Add Expiry Indicator functionality with configuration and command set

- Implemented ExpiryItemService to manage expiry date logic for list items.
- Created ExpiryModels to define types and structures for expiry configurations and rules.
- Added RestError utility for handling API response errors.
- Developed ExpiryIndicatorFieldCustomizer to display expiry information in list views.
- Introduced ExpiryIndicatorCommandSet for extending expiry dates and managing settings.
- Added settings dialog for configuring expiry settings.
- Implemented localization support for English and German languages.
- Added TypeScript configuration files for project setup.
- Included TSLint configuration for code quality enforcement.

src/extensions/expiryIndicator/ExpiryIndicatorFieldCustomizer.ts

@@ -0,0 +1,157 @@
+import { override } from '@microsoft/decorators';
+import {
+  BaseFieldCustomizer,
+  IFieldCustomizerCellEventParameters
+} from '@microsoft/sp-listview-extensibility';
+import { evaluateExpiry, formatDate, parseSharePointDate } from '../../common/ExpiryDateCalculator';
+import { ExpiryConfigService } from '../../common/ExpiryConfigService';
+import { ExpiryItemService } from '../../common/ExpiryItemService';
+import {
+  createDefaultConfig,
+  IExpiryConfig,
+  IExpiryEvaluation,
+  IItemDateValues,
+  resolveBehavior
+} from '../../common/ExpiryModels';
+import styles from './ExpiryIndicatorFieldCustomizer.module.scss';
+import * as strings from 'ExpiryIndicatorStrings';
+
+export interface IExpiryIndicatorFieldCustomizerProperties {
+}
+
+export default class ExpiryIndicatorFieldCustomizer
+  extends BaseFieldCustomizer<IExpiryIndicatorFieldCustomizerProperties> {
+
+  private _config: IExpiryConfig = createDefaultConfig();
+  private _itemService: ExpiryItemService;
+  private _itemCache: { [id: string]: Promise<IItemDateValues> } = {};
+
+  @override
+  public onInit(): Promise<void> {
+    if (!this.context.pageContext.list) {
+      return Promise.resolve();
+    }
+
+    const service: ExpiryConfigService = new ExpiryConfigService(
+      this.context.spHttpClient,
+      this.context.pageContext.web.absoluteUrl
+    );
+
+    this._itemService = new ExpiryItemService(
+      this.context.spHttpClient,
+      this.context.pageContext.web.absoluteUrl,
+      this.context.pageContext.list.id.toString()
+    );
+
+    return service.getConfig(this.context.pageContext.list.id.toString())
+      .then((config: IExpiryConfig): void => { this._config = config; })
+      .catch((): void => { this._config = createDefaultConfig(); });
+  }
+
+  @override
+  public onRenderCell(event: IFieldCustomizerCellEventParameters): void {
+    this._clear(event.domElement);
+
+    const expiry: Date | undefined = parseSharePointDate(event.fieldValue);
+    const createdValue: any = event.listItem && event.listItem.getValueByName
+      ? event.listItem.getValueByName(this._config.baseField)
+      : undefined;
+    const created: Date | undefined = parseSharePointDate(createdValue);
+
+    const idValue: any = event.listItem && event.listItem.getValueByName
+      ? (event.listItem.getValueByName('ID') || event.listItem.getValueByName('Id'))
+      : undefined;
+    const itemId: number = Number(idValue);
+
+    if (itemId > 0 && this._itemService) {
+      const requestKey: string = String(itemId);
+      event.domElement.setAttribute('data-expiry-item-id', requestKey);
+      this._renderNeutral(event.domElement, strings.Loading);
+      if (!this._itemCache[requestKey]) {
+        this._itemCache[requestKey] = this._itemService.getItemDates(itemId, this._config);
+      }
+
+      this._itemCache[requestKey].then((item: IItemDateValues): void => {
+        if (event.domElement.getAttribute('data-expiry-item-id') !== requestKey) {
+          return;
+        }
+        this._clear(event.domElement);
+        this._renderValues(event.domElement, item.created, item.expiry, item.fieldValues);
+      }).catch((): void => {
+        if (event.domElement.getAttribute('data-expiry-item-id') === requestKey) {
+          this._clear(event.domElement);
+          this._renderValues(event.domElement, created, expiry, {});
+        }
+      });
+      return;
+    }
+
+    this._renderValues(event.domElement, created, expiry, {});
+  }
+
+  @override
+  public onDisposeCell(event: IFieldCustomizerCellEventParameters): void {
+    this._clear(event.domElement);
+    super.onDisposeCell(event);
+  }
+
+  private _renderEvaluation(container: HTMLElement, evaluation: IExpiryEvaluation): void {
+    const wrapper: HTMLSpanElement = document.createElement('span');
+    wrapper.className = styles.cell + (evaluation.wasCalculated ? ' ' + styles.calculated : '');
+
+    if (evaluation.matchedRule) {
+      wrapper.style.backgroundColor = evaluation.matchedRule.backgroundColor;
+      wrapper.style.color = evaluation.matchedRule.textColor;
+    }
+
+    const date: HTMLSpanElement = document.createElement('span');
+    date.className = styles.date;
+    date.textContent = formatDate(evaluation.effectiveExpiryDate);
+    wrapper.appendChild(date);
+
+    if (evaluation.matchedRule && evaluation.matchedRule.label) {
+      const label: HTMLSpanElement = document.createElement('span');
+      label.className = styles.label;
+      label.textContent = evaluation.matchedRule.label;
+      wrapper.appendChild(label);
+    }
+
+    const calculationHint: string = evaluation.wasCalculated ? ' – ' + strings.CalculatedHint : '';
+    wrapper.title = strings.DaysUntilExpiry.replace('{0}', String(evaluation.daysUntilExpiry)) + calculationHint;
+    container.appendChild(wrapper);
+  }
+
+  private _renderValues(
+    container: HTMLElement,
+    created: Date | undefined,
+    expiry: Date | undefined,
+    fieldValues: { [fieldName: string]: any }
+  ): void {
+    if (!expiry && !created) {
+      this._renderNeutral(container, this._config.nullText);
+      return;
+    }
+
+    const evaluation: IExpiryEvaluation = evaluateExpiry(
+      created || expiry as Date,
+      expiry,
+      this._config,
+      undefined,
+      resolveBehavior(this._config, fieldValues)
+    );
+    this._renderEvaluation(container, evaluation);
+  }
+
+  private _renderNeutral(container: HTMLElement, text: string): void {
+    const wrapper: HTMLSpanElement = document.createElement('span');
+    wrapper.className = styles.cell + ' ' + styles.neutral;
+    wrapper.textContent = text;
+    container.appendChild(wrapper);
+  }
+
+  private _clear(container: HTMLElement): void {
+    while (container.firstChild) {
+      container.removeChild(container.firstChild);
+    }
+  }
+}