feat: add cssStyler option to use typed CSSStyleDeclaration props

demo/src/options/options26.html

@@ -1,7 +1,7 @@
 <div class="row mb-2">
   <div class="col-md-12 title-desc">
     <h2 class="bd-title">
-      The Styler
+      The Styler / CSS Styler
       <span class="float-end links">
         Code <span class="fa fa-link"></span>
         <span class="small">
@@ -66,4 +66,25 @@ <h2 class="bd-title">
       </select>
     </div>
   </div>
+
+  <div class="mb-3 row">
+    <label class="col-sm-2"> CSS Styler </label>
+
+    <div class="col-sm-10">
+      <select id="select3" multiple="multiple" class="full-width" data-test="select3">
+        <option value="1">January</option>
+        <option value="2">February</option>
+        <option value="3">March</option>
+        <option value="4">April</option>
+        <option value="5">May</option>
+        <option value="6">June</option>
+        <option value="7">July</option>
+        <option value="8">August</option>
+        <option value="9">September</option>
+        <option value="10">October</option>
+        <option value="11">November</option>
+        <option value="12">December</option>
+      </select>
+    </div>
+  </div>
 </div>

demo/src/options/options26.ts

@@ -3,6 +3,7 @@ import { multipleSelect, OptionRowData, OptGroupRowData, MultipleSelectInstance
 export default class Example {
   ms1?: MultipleSelectInstance;
   ms2?: MultipleSelectInstance;
+  ms3?: MultipleSelectInstance;
 
   mount() {
     this.ms1 = multipleSelect('#basic', {
@@ -28,13 +29,27 @@ export default class Example {
         return null;
       },
     }) as MultipleSelectInstance;
+
+    this.ms3 = multipleSelect('#select3', {
+      cssStyler: (row: OptionRowData | OptGroupRowData) => {
+        if (+(row?.value ?? 0) === 2) {
+          return { backgroundColor: '#6fbeff', color: '#0014ff', fontStyle: 'italic' } as CSSStyleDeclaration;
+        }
+        if (+(row?.value ?? 0) === 4) {
+          return { backgroundColor: '#972727', color: '#fff' } as CSSStyleDeclaration;
+        }
+        return null;
+      },
+    }) as MultipleSelectInstance;
   }
 
   unmount() {
     // destroy ms instance(s) to avoid DOM leaks
     this.ms1?.destroy();
     this.ms2?.destroy();
+    this.ms3?.destroy();
     this.ms1 = undefined;
     this.ms2 = undefined;
+    this.ms3 = undefined;
   }
 }

lib/src/MultipleSelectInstance.ts

@@ -15,7 +15,7 @@ import {
   toggleElement,
 } from './utils/domUtils';
 import type { HtmlElementPosition } from './utils/domUtils';
-import type { MultipleSelectOption } from './interfaces/multipleSelectOption.interface';
+import type { CSSStyleDeclarationWritable, MultipleSelectOption } from './interfaces/multipleSelectOption.interface';
 import type { MultipleSelectLocales, OptGroupRowData, OptionDataObject, OptionRowData } from './interfaces';
 import { BindingEventService, VirtualScroll } from './services';
 
@@ -576,6 +576,12 @@ export class MultipleSelectInstance {
     }
     applyParsedStyleToElement(liElm, style);
 
+    const customStyleCss = this.options.cssStyler?.(row);
+    if (customStyleCss) {
+      for (const styleProp of Object.keys(customStyleCss)) {
+        liElm.style[styleProp as CSSStyleDeclarationWritable] = customStyleCss[styleProp as CSSStyleDeclarationWritable];
+      }
+    }
     const labelClasses = `${row.disabled ? 'disabled' : ''}`;
     const labelElm = document.createElement('label');
     if (labelClasses) {

lib/src/interfaces/multipleSelectOption.interface.ts

@@ -7,6 +7,16 @@ export interface MultipleSelectView {
   instance: any;
 }
 
+export type CSSStyleDeclarationReadonly =
+  | 'length'
+  | 'parentRule'
+  | 'getPropertyPriority'
+  | 'getPropertyValue'
+  | 'item'
+  | 'removeProperty'
+  | 'setProperty';
+export type CSSStyleDeclarationWritable = keyof Omit<CSSStyleDeclaration, CSSStyleDeclarationReadonly>;
+
 export interface MultipleSelectOption extends MultipleSelectLocale {
   /** @deprecated @alias `displayTitle` Add a title. By default this option is set to false. */
   addTitle?: boolean;
@@ -176,7 +186,10 @@ export interface MultipleSelectOption extends MultipleSelectLocale {
   /** Customize the filter method, for example we use startWith */
   customFilter(options: LabelFilter | TextFilter): boolean;
 
-  /** The item styler function, return style string to custom the item style such as background: red. The function take one parameter: value. */
+  /** The item styler function, return style string to customize the item style such as background: red. The function take one parameter: value. */
+  cssStyler?: (value: OptionRowData | OptGroupRowData) => CSSStyleDeclaration | null;
+
+  /** @deprecated @use `cssStyler`. The item styler function, return style string to customize the item style such as background: red. The function take one parameter: value. */
   styler: (value: OptionRowData | OptGroupRowData) => string | boolean | null;
 
   /** Returns HTML label attribute of a DOM element */

playwright/e2e/options26.spec.ts

@@ -1,6 +1,6 @@
 import { test, expect } from '@playwright/test';
 
-test.describe('Options 26 - The Styler', () => {
+test.describe('Options 26 - The Styler / CSS Styler', () => {
   test.beforeEach(async ({ page }) => {
     await page.goto('#/options26');
   });
@@ -32,4 +32,21 @@ test.describe('Options 26 - The Styler', () => {
     const dropLoc2 = await page.locator('[data-test=select2] .ms-choice span', { hasText: '[Group 1: Option 1]' });
     await dropLoc2.waitFor();
   });
+
+  test('third select has February & April with custom CSS styler', async ({ page }) => {
+    await page.locator('[data-test=select3].ms-parent').click();
+    const optionLoc2 = await page.locator('[data-test=select3] .ms-drop ul li').nth(1);
+    optionLoc2.click();
+    expect(optionLoc2).toHaveText('February');
+    await expect(optionLoc2).toHaveCSS('color', 'rgb(0, 20, 255)');
+    await expect(optionLoc2).toHaveCSS('background-color', 'rgb(111, 190, 255)');
+
+    const optionLoc4 = await page.locator('[data-test=select3] .ms-drop ul li').nth(3);
+    optionLoc4.click();
+    expect(optionLoc4).toHaveText('April');
+    await expect(optionLoc4).toHaveCSS('color', 'rgb(255, 255, 255)');
+    await expect(optionLoc4).toHaveCSS('background-color', 'rgb(151, 39, 39)');
+    const selectedText3 = page.locator('[data-test=select3] .ms-choice span', { hasText: 'February, April' });
+    await selectedText3.waitFor();
+  });
 });