Merge pull request #133 from QuantStack/ky/uniqueview

unique values from view

Author: kaiayoung

src/core/view.ts

@@ -156,6 +156,23 @@ class View {
     }
   }
 
+  /**
+   * Returns a Promise that resolves to an array of unique values contained in
+   * the provided column index.
+   *
+   * @param columnIndex - The index to retrieve unique values for.
+   */
+  async uniqueValues(region: DataModel.CellRegion, columnIndex: number): Promise<any[]> {
+    return new Promise((resolve, reject) => {
+      const columnName = this.metadata(region, 0, columnIndex)['name'];
+      let uniqueVals = new Set();
+      for (let row of this.dataset) {
+        uniqueVals.add(row[columnName]);
+      };
+      resolve(Array.from(uniqueVals));
+    });
+  }
+
   private readonly _data: View.DataSource;
   private readonly _bodyFields: ViewBasedJSONModel.IField[];
   private readonly _headerFields: ViewBasedJSONModel.IField[];

src/core/viewbasedjsonmodel.ts

@@ -335,6 +335,7 @@ export class ViewBasedJSONModel extends MutableDataModel {
    * Returns a Promise that resolves to an array of unique values contained in
    * the provided column index.
    *
+   * @param region - The CellRegion to retrieve unique values for.
    * @param columnIndex - The index to retrieve unique values for.
    */
   async uniqueValues(region: DataModel.CellRegion, columnIndex: number): Promise<any[]> {
@@ -348,6 +349,17 @@ export class ViewBasedJSONModel extends MutableDataModel {
     });
   }
 
+  /**
+   * Returns a Promise that resolves to an array of unique values contained in
+   * the provided column index after all transforms have been applied.
+   * 
+   * @param region - The CellRegion to retrieve unique values for.
+   * @param columnIndex - The index to retrieve unique values for.
+   */
+  async uniqueValuesVisible(region: DataModel.CellRegion, columnIndex: number): Promise<any[]> {
+    return this._currentView.uniqueValues(region, columnIndex);
+  }
+
   get transformStateChanged(): ISignal<this, TransformStateManager.IEvent> {
     return this._transformSignal;
   }