C
C#•5mo ago
Pyro2817

Using JavaScript with Blazor

I'm currently working on a project that interacts with Google Maps API. It is now mandatory to use Javascript Map API, since it's needed some map manipulation. I have been stuck trying to load the map in the web page without success since yesterday. I read a lot of guides a saw some videos but the outcome is always the same, he cannot find the file. Does anyone have any idea what it could be wrong? Using: .Net 8, Blazor WebAssembly 
warn: Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer[100]
      Unhandled exception rendering component: error loading dynamically imported module: http://localhost:5047/_content/RouteMancer/js/maps.js

      Microsoft.JSInterop.JSException: error loading dynamically imported module: http://localhost:5047/_content/RouteMancer/js/maps.js

         at Microsoft.JSInterop.JSRuntime.InvokeAsync[TValue](Int64 targetInstanceId, String identifier, Object[] args)
         at RouteMancer.Components.MapComponents.Map.OnAfterRenderAsync(Boolean firstRender) in Google-Maps-API/RouteMancer/Components/MapComponents/Map.razor:line 16
         at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)
fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
      Unhandled exception in circuit 'XrWoEMkJXcoALPayi7sJx8D2J1iqxyvxtEFhihpHly4'.
      Microsoft.JSInterop.JSException: error loading dynamically imported module: http://localhost:5047/_content/RouteMancer/js/maps.js

         at Microsoft.JSInterop.JSRuntime.InvokeAsync[TValue](Int64 targetInstanceId, String identifier, Object[] args)
         at RouteMancer.Components.MapComponents.Map.OnAfterRenderAsync(Boolean firstRender) in Google-Maps-API/RouteMancer/Components/MapComponents/Map.razor:line 16
         at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)
warn: Microsoft.AspNetCore.Components.Server.Circuits.RemoteRenderer[100]
      Unhandled exception rendering component: error loading dynamically imported module: http://localhost:5047/_content/RouteMancer/js/maps.js

      Microsoft.JSInterop.JSException: error loading dynamically imported module: http://localhost:5047/_content/RouteMancer/js/maps.js

         at Microsoft.JSInterop.JSRuntime.InvokeAsync[TValue](Int64 targetInstanceId, String identifier, Object[] args)
         at RouteMancer.Components.MapComponents.Map.OnAfterRenderAsync(Boolean firstRender) in Google-Maps-API/RouteMancer/Components/MapComponents/Map.razor:line 16
         at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)
fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
      Unhandled exception in circuit 'XrWoEMkJXcoALPayi7sJx8D2J1iqxyvxtEFhihpHly4'.
      Microsoft.JSInterop.JSException: error loading dynamically imported module: http://localhost:5047/_content/RouteMancer/js/maps.js

         at Microsoft.JSInterop.JSRuntime.InvokeAsync[TValue](Int64 targetInstanceId, String identifier, Object[] args)
         at RouteMancer.Components.MapComponents.Map.OnAfterRenderAsync(Boolean firstRender) in Google-Maps-API/RouteMancer/Components/MapComponents/Map.razor:line 16
         at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)
3 Replies
Pyro2817
Pyro2817OP•5mo ago
wwwroot/js/maps.js 
window.JSMaps = window.JSMaps || (function () {
    let initialized = false;
    const mapObjects = {};

    async function loadApiScript(key, version) {
        if (initialized) {
            return;
        }

        (g => { 
            var h, a, k, p = "The Google Maps JavaScript API", c = "google", l = "importLibrary", q = "__ib__", m = document, b = window; 
            b = b[c] || (b[c] = {}); 
            var d = b.maps || (b.maps = {}), r = new Set, e = new URLSearchParams, u = () => h || (h = new Promise(async (f, n) => { await (a = m.createElement("script"));
            e.set("libraries", [...r] + "");
            for (k in g) e.set(k.replace(/[A-Z]/g, t => "_" + t[0].toLowerCase()), g[k]);
            e.set("callback", c + ".maps." + q);
            a.src = `https://maps.${c}apis.com/maps/api/js?` + e;
            d[q] = f;
            a.onerror = () => h = n(Error(p + " could not load."));
            a.nonce = m.querySelector("script[nonce]")?.nonce || "";
            m.head.append(a) }));
            d[l] ? console.warn(p + " only loads once. Ignoring:", g) : d[l] = (f, ...n) => r.add(f) && u().then(() => d[l](f, ...n)) 
        })({
            key: key,
            v: version,
        });

        initialized = true;
    }

    async function initMap(elementId, mapOptions, markerOptions) {
        ...
    }

    return {
        loadApiScript,
        initMap
    };
})();
window.JSMaps = window.JSMaps || (function () {
    let initialized = false;
    const mapObjects = {};

    async function loadApiScript(key, version) {
        if (initialized) {
            return;
        }

        (g => { 
            var h, a, k, p = "The Google Maps JavaScript API", c = "google", l = "importLibrary", q = "__ib__", m = document, b = window; 
            b = b[c] || (b[c] = {}); 
            var d = b.maps || (b.maps = {}), r = new Set, e = new URLSearchParams, u = () => h || (h = new Promise(async (f, n) => { await (a = m.createElement("script"));
            e.set("libraries", [...r] + "");
            for (k in g) e.set(k.replace(/[A-Z]/g, t => "_" + t[0].toLowerCase()), g[k]);
            e.set("callback", c + ".maps." + q);
            a.src = `https://maps.${c}apis.com/maps/api/js?` + e;
            d[q] = f;
            a.onerror = () => h = n(Error(p + " could not load."));
            a.nonce = m.querySelector("script[nonce]")?.nonce || "";
            m.head.append(a) }));
            d[l] ? console.warn(p + " only loads once. Ignoring:", g) : d[l] = (f, ...n) => r.add(f) && u().then(() => d[l](f, ...n)) 
        })({
            key: key,
            v: version,
        });

        initialized = true;
    }

    async function initMap(elementId, mapOptions, markerOptions) {
        ...
    }

    return {
        loadApiScript,
        initMap
    };
})();
App.razor 
@using static RouteMancer.Components.Routes

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <base href="/" />
    <link rel="stylesheet" href="app.css" />
    <link rel="icon" type="image/png" href="favicon.png" />
    <HeadOutlet @rendermode="new InteractiveServerRenderMode(prerender: false)" />
</head>

<body class="bg-gray-300">
    <Routes @rendermode="new InteractiveServerRenderMode(prerender: false)" />
    <script src="./_content/RouteMancer/js/maps.js" defer></script>       <---------- the file
    <script src="_framework/blazor.web.js"></script>
</body>

</html>
@using static RouteMancer.Components.Routes

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <base href="/" />
    <link rel="stylesheet" href="app.css" />
    <link rel="icon" type="image/png" href="favicon.png" />
    <HeadOutlet @rendermode="new InteractiveServerRenderMode(prerender: false)" />
</head>

<body class="bg-gray-300">
    <Routes @rendermode="new InteractiveServerRenderMode(prerender: false)" />
    <script src="./_content/RouteMancer/js/maps.js" defer></script>       <---------- the file
    <script src="_framework/blazor.web.js"></script>
</body>

</html>
Map.razor 
@inherits ComponentBase
@inject IJSRuntime JS
@implements IAsyncDisposable

<div @ref=@mapElement style="width: 900px; height: 818px;"></div>

@code {
    private IJSObjectReference? module;
    private ElementReference mapElement;
    private bool apiLoaded = false;

    protected override async Task OnAfterRenderAsync(bool firstRender) {
        if (firstRender) {
            if (module is null) {
                string path = "./js/maps.js";
                module = await JS.InvokeAsync<IJSObjectReference>("import", path);
            }

            if (!apiLoaded) {
                await module.InvokeVoidAsync("JSMaps.loadApiScript", Environment.GetEnvironmentVariable("MAPS_JS_MAP_API_KEY"));
                apiLoaded = true;
            }

            var mapOptions = new {...};
            var markerOptions = new {...};

            await module.InvokeVoidAsync("JSMaps.initMap", mapElement, mapOptions, markerOptions);
        }
    }

    public async ValueTask DisposeAsync() {
        if (module is not null) {
            await module.DisposeAsync();
        }
    }
}
@inherits ComponentBase
@inject IJSRuntime JS
@implements IAsyncDisposable

<div @ref=@mapElement style="width: 900px; height: 818px;"></div>

@code {
    private IJSObjectReference? module;
    private ElementReference mapElement;
    private bool apiLoaded = false;

    protected override async Task OnAfterRenderAsync(bool firstRender) {
        if (firstRender) {
            if (module is null) {
                string path = "./js/maps.js";
                module = await JS.InvokeAsync<IJSObjectReference>("import", path);
            }

            if (!apiLoaded) {
                await module.InvokeVoidAsync("JSMaps.loadApiScript", Environment.GetEnvironmentVariable("MAPS_JS_MAP_API_KEY"));
                apiLoaded = true;
            }

            var mapOptions = new {...};
            var markerOptions = new {...};

            await module.InvokeVoidAsync("JSMaps.initMap", mapElement, mapOptions, markerOptions);
        }
    }

    public async ValueTask DisposeAsync() {
        if (module is not null) {
            await module.DisposeAsync();
        }
    }
}
The Fog from Human Resources
The Fog from Human Resources•5mo ago
Iirc Blazor Was fully NoJS unless you did some weird workarounds Ran into the same issue a huge while back
Pyro2817
Pyro2817OP•5mo ago
I would prefer not to deal with JavaScript, but there's no way to use the api without it :waaaaaaaaaahhhhhh:
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