make defaults for groupBy configurable

We do not know which fields exist at compile time.
But it is a great help to have some pre-selected
fields in groupBy.
Solved by adding a configuration option.

pdb-js/src/app/plot.service.ts

@@ -9,18 +9,10 @@ import { Observable } from 'rxjs/Observable';
 export class PlotService {
 
   plotTypes: Array<PlotType>;
-  
-  tagFields: Array<TagField>;
-  
+    
   constructor(private http: HttpClient) {
     this.plotTypes = new Array<PlotType>();
-    this.plotTypes.push(new PlotType(
-      "SCATTER",
-      "Scatter", 
-      "scatter-chart2", 
-      true, 
-      DataType.Time, 
-      DataType.Duration));
+    this.plotTypes.push(new PlotType("SCATTER","Scatter","scatter-chart2",true,DataType.Time,DataType.Duration));
     this.plotTypes.push(new PlotType("HEATMAP", "Heatmap", "heatmap", false, DataType.Other, DataType.Other));
     this.plotTypes.push(new PlotType("CONTOUR", "Contour", "contour-chart", false, DataType.Time, DataType.Duration));
     this.plotTypes.push(new PlotType("CUM_DISTRIBUTION", "Cumulative Distribution", "cumulative-distribution-chart", true, DataType.Percent, DataType.Duration));
@@ -33,8 +25,6 @@ export class PlotService {
     this.plotTypes.push(new PlotType("PIE", "Pie", "pie-chart", false, DataType.Other, DataType.Other));
     this.plotTypes.push(new PlotType("BAR", "Bar", "bar-chart", false, DataType.Other, DataType.Other));
     this.plotTypes.push(new PlotType("STEP_FIT", "Step Fit", "step-fit", false, DataType.Other, DataType.Other));
-    
-    this.tagFields = new Array<TagField>();
   }
   
   ngOnInit() {
@@ -45,16 +35,8 @@ export class PlotService {
     return this.plotTypes.filter(plotType => plotType.active);
   }
   
-  getTagFields(): Array<TagField> {
-    const that = this;
-    this.http.get('//'+window.location.hostname+':8080/fields').subscribe(data => {
-      if (data instanceof Array){
-        data.forEach(function(name) {
-          that.tagFields.push(new TagField(name));
-        });
-      }
-    });
-    return this.tagFields;
+  getTagFields(): Observable<Array<string>> {
+    return this.http.get<Array<string>>('//'+window.location.hostname+':8080/fields');
   }
   
   autocomplete(query: string, caretIndex: number): Observable<AutocompleteResult>
@@ -72,6 +54,10 @@ export class PlotService {
     console.log("send plot request: "+  JSON.stringify(plotRequest));
     return this.http.post<PlotResponse>('//'+window.location.hostname+':8080/plots', plotRequest);
   }
+  
+  getFilterDefaults(): Observable<FilterDefaults>{
+    return this.http.get<FilterDefaults>('//'+window.location.hostname+':8080/filters/defaults')
+  }
 }
 
 
@@ -181,3 +167,7 @@ export class DataSeriesStats {
   plottedValues : number;
 }
 
+export class FilterDefaults {
+  groupBy: Array<string>;
+  fields: Array<string>; 
+}

pdb-js/src/app/visualization-page/visualization-page.component.ts

@@ -1,11 +1,11 @@
 import { Component, OnInit, ViewChild } from '@angular/core';
-import { PlotService, PlotType, PlotRequest, PlotResponse } from '../plot.service';
+import { PlotService, PlotType, PlotRequest, PlotResponse, TagField, FilterDefaults  } from '../plot.service';
 import { Observable } from 'rxjs/Observable';
 import { FormControl, Validators } from '@angular/forms';
 import { LimitByComponent } from '../limit-by/limit-by.component';
 import { YAxisRangeComponent } from '../y-axis-range/y-axis-range.component';
 import { QueryAutocompleteComponent } from '../query-autocomplete/query-autocomplete.component';
-import {PlotViewComponent, SelectionRange, DateAnchor } from '../plot-view/plot-view.component'
+import {PlotViewComponent, SelectionRange, DateAnchor} from '../plot-view/plot-view.component'
 import * as moment from 'moment';
 
 @Component({
@@ -27,9 +27,9 @@ export class VisualizationPageComponent implements OnInit {
   selectedCombinePlotType = new FormControl('');
   combinePlotTypes: Array<any>;
   
-  tagFields: Array<any>;
+  tagFields: Array<TagField> = new Array<TagField>();
   
-  groupBy: Array<any> = [];
+  groupBy = new Array<TagField>();
   
   @ViewChild(LimitByComponent, {static: false})
   private limitbycomponent : LimitByComponent;
@@ -62,7 +62,14 @@ export class VisualizationPageComponent implements OnInit {
     
     this.combinePlotTypes = this.getCombinablePlotTypes(this.selectedPlotType.value);
     
-    this.tagFields = this.plotService.getTagFields();
+    that.plotService.getFilterDefaults().subscribe(function(filterDefaults) {
+    
+      filterDefaults.fields.forEach(function(name) {
+        that.tagFields.push(new TagField(name));
+      });
+    
+      that.groupBy = that.tagFields.filter(val => filterDefaults.groupBy.includes(val.name));
+    });
     this.yAxisScale = "LOG10";
     
     this.selectedPlotType.valueChanges.subscribe(function(selectedMainPlotType){