Support variable interpolation

Author: nineinchnick

README.md

@@ -43,6 +43,38 @@ Plugin supports the following marcos:
 
 A description of macros is available by typing their names in Raw Editor
 
+## Templating
+
+### Using Variables in Queries
+
+Template variable values are only quoted when the template variable is a `multi-value`.
+
+If the variable is a multi-value variable then use the `IN` comparison operator
+rather than `=` to match against multiple values.
+
+Example with a template variable named hostname:
+
+```sql
+SELECT
+  atimestamp as time,
+  aint as value
+FROM table
+WHERE $__timeFilter(atimestamp) and hostname in($hostname)
+ORDER BY atimestamp ASC
+```
+
+### Disabling quoting for multi-value variables
+
+Grafana automatically creates a quoted, comma-separated string for multi-value variables.
+For example: if `server01` and `server02` are selected then it will be formatted as:
+`'server01', 'server02'`. To disable quoting, use the `csv` formatting option for variables:
+
+```
+${servers:csv}
+```
+
+Read more about variable formatting options in the [Variables](https://grafana.com/docs/grafana/latest/variables/#advanced-formatting-options) documentation.
+
 # Contributing
 
 If you have any idea for an improvement or found a bug do not hesitate to open an issue or submit a pull request.

src/datasource.ts

@@ -1,12 +1,15 @@
-import { DataSourceInstanceSettings } from '@grafana/data';
-import { DataSourceWithBackend, getBackendSrv, toDataQueryError } from '@grafana/runtime';
+import { DataSourceInstanceSettings, ScopedVars } from '@grafana/data';
+import { DataSourceWithBackend, getBackendSrv, getTemplateSrv, toDataQueryError } from '@grafana/runtime';
 import { TrinoDataSourceOptions, TrinoQuery } from './types';
 import { lastValueFrom, of } from 'rxjs';
 import { catchError, mapTo } from 'rxjs/operators';
+import { map } from 'lodash';
 
 export class DataSource extends DataSourceWithBackend<TrinoQuery, TrinoDataSourceOptions> {
   constructor(instanceSettings: DataSourceInstanceSettings<TrinoDataSourceOptions>) {
     super(instanceSettings);
+    // give interpolateQueryStr access to this
+    this.interpolateQueryStr = this.interpolateQueryStr.bind(this);
   }
 
   testDatasource(): Promise<any> {
@@ -40,4 +43,35 @@ export class DataSource extends DataSourceWithBackend<TrinoQuery, TrinoDataSourc
         )
     );
   }
+
+  applyTemplateVariables(query: TrinoQuery, scopedVars: ScopedVars): Record<string, any> {
+    query.rawSQL = getTemplateSrv().replace(query.rawSQL, scopedVars, this.interpolateQueryStr);
+    return query;
+  }
+
+  interpolateQueryStr(value: any, variable: { multi: any; includeAll: any }, defaultFormatFn: any) {
+    // if no multi or include all do not regexEscape
+    if (!variable.multi && !variable.includeAll) {
+      return this.escapeLiteral(value);
+    }
+
+    if (typeof value === 'string') {
+      return this.quoteLiteral(value);
+    }
+
+    const escapedValues = map(value, this.quoteLiteral);
+    return escapedValues.join(',');
+  }
+
+  quoteIdentifier(value: any) {
+    return '"' + String(value).replace(/"/g, '""') + '"';
+  }
+
+  quoteLiteral(value: any) {
+    return "'" + String(value).replace(/'/g, "''") + "'";
+  }
+
+  escapeLiteral(value: any) {
+    return String(value).replace(/'/g, "''");
+  }
 }

src/specs/datasource.test.ts

@@ -2,13 +2,27 @@ import { of } from 'rxjs';
 import { TestScheduler } from 'rxjs/testing';
 
 import { dataFrameToJSON, DataSourceInstanceSettings, dateTime, MutableDataFrame } from '@grafana/data';
-import { BackendSrv, DataSourceSrv, FetchResponse, setBackendSrv, setDataSourceSrv } from '@grafana/runtime';
+import {
+  BackendSrv,
+  DataSourceSrv,
+  FetchResponse,
+  setBackendSrv,
+  setDataSourceSrv,
+  TemplateSrv,
+  setTemplateSrv,
+} from '@grafana/runtime';
 
 import { DataSource } from '../datasource';
 import { TrinoDataSourceOptions } from '../types';
 
 const mockBackend = { fetch: () => {} };
 setBackendSrv(mockBackend as unknown as BackendSrv);
+const mockTemplate = {
+  replace: (target: any) => {
+    return target;
+  },
+};
+setTemplateSrv(mockTemplate as unknown as TemplateSrv);
 const mockDataSource = {
   getInstanceSettings: () => ({ id: 8674 }),
 };
@@ -17,6 +31,7 @@ setDataSourceSrv(mockDataSource as unknown as DataSourceSrv);
 jest.mock('@grafana/runtime', () => ({
   ...(jest.requireActual('@grafana/runtime') as unknown as object),
   getBackendSrv: () => mockBackend,
+  getTemplateSrv: () => mockTemplate,
   getDataSourceSrv: () => mockDataSource,
 }));