constructor()

in Hands-on lab/lab-files/starter-project/NorthwindMVC/wwwroot/lib/Chart.js/chart.js [6553:6608]

• 56 lines of code
• 10 McCabe index (conditional complexity)

  constructor(item, userConfig) {
    const me = this;
    const config = this.config = new Config(userConfig);
    const initialCanvas = getCanvas(item);
    const existingChart = getChart(initialCanvas);
    if (existingChart) {
      throw new Error(
        'Canvas is already in use. Chart with ID \'' + existingChart.id + '\'' +
				' must be destroyed before the canvas can be reused.'
      );
    }
    const options = config.createResolver(config.chartOptionScopes(), me.getContext());
    this.platform = new (config.platform || _detectPlatform(initialCanvas))();
    const context = me.platform.acquireContext(initialCanvas, options.aspectRatio);
    const canvas = context && context.canvas;
    const height = canvas && canvas.height;
    const width = canvas && canvas.width;
    this.id = uid();
    this.ctx = context;
    this.canvas = canvas;
    this.width = width;
    this.height = height;
    this._options = options;
    this._aspectRatio = this.aspectRatio;
    this._layers = [];
    this._metasets = [];
    this._stacks = undefined;
    this.boxes = [];
    this.currentDevicePixelRatio = undefined;
    this.chartArea = undefined;
    this._active = [];
    this._lastEvent = undefined;
    this._listeners = {};
    this._responsiveListeners = undefined;
    this._sortedMetasets = [];
    this.scales = {};
    this.scale = undefined;
    this._plugins = new PluginService();
    this.$proxies = {};
    this._hiddenIndices = {};
    this.attached = false;
    this._animationsDisabled = undefined;
    this.$context = undefined;
    this._doResize = debounce(() => this.update('resize'), options.resizeDelay || 0);
    instances[me.id] = me;
    if (!context || !canvas) {
      console.error("Failed to create chart: can't acquire context from the given item");
      return;
    }
    animator.listen(me, 'complete', onAnimationsComplete);
    animator.listen(me, 'progress', onAnimationProgress);
    me._initialize();
    if (me.attached) {
      me.update();
    }
  }