aswi2021codebakers-gitlab/src/app/shared/graph-loading/graphloader.ts @ c17d9fd3

import {Graph} from './graph';
import {EmptyGraph} from "./emptygraph";
import {SingleGraph} from "./singlegraph";
import {MultiGraph} from "./multigraph";

declare var require: any



export class GraphLoader {

  /**
   * Loads graph with default interval value (e.g. for observation service)
   * @param sensors array of sensors to display
   * @param data source of values for vega graph
   * @param legendInfo source of legend info for graph (e.g. sensor phenomenon)
   * @param element name of html element for graph display
   * @param isAnalytics true/false analytics/observations
   */
  static getGraph(sensors, data, legendInfo, element, isAnalytics) {
    this.getGraphWithInterval(sensors, data, 1800000, legendInfo, element, isAnalytics);
  }



  /**
   * Loads graph with specified interval (e.g. for analytics service)
   * @param sensors array of sensors to display
   * @param data source of values for vega graph
   * @param interval default graph interval used for different purposes (in milliseconds) (see timeWindow and maxTimeDifference in vega specification)
   * @param legendInfo source of legend info for graph (e.g. sensor phenomenon)
   * @param element name of html element for graph display
   * @param isAnalytics true/false analytics/observations
   */
  static getGraphWithInterval(sensors, data, interval, legendInfo, element, isAnalytics) {
    //gets uses sensors array to get graph type
    //then gets configuration and specification from corresponding class
    let graph = this.getGraphType(sensors,data, interval, legendInfo, isAnalytics);
    let config = graph.getConfig();
    let spec = graph.getSpec();

   //then displays the graph
    this.showGraph(spec, config, element);
  }


  /**
   * Create graph of specific type according to selected sensors
   * @param sensors array of sensors to display
   * @param data source of values for vega graph
   * @param interval default graph interval used for different purposes (in milliseconds) (see timeWindow and maxTimeDifference in vega specification)
   * @param legendInfo source of legend info for graph (e.g. sensor phenomenon)
   * @param isAnalytics isAnalytics true/false analytics/observations
   */
  static getGraphType(sensors, data, interval, legendInfo, isAnalytics): Graph {
    if (sensors == null) {
      return new EmptyGraph("No sensors selected.");

    }  else if (Array.isArray(sensors)) {
      if (sensors.length == 0) {
        return new EmptyGraph("No sensors selected.");
      } else if (sensors.length == 1) {
        return new SingleGraph(sensors[0], isAnalytics, data, legendInfo,interval);
      } else {
        return new MultiGraph(isAnalytics, data, legendInfo,interval);
      }

    } else {
      return new SingleGraph(sensors, isAnalytics, data, legendInfo, interval);
    }
  }


  /**
   * Displays the graph
   * @param spec vega specification
   * @param config vega configuration
   * @param element name of html element for graph display
   */
  static showGraph(spec, config, element) {
    const vega = require('vega');
    const vegaTooltip = require('vega-tooltip');
    const handler = new vegaTooltip.Handler();


    const view = new vega.View(vega.parse(spec, config))
      .tooltip(handler.call)
      .initialize(element)
      .hover()
      .runAsync();
  }
}