Dashboard: Support Variables in "Filter by Name" Transformation (#51804)

packages/grafana-data/src/transformations/transformers/filter.ts

@@ -22,9 +22,23 @@ export const filterFieldsTransformer: DataTransformerInfo<FilterOptions> = {
    * Return a modified copy of the series.  If the transform is not or should not
    * be applied, just return the input series
    */
-  operator: (options: FilterOptions) => (source) => {
+  operator: (options: FilterOptions, replace) => (source) => {
     if (!options.include && !options.exclude) {
-      return source.pipe(noopTransformer.operator({}));
+      return source.pipe(noopTransformer.operator({}, replace));
+    }
+
+    if (replace) {
+      if (typeof options.include?.options === 'string') {
+        options.include.options = replace(options.include?.options);
+      } else if (typeof options.include?.options?.pattern === 'string') {
+        options.include.options.pattern = replace(options.include?.options.pattern);
+      }
+
+      if (typeof options.exclude?.options === 'string') {
+        options.exclude.options = replace(options.exclude?.options);
+      } else if (typeof options.exclude?.options?.pattern === 'string') {
+        options.exclude.options.pattern = replace(options.exclude?.options.pattern);
+      }
     }
 
     return source.pipe(

packages/grafana-data/src/transformations/transformers/filterByName.test.ts

@@ -1,4 +1,5 @@
 import { toDataFrame } from '../../dataframe/processDataFrame';
+import { ScopedVars } from '../../types';
 import { FieldType } from '../../types/dataFrame';
 import { mockTransformationsRegistry } from '../../utils/tests/mockTransformationsRegistry';
 import { transformDataFrame } from '../transformDataFrame';
@@ -195,5 +196,38 @@ describe('filterByName transformer', () => {
         expect(filtered.fields[0].name).toBe('B');
       });
     });
+
+    it('uses template variable substituion', async () => {
+      const cfg = {
+        id: DataTransformerID.filterFieldsByName,
+        options: {
+          include: {
+            pattern: '/^$var1/',
+          },
+        },
+        replace: (target: string | undefined, scopedVars?: ScopedVars, format?: string | Function): string => {
+          if (!target) {
+            return '';
+          }
+          const variables: ScopedVars = {
+            var1: {
+              value: 'startsWith',
+              text: 'Test',
+            },
+          };
+          for (const key of Object.keys(variables)) {
+            return target.replace(`$${key}`, variables[key].value);
+          }
+          return target;
+        },
+      };
+
+      await expect(transformDataFrame([cfg], [seriesWithNamesToMatch])).toEmitValuesWith((received) => {
+        const data = received[0];
+        const filtered = data[0];
+        expect(filtered.fields.length).toBe(2);
+        expect(filtered.fields[0].name).toBe('startsWithA');
+      });
+    });
   });
 });

packages/grafana-data/src/transformations/transformers/filterByName.ts

@@ -20,12 +20,15 @@ export const filterFieldsByNameTransformer: DataTransformerInfo<FilterFieldsByNa
    * Return a modified copy of the series.  If the transform is not or should not
    * be applied, just return the input series
    */
-  operator: (options) => (source) =>
+  operator: (options, replace) => (source) =>
     source.pipe(
-      filterFieldsTransformer.operator({
+      filterFieldsTransformer.operator(
+        {
           include: getMatcherConfig(options.include),
           exclude: getMatcherConfig(options.exclude),
-      })
+        },
+        replace
+      )
     ),
 };