feat: Add option filterCaseSensitive

You can use on specific control or directly on default settings

src/ngx-tree-select/src/components/tree-select.component.ts

@@ -77,6 +77,14 @@ export class TreeSelectComponent implements ControlValueAccessor {
     return this.svc.Configuration.allowMultiple;
   }
 
+  @Input()
+  public set filterCaseSensitive(value: boolean) {
+    this.svc.setConfiguration((opt) => opt.filterCaseSensitive = value, true);
+  }
+  public get filterCaseSensitive(): boolean {
+    return this.svc.Configuration.filterCaseSensitive;
+  }
+
   @Input()
   public set maxVisibleItemCount(value: number) {
     this.svc.setConfiguration((opt) => opt.maxVisibleItemCount = value, true);
@@ -129,6 +137,11 @@ export class TreeSelectComponent implements ControlValueAccessor {
         true :
         defaultOpts.allowFilter
     );
+    this.filterCaseSensitive = (
+      (defaultOpts.filterCaseSensitive === undefined || defaultOpts.filterCaseSensitive === null) ?
+        false :
+        defaultOpts.filterCaseSensitive
+    );
     this.filterPlaceholder = (defaultOpts.filterPlaceholder || 'Type here for filtering items...');
     this.idField = (defaultOpts.idField || 'id');
     this.textField = (defaultOpts.textField || 'id');
@@ -235,7 +248,9 @@ export class TreeSelectComponent implements ControlValueAccessor {
         result = this.ProcessMatchFilterTreeItem(child, filter) || result;
       }
     }
-    tree.matchFilter = (tree.id.indexOf(filter) > -1 || tree.text.indexOf(filter) > -1 || result);
+    tree.matchFilter = this.filterCaseSensitive ? 
+                       (tree.id.indexOf(filter) > -1 || tree.text.indexOf(filter) > -1 || result) :
+                       (tree.id.toLowerCase().indexOf(filter.toLowerCase()) > -1 || tree.text.toLowerCase().indexOf(filter.toLowerCase()) > -1 || result);
 
     return tree.matchFilter;
   }

src/ngx-tree-select/src/models/select-option.ts

@@ -8,6 +8,7 @@ export class SelectOption {
   public model: any[] | any;
   public isOpen = false;
   public filter = '';
+  public filterCaseSensitive = false;
   public allowParentSelection = false;
   public maxVisibleItemCount: number;
 

src/ngx-tree-select/src/models/tree-select-default-options.ts

@@ -9,4 +9,5 @@ export class TreeSelectDefaultOptions {
   public idField?: string;
   public textField?: string;
   public childrenField?: string;
+  public filterCaseSensitive?: boolean;
 }