JS不在txt中写入信息

时间:2019-11-24 15:31:03

标签: javascript

我是js新手。所以我安装了node.js。

我所拥有的:我有html文件,可在浏览器中打开地图。当用户右键单击时,它应该创建txt文件并在其中写入“学习如何写入文件”,但是没有。

<!DOCTYPE html>
<head>    
    <meta http-equiv="content-type" content="text/html; charset=UTF-8" />
    <script>
        L_NO_TOUCH = false;
        L_DISABLE_3D = false;
    </script>
    <script src="https://cdn.jsdelivr.net/npm/leaflet@1.5.1/dist/leaflet.js"></script>
    <script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/Leaflet.awesome-markers/2.0.2/leaflet.awesome-markers.js"></script>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/leaflet@1.5.1/dist/leaflet.css"/>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css"/>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap-theme.min.css"/>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.6.3/css/font-awesome.min.css"/>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/Leaflet.awesome-markers/2.0.2/leaflet.awesome-markers.css"/>
    <link rel="stylesheet" href="https://rawcdn.githack.com/python-visualization/folium/master/folium/templates/leaflet.awesome.rotate.css"/>
    <style>html, body {width: 100%;height: 100%;margin: 0;padding: 0;}</style>
    <style>#map {position:absolute;top:0;bottom:0;right:0;left:0;}</style>
        <meta name="viewport" content="width=device-width,
                initial-scale=1.0, maximum-scale=1.0, user-scalable=no" />
        <style>
            #map_fc81479c2a8c4f18ad55baf3c9ba4285 {
                position: relative;
                width: 100.0%;
                height: 100.0%;
                left: 0.0%;
                top: 0.0%;
            }
        </style> 

    <script src="https://requirejs.org/docs/release/2.3.6/minified/require.js"></script>
</head>

<body>    
    <div class="folium-map" id="map_fc81479c2a8c4f18ad55baf3c9ba4285" ></div>    
</body>

<script>    
    var map_fc81479c2a8c4f18ad55baf3c9ba4285 = L.map(
        "map_fc81479c2a8c4f18ad55baf3c9ba4285",
        {
        center: [55.02111, 73.40751],
        crs: L.CRS.EPSG3857,
        zoom: 13,
        zoomControl: true,
        preferCanvas: false,
        }
        );
        var tile_layer_216c8662dc00405dba72c81174fd5845 = L.tileLayer(
            "https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png",
            {"attribution": "Data by \u0026copy; \u003ca href=\"http://openstreetmap.org\"\u003eOpenStreetMap\u003c/a\u003e, under \u003ca href=\"http://www.openstreetmap.org/copyright\"\u003eODbL\u003c/a\u003e.", "detectRetina": false, "maxNativeZoom": 18, "maxZoom": 18, "minZoom": 0, "noWrap": false, "opacity": 1, "subdomains": "abc", "tms": false}
            ).addTo(map_fc81479c2a8c4f18ad55baf3c9ba4285);


    var lat, lng;

    map_fc81479c2a8c4f18ad55baf3c9ba4285.addEventListener('mousemove', function(ev) {
        lat = ev.latlng.lat;
        lng = ev.latlng.lng;
    });

    document.getElementById("map_fc81479c2a8c4f18ad55baf3c9ba4285").addEventListener("contextmenu", function (event) {
    // Prevent the browser's context menu from appearing
    event.preventDefault();
    alert(lat + ' - ' + lng);
    return false; // To disable default popup.
});

// Trying to save to text file
// !!!
// !!!
// !!!
// does not work : 

const fs = require('fs') 

let data = "Learning how to write in a file."

fs.writeFile('Output.txt', data, (err) => {
    if (err) throw err; 
}) 

</script>

,如果我在浏览器中打开控制台,则会显示: enter image description here

  

85 raw:const fs = require('fs')

但是,如果我运行的代码应该在一个单独的js文件中创建一个文件,那么它会很好。

当用户右键单击地图时,我应该怎么做才能创建文件?

编辑1:

已添加脚本,但仍然无法正常工作

<script src="https://requirejs.org/docs/release/2.3.6/minified/require.js"> 
</script>

enter image description here

1 个答案:

答案 0 :(得分:0)

JavaScript是一种基于浏览器的网络语言。您无法在浏览器环境之外执行任何操作。浏览器不会访问文件系统和其他模块。

这是 Node js 解决的问题。如果您想使用javascript访问文件系统,建议您使用Node作为后端创建一个快速的Web应用程序,使您可以写入文件等。

免费使用Google 节点 Express ,您将在线获得许多示例。

希望这对您有帮助...