangeStrategy.createDrag?.(
@@ -458,8 +462,8 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
         );
 
         if (dragRange) {
-          this._previewStart = this._getCellCompareValue(dragRange.start);
-          this._previewEnd = this._getCellCompareValue(dragRange.end);
+          this._previewStart.set(this._getCellCompareValue(dragRange.start));
+          this._previewEnd.set(this._getCellCompareValue(dragRange.end));
         }
       }
     }
@@ -506,20 +510,20 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
     const longWeekdays = this._dateAdapter.getDayOfWeekNames('long');
 
     // Rotate the labels for days of the week based on the configured first day of the week.
-    let weekdays = longWeekdays.map((long, i) => {
+    const weekdays = longWeekdays.map((long, i) => {
       return {long, narrow: narrowWeekdays[i], id: uniqueIdCounter++};
     });
-    this._weekdays = weekdays.slice(firstDayOfWeek).concat(weekdays.slice(0, firstDayOfWeek));
+    this._weekdays.set(weekdays.slice(firstDayOfWeek).concat(weekdays.slice(0, firstDayOfWeek)));
   }
 
   /** Creates MatCalendarCells for the dates in this month. */
   private _createWeekCells() {
     const daysInMonth = this._dateAdapter.getNumDaysInMonth(this.activeDate);
     const dateNames = this._dateAdapter.getDateNames();
-    this._weeks = [[]];
-    for (let i = 0, cell = this._firstWeekOffset; i < daysInMonth; i++, cell++) {
+    const weeks: MatCalendarCell[][] = [[]];
+    for (let i = 0, cell = this._firstWeekOffset(); i < daysInMonth; i++, cell++) {
       if (cell == DAYS_PER_WEEK) {
-        this._weeks.push([]);
+        weeks.push([]);
         cell = 0;
       }
       const date = this._dateAdapter.createDate(
@@ -531,7 +535,7 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
       const ariaLabel = this._dateAdapter.format(date, this._dateFormats.display.dateA11yLabel);
       const cellClasses = this.dateClass ? this.dateClass(date, 'month') : undefined;
 
-      this._weeks[this._weeks.length - 1].push(
+      weeks[weeks.length - 1].push(
         new MatCalendarCell<D>(
           i + 1,
           dateNames[i],
@@ -543,6 +547,7 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
         ),
       );
     }
+    this._weeks.set(weeks);
   }
 
   /** Date filter for the month */
@@ -597,16 +602,17 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
   /** Sets the current range based on a model value. */
   private _setRanges(selectedValue: DateRange<D> | D | null) {
     if (selectedValue instanceof DateRange) {
-      this._rangeStart = this._getCellCompareValue(selectedValue.start);
-      this._rangeEnd = this._getCellCompareValue(selectedValue.end);
-      this._isRange = true;
+      this._rangeStart.set(this._getCellCompareValue(selectedValue.start));
+      this._rangeEnd.set(this._getCellCompareValue(selectedValue.end));
+      this._isRange.set(true);
     } else {
-      this._rangeStart = this._rangeEnd = this._getCellCompareValue(selectedValue);
-      this._isRange = false;
+      this._rangeStart.set(this._getCellCompareValue(selectedValue));
+      this._rangeEnd.set(this._rangeStart());
+      this._isRange.set(false);
     }
 
-    this._comparisonRangeStart = this._getCellCompareValue(this.comparisonStart);
-    this._comparisonRangeEnd = this._getCellCompareValue(this.comparisonEnd);
+    this._comparisonRangeStart.set(this._getCellCompareValue(this.comparisonStart));
+    this._comparisonRangeEnd.set(this._getCellCompareValue(this.comparisonEnd));
   }
 
   /** Gets whether a date can be selected in the month view. */
@@ -616,6 +622,7 @@ export class MatMonthView<D> implements AfterContentInit, OnChanges, OnDestroy {
 
   /** Clears out preview state. */
   private _clearPreview() {
-    this._previewStart = this._previewEnd = null;
+    this._previewStart.set(null);
+    this._previewEnd.set(null);
   }
 }

src/material/datepicker/multi-year-view.html

@@ -3,10 +3,10 @@
     <tr><th class="mat-calendar-table-header-divider" colspan="4"></th></tr>
   </thead>
   <tbody mat-calendar-body
-         [rows]="_years"
-         [todayValue]="_todayYear"
-         [startValue]="_selectedYear!"
-         [endValue]="_selectedYear!"
+         [rows]="_years()"
+         [todayValue]="_todayYear()"
+         [startValue]="_selectedYear()!"
+         [endValue]="_selectedYear()!"
          [numCols]="4"
          [cellAspectRatio]="4 / 7"
          [activeCell]="_getActiveCell()"