migrating from canvas-prebuilt which was deprecated to canvas 2.6.1 and refactoring code

README.md

@@ -7,7 +7,7 @@ OS X | `brew install pkg-config cairo pango libpng jpeg giflib`
 Ubuntu | `sudo apt-get install libcairo2-dev libjpeg8-dev libpango1.0-dev libgif-dev build-essential g++`
 Fedora | `sudo yum install cairo cairo-devel cairomm-devel libjpeg-turbo-devel pango pango-devel pangomm pangomm-devel giflib-devel`
 Solaris | `pkgin install cairo pango pkg-config xproto renderproto kbproto xextproto`
-Windows | [Instructions on our wiki](https://github.com/Automattic/node-canvas/wiki/Installation---Windows)
+Windows | `npm i` or `npm install` (canvas will be installed automatically)
 
 ```
 npm install node-echarts
@@ -37,4 +37,4 @@ node_echarts(config)
 |height|Number|500|Image height|
 |option|Object|{}|Echarts Options|
 |path|String|-|Path is filepath of the image which will be created. If the path is empty, return buffer.|
-|enableAutoDispose|Boolean|true|Enable auto-dispose echarts after the image is created.|
+|enableAutoDispose|Boolean|true|Enable auto-dispose echarts after the image is created.|

index.js

@@ -1,8 +1,69 @@
 var echarts = require("echarts");
-var Canvas = require("canvas-prebuilt");
+var { createCanvas } = require("canvas");
 var fs = require('fs');
 var path = require('path');
 
+/**
+ * default echart option in case the client doesn't define
+ */
+function getDefaultOption() {
+ return {
+ title: {
+ text: 'test',
+ },
+ tooltip: {},
+ legend: {
+ data: ['test'],
+ },
+ xAxis: {
+ data: ["a", "b", "c", "d", "f", "g"],
+ },
+ yAxis: {},
+ series: [{
+ name: 'test',
+ type: 'bar',
+ data: [5, 20, 36, 10, 10, 20],
+ }]
+ };
+}
+
+/**
+ * default config for the option, in case the client doesn't
+ * define it.
+ * 
+ * @param {*} option echart option
+ */
+function getDefaultConfig(option) {
+ return {
+ width: 500,
+ height: 500,
+ option,
+ enableAutoDispose: true,
+ }
+}
+
+/**
+ * saves the chart passed in the provided path
+ * @param {*} chart chart in which thedom will be retrieved and saved
+ * as an image
+ * @param {*} path directory to the image that will be saved
+ */
+function saveChart(chart, path) {
+ try {
+ fs.writeFileSync(path, chart.getDom().toBuffer());
+ console.log("Created image:" + path)
+ } catch (err) {
+ console.error("Error: write file failed: " + err.message)
+ }
+}
+
+/**
+ * retrieves the buffer of the chart
+ * @param {*} chart chart in which the buffer will be retrieved
+ */
+function getBuffer(chart) {
+ return chart.getDom().toBuffer();
+}
 
 /**
  * @param config = {
@@ -12,72 +73,57 @@ var path = require('path');
  //If the path is not set, return the Buffer of image.
  path: '', // Path is filepath of the image which will be created.
  }
-
  *
  */
 module.exports = function (config) {
- if (config.canvas) {
- Canvas = config.canvas;
- }
 
- var ctx = new Canvas(128, 128);
+ const createdCanvas = createCanvas(128, 128);
+ const ctx = createdCanvas.getContext('2d');
+
  if (config.font) {
  ctx.font = config.font;
  }
 
  echarts.setCanvasCreator(function () {
- return ctx;
+ return createdCanvas;
  });
 
- var chart, option = {
- title: {
- text: 'test'
- },
- tooltip: {},
- legend: {
- data: ['test']
- },
- xAxis: {
- data: ["a", "b", "c", "d", "f", "g"]
- },
- yAxis: {},
- series: [{
- name: 'test',
- type: 'bar',
- data: [5, 20, 36, 10, 10, 20]
- }]
- };
-
- let defaultConfig = {
- width: 500,
- height: 500,
- option,
- enableAutoDispose: true
- }
+ const option = getDefaultOption();
+ const defaultConfig = getDefaultConfig(option);
 
- config = Object.assign({}, defaultConfig, config)
+ config = Object.assign({}, defaultConfig, config);
 
  config.option.animation = false;
- chart = echarts.init(new Canvas(parseInt(config.width, 10), parseInt(config.height, 10)));
+
+ const chart = echarts.init(
+ createCanvas(
+ parseInt(config.width, 10),
+ parseInt(config.height, 10),
+ ),
+ );
+
  chart.setOption(config.option);
- if (config.path) {
- try {
- fs.writeFileSync(config.path, chart.getDom().toBuffer());
- if(config.enableAutoDispose){
- chart.dispose();
- }
- console.log("Create Img:" + config.path)
- } catch (err) {
- console.error("Error: Write File failed" + err.message)
+
+ try {
+ /**
+ * if specified the path, the chart will be saved into it
+ */
+ if (config.path) {
+ saveChart(chart, config.path);
+ return;
  }
-
- } else {
- var buffer = chart.getDom().toBuffer();
- try{
- if(config.enableAutoDispose){
+
+ /**
+ * if not, the buffer will be returned
+ */
+ return getBuffer(chart);
+ } finally {
+
+ /**
+ * finally, dispose the chart if client defined so
+ */
+ if (config.enableAutoDispose) {
  chart.dispose();
- }
- }catch(e){}
- return buffer;
+ }
  }
 }

package.json

@@ -22,7 +22,7 @@
  },
  "homepage": "https://github.com/suxiaoxin/node-echarts#readme",
  "dependencies": {
- "canvas-prebuilt": "^1.6.5-prerelease.1",
+ "canvas": "^2.6.1",
  "echarts": "^4.0.3"
  },
  "devDependencies": {