Add chart abstract class

src/ts/chart.ts

+import * as d3 from 'd3';
+import { ChartConfiguration } from './chartConfiguration';
+
+export abstract class Chart {
+    protected config: {
+        parentSVGElement: string;
+        containerWidth: number;
+        containerHeight: number;
+        margin: { top: number; right: number; bottom: number; left: number; };
+    };
+    protected data: any[];
+    protected width: number;
+    protected height: number;
+    protected svg: d3.Selection<d3.BaseType, unknown, HTMLElement, any>;
+    protected chart: any;
+
+
+
+    /**
+     * Class constructor with basic chart configuration
+     */
+    constructor(_config: ChartConfiguration, _data: any[]) {
+
+        const vis = this;
+
+        // Configuration object with defaults
+        const { width, height } = _config.containerSize || vis.getDefaultContainerSize();
+        vis.config = {
+            parentSVGElement: _config.parentSVGElement,
+            containerWidth: width,
+            containerHeight: height,
+            margin: _config.margin || vis.getDefaultMargins()
+        };
+        vis.data = _data;
+        vis.initChart();
+    }
+
+    /**
+     * Returns default margin values.
+     */
+    protected abstract getDefaultMargins(): { top: number; right: number; bottom: number; left: number };
+
+    /**
+     * Returns default container size (width and height).
+     */
+    protected abstract getDefaultContainerSize(): { width: number; height: number };
+
+    /**
+     * Initialize chart element.
+     */
+    private initChart() {
+        const vis = this;
+
+        // Calculate inner chart size.
+        vis.width = vis.config.containerWidth - vis.config.margin.left - vis.config.margin.right;
+        vis.height = vis.config.containerHeight - vis.config.margin.top - vis.config.margin.bottom;
+
+        // Define size of SVG drawing area
+        vis.svg = d3.select(vis.config.parentSVGElement)
+            .attr('width', vis.config.containerWidth)
+            .attr('height', vis.config.containerHeight);
+
+        // Append group element that will contain our actual chart 
+        // and position it according to the given margin config
+        vis.chart = vis.svg.append('g')
+            .attr('transform', `translate(${vis.config.margin.left},${vis.config.margin.top})`);
+    }
+
+    /**
+     * Initialize scales/axes and append static elements, such as axis titles.
+     */
+    protected abstract initVis(): void;
+    /**
+     * This function contains the D3 code for binding data to visual elements.
+     * We call this function every time the data or configurations change.
+     */
+    protected abstract renderVis(): void;
+    /**
+     * This function contains all the code to prepare the data before we render it.
+     */
+    public abstract updateVis(): void;
+
+}
\ No newline at end of file

src/ts/chartConfiguration.ts

+export class ChartConfiguration {
+    /**
+     * parentSVGElement
+     */
+    public parentSVGElement: string;
+    public containerSize?: { width: number; height: number };
+    public margin?: { top: number; right: number; bottom: number; left: number };
+
+    constructor(parentSVGElement: string,
+        containerSize?: { width: number; height: number },
+        margin?: { top: number; right: number; bottom: number; left: number }) {
+
+        this.parentSVGElement = parentSVGElement;
+        this.containerSize = containerSize;
+        this.margin = margin;
+    }
+}
\ No newline at end of file

tsconfig.json

@@ -17,6 +17,7 @@
     "noEmit": true,
     /* Linting */
     "strict": true,
+    "strictPropertyInitialization": false,
     "noUnusedLocals": true,
     "noUnusedParameters": true,
     "noFallthroughCasesInSwitch": true,