“未捕获的语法错误:无法在模块外使用导入语句"；导入 ECMAScript 6 时 [英] "Uncaught SyntaxError: Cannot use import statement outside a module" when importing ECMAScript 6

问题描述

我正在使用 ArcGIS JSAPI 4.12 并希望使用 Spatial Illusions 在地图上绘制军事符号.

I'm using ArcGIS JSAPI 4.12 and wish to use Spatial Illusions to draw military symbols on a map.

当我将 milsymbol.js 添加到脚本中时，控制台返回错误

When I add milsymbol.js to the script, the console returns error

未捕获的语法错误:不能在模块外使用导入语句`

Uncaught SyntaxError: Cannot use import statement outside a module`

所以我将 type="module" 添加到脚本中，然后它返回

so I add type="module" to the script, and then it returns

未捕获的引用错误:ms 未定义

Uncaught ReferenceError: ms is not defined

这是我的代码:

<link rel="stylesheet" href="https://js.arcgis.com/4.12/esri/css/main.css">
<script src="https://js.arcgis.com/4.12/"></script>
<script type="module" src="milsymbol-2.0.0/src/milsymbol.js"></script>

<script>
    require([
        "esri/Map",
        "esri/views/MapView",
        "esri/layers/MapImageLayer",
        "esri/layers/FeatureLayer"
    ], function (Map, MapView, MapImageLayer, FeatureLayer) {

        var symbol = new ms.Symbol("SFG-UCI----D", { size: 30 }).asCanvas(3);
        var map = new Map({
            basemap: "topo-vector"
        });

        var view = new MapView({
            container: "viewDiv",
            map: map,
            center: [121, 23],
            zoom: 7
        });
    });
</script>

所以，不管我加不加type="module"，总会有错误.但是，在Spatial Illusions的官方文档中，脚本中并没有任何type="module".我现在真的很困惑.他们如何在不添加类型的情况下使其工作?

So, whether I add type="module" or not, there are always errors. However, in the official document of Spatial Illusions, there isn't any type="module" in the script. I'm now really confused. How do they manage to get it work without adding the type?

import { ms } from "./ms.js";

import Symbol from "./ms/symbol.js";
ms.Symbol = Symbol;

export { ms };

推荐答案

我收到这个错误是因为我忘记了脚本标签中的 type=module":

I got this error because I forgot the type="module" inside the script tag:

<script type="module" src="milsymbol-2.0.0/src/milsymbol.js"></script>

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