[lens] Generate esdocs queries from index pattern

x-pack/plugins/lens/public/indexpattern_plugin/indexpattern.test.tsx

@@ -91,6 +91,7 @@ describe('IndexPattern Data Source', () => {
 
           // Private
           operationType: 'value',
+          sourceField: 'op',
         },
       },
     };
@@ -158,6 +159,46 @@ describe('IndexPattern Data Source', () => {
     });
   });
 
+  describe('#toExpression', () => {
+    it('should generate an empty expression when no columns are selected', async () => {
+      const state = await indexPatternDatasource.initialize();
+      expect(indexPatternDatasource.toExpression(state)).toEqual('');
+    });
+
+    it('should generate an expression for a values query', async () => {
+      const queryPersistedState: IndexPatternPersistedState = {
+        currentIndexPatternId: '1',
+        columnOrder: ['col1', 'col2'],
+        columns: {
+          col1: {
+            operationId: 'op1',
+            label: 'My Op',
+            dataType: 'string',
+            isBucketed: false,
+
+            // Private
+            operationType: 'value',
+            sourceField: 'op',
+          },
+          col2: {
+            operationId: 'op2',
+            label: 'My Op 2',
+            dataType: 'number',
+            isBucketed: false,
+
+            // Private
+            operationType: 'value',
+            sourceField: 'op2',
+          },
+        },
+      };
+      const state = await indexPatternDatasource.initialize(queryPersistedState);
+      expect(indexPatternDatasource.toExpression(state)).toMatchInlineSnapshot(
+        `"esdocs index=\\"1\\" fields=\\"op, op2\\" sort=\\"op, DESC\\""`
+      );
+    });
+  });
+
   describe('#getPublicAPI', () => {
     let publicAPI: DatasourcePublicAPI;
 
@@ -262,6 +303,7 @@ describe('IndexPattern Data Source', () => {
               dataType: 'date',
               isBucketed: false,
               operationType: 'value',
+              sourceField: 'timestamp',
             },
           },
           columnOrder: ['col1', 'col2'],

x-pack/plugins/lens/public/indexpattern_plugin/indexpattern.tsx

@@ -24,6 +24,7 @@ interface IndexPatternColumn {
 
   // Private
   operationType: OperationType;
+  sourceField: string;
 }
 
 export interface IndexPattern {
@@ -107,6 +108,7 @@ export function IndexPatternDimensionPanel(props: IndexPatternDimensionPanelProp
     isBucketed: false,
 
     operationType: 'value' as OperationType,
+    sourceField: field.name,
   }));
 
   const filteredColumns = columns.filter(col => {
@@ -196,7 +198,16 @@ export function getIndexPatternDatasource(chrome: Chrome, toastNotifications: To
     },
 
     toExpression(state: IndexPatternPrivateState) {
-      return `${JSON.stringify(state.columns)}`;
+      if (state.columnOrder.length === 0) {
+        return '';
+      }
+
+      const fieldNames = state.columnOrder.map(col => state.columns[col].sourceField);
+      const expression = `esdocs index="${state.currentIndexPatternId}" fields="${fieldNames.join(
+        ', '
+      )}" sort="${fieldNames[0]}, DESC"`;
+
+      return expression;
     },
 
     renderDataPanel(

x-pack/plugins/lens/public/xy_visualization_plugin/xy_visualization.tsx

@@ -38,6 +38,14 @@ export const xyVisualization: Visualization<XyVisualizationState, XyVisualizatio
           }}
           render={props.datasource.renderDimensionPanel}
         />
+        <NativeRenderer
+          nativeProps={{
+            columnId: 'col2',
+            filterOperations: (op: Operation) => true,
+            suggestedOrder: 2,
+          }}
+          render={props.datasource.renderDimensionPanel}
+        />
       </div>,
       domElement
     );