fix: interface for controls/plugins w/Formatter might return HTMLElement (#911)

Author: ghiscoding

src/controls/slick.columnmenu.ts

@@ -157,7 +157,7 @@ export class SlickColumnMenu {
 
       const labelElm = document.createElement('label');
       labelElm.htmlFor = `${this._gridUid}colpicker-${columnId}`;
-      labelElm.innerHTML = this.grid.sanitizeHtmlString(columnLabel);
+      labelElm.innerHTML = this.grid.sanitizeHtmlString(columnLabel instanceof HTMLElement ? columnLabel.innerHTML : columnLabel);
       liElm.appendChild(labelElm);
       this._listElm.appendChild(liElm);
     }

src/controls/slick.columnpicker.ts

@@ -158,7 +158,7 @@ export class SlickColumnPicker {
 
       const labelElm = document.createElement('label');
       labelElm.htmlFor = `${this._gridUid}colpicker-${columnId}`;
-      labelElm.innerHTML = this.grid.sanitizeHtmlString(columnLabel);
+      labelElm.innerHTML = this.grid.sanitizeHtmlString(columnLabel instanceof HTMLElement ? columnLabel.innerHTML : columnLabel);
       liElm.appendChild(labelElm);
       this._listElm.appendChild(liElm);
     }

src/controls/slick.gridmenu.ts

@@ -592,7 +592,7 @@ export class SlickGridMenu {
 
       const labelElm = document.createElement('label');
       labelElm.htmlFor = `${this._gridUid}-gridmenu-colpicker-${columnId}`;
-      labelElm.innerHTML = this.grid.sanitizeHtmlString(columnLabel || '');
+      labelElm.innerHTML = this.grid.sanitizeHtmlString((columnLabel instanceof HTMLElement ? columnLabel.innerHTML : columnLabel) || '');
       liElm.appendChild(labelElm);
       this._listElm.appendChild(liElm);
     }

src/models/columnPicker.interface.ts

@@ -33,7 +33,7 @@ export interface ColumnPickerOption {
   syncResizeTitle?: string;
 
   /** Callback method to override the column name output used by the ColumnPicker/GridMenu. */
-  headerColumnValueExtractor?: (column: Column, gridOptions?: GridOption) => string;
+  headerColumnValueExtractor?: (column: Column, gridOptions?: GridOption) => string | HTMLElement;
 }
 
 export interface OnColumnsChangedArgs {

src/models/gridMenuOption.interface.ts

@@ -86,7 +86,7 @@ export interface GridMenuOption {
   // action/override callbacks
 
   /** Callback method to override the column name output used by the ColumnPicker/GridMenu. */
-  headerColumnValueExtractor?: (column: Column, gridOptions?: GridOption) => string;
+  headerColumnValueExtractor?: (column: Column, gridOptions?: GridOption) => string | HTMLElement;
 
   /** Callback method that user can override the default behavior of enabling/disabling an item from the list. */
   menuUsabilityOverride?: (args: MenuCallbackArgs<any>) => boolean;