使用Typescript和Webpack的Fabric.js：Canvas不是构造函数 [英] Fabric.js with Typescript and Webpack: Canvas is not a constructor

问题描述

我正在尝试将除了Typescript和Webpack的fabric.js放在Laravel 5.4应用程序中的一些其他模块中，这些模块在浏览器中运行良好。 @ types / fabric ist已安装且Typescript行为正确。打字稿和Webpack的新手我尝试了一些变种没有成功。

I'm trying to use fabric.js with Typescript and Webpack aside some other modules in a Laravel 5.4 application that work fine in the browser. @types/fabric ist installed and Typescript behaves correct. New to Typescript as well as Webpack i tried some variants with no success.

问题

result.js:198 Uncaught TypeError: __WEBPACK_IMPORTED_MODULE_1_fabric___default.a.Canvas is not a constructor

变体A

code.ts

import fabric from "fabric";
const canvas = new fabric.Canvas('my-canvas');

result.js

var canvas = new __WEBPACK_IMPORTED_MODULE_1_fabric__default.a.Canvas('my-canvas');

WEBPACK_IMPORTED_MODULE_1_fabric__default需要WEBPACK_IMPORTED_MODULE_1_fabric，这是一个以面料为关键字的对象。

WEBPACK_IMPORTED_MODULE_1_fabric__default requires WEBPACK_IMPORTED_MODULE_1_fabric which is an object with fabric as key.

const canvas = new fabric.fabric.Canvas('my-canvas');

适用于Webpack，但不符合类型检查。

would be working for Webpack but is not conform to type inspections.

变体B

code.ts

import * as fabric from "fabric";
const canvas = new fabric.Canvas('my-canvas');

result.js

var canvas = new __WEBPACK_IMPORTED_MODULE_1_fabric__["Canvas"]('my-canvas');

WEBPACK_IMPORTED_MODULE_1_fabric包含一个带有fabric作为关键字的对象，因此情况与变体A类似。

WEBPACK_IMPORTED_MODULE_1_fabric contains an object with fabric as key so that the situation is like with variant A.

变体C

code.ts

import {Canvas} from "fabric";
const canvas = new Canvas('my-canvas');

result.js

var canvas = new __WEBPACK_IMPORTED_MODULE_1_fabric__["Canvas"]('my-canvas');

最后它与变体B相同。

摘录webpack.mix.js

   .webpackConfig({
    module: {
        rules: [
            {
                test: /\.js$/,
                loader: 'babel-loader',
                include: [
                    path.resolve('app/public/js'),
                    path.resolve('node_modules/countable')
                ],
            },
            {
                test: /\.vue$/,
                loader: 'vue-loader',
                exclude: [
                    path.resolve('resources/assets/ts/components')
                ],
                options: {
                    loaders: {
                        'scss': 'vue-style-loader!css-loader!sass-loader',
                        'sass': 'vue-style-loader!css-loader!sass-loader?indentedSyntax',
                    }
                }
            },
            {
                test: /\.tsx?$/,
                loader: 'ts-loader',
                exclude: /node_modules/,
                options: {
                    appendTsSuffixTo: [/\.vue$/],
                }
            },
        ]
    },
    plugins: [
        new webpack.ProvidePlugin({
            '_': 'lodash',
            '$': 'jquery',
            'jQuery': 'jquery',
            'window.jQuery': 'jquery', 
        }),
        new LiveReloadPlugin()
    ],
    resolve: {
        extensions: ['.js', '.ts', '.vue', '.jsx', '.tsx', '.vuex'],
        alias: {
            'vue$': 'vue/dist/vue.esm.js',
        }
    }

问题似乎是在Webpack和/或babel-loader中没有考虑结构名称空间。

The problem seem to be in Webpack and/or the babel-loader doesn't take the fabric namepace into account.

所以问题是是否有任何方法告诉Webpack处理这个导入以某种方式它直接引用fabric（或那种导入的库）或者以一种Webpack很高兴的方式将它导入到Typescript中？

So the question is if there is any method to tell Webpack to handle this import in a way that it directly references fabric (or an imported library of that kind) or to import it into Typescript in a way that also Webpack is happy?

推荐答案

这对我有用：

import 'fabric' ;
declare let fabric: any;

var c = new fabric.Canvas('myCanvas') ;

我在TypeScript 2.5.3和webpack 3.5.1上使用@ types / fabric 1.5.26

I'm using @types/fabric 1.5.26 on TypeScript 2.5.3 and webpack 3.5.1

这篇关于使用Typescript和Webpack的Fabric.js：Canvas不是构造函数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！