Utilize a JavaScript <script> tag on a single razor page

Question

Utilize a JavaScript <script> tag on a single razor page

Is it possible to use a specific .js file just inside a particular razor page when using blazor and .Net 5?

Just to provide some context, I created a simple script named MyJavaScript.js:

function myfunction()
  {
    alert("Hello");
  }

I then added this script to _host.cshtml:

<script src="/MyJavaScript.js"></script>

Currently, whenever I navigate to any razor page in my web app (e.g., localhost:1212, localhost:1212/counter), the .js file is loaded on the first visit and accessible across all razor pages. However, I am interested in restricting the usage of this .js file to just one specific razor page (mypage.razor). Is there a way to achieve this?

In simpler terms, I want only localhost:1212/mypage to display the alert and have access to myfunction, rather than making it available across all razor pages. Where should I place the MyJavaScript.js file to accomplish this?

Update 1: It seems that placing the <script></script> tag inside a component is not supported.

https://i.sstatic.net/lcfAj.jpg

javascript blazor-server-side

Answer 1

Answer №1

Based on your screenshot, it seems like you're close to the solution - all you need to do is import the JavaScript module using IJSRuntime and then call the function as usual with IJSObjectReference. Just ensure that your JavaScript file function includes the export keyword.

The code snippet provided above gives a clear example for .NET 5:

// wwwroot/scripts.js
export function showPrompt(message) {
  return prompt(message, 'Type anything here');
}

@page "/call-js-example-6"
@implements IAsyncDisposable
@inject IJSRuntime JS

<h1>Call JS Example 6</h1>

<p>
    <button @onclick="TriggerPrompt">Invoke browser window prompt</button>
</p>

<p>
    @result
</p>

@code {
    private IJSObjectReference module;
    private string result;

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

    private async Task TriggerPrompt()
    {
        result = await Prompt("Enter some text");
    }

    public async ValueTask<string> Prompt(string message)
    {
        return await module.InvokeAsync<string>("showPrompt", message);
    }

    async ValueTask IAsyncDisposable.DisposeAsync()
    {
        if (module is not null)
        {
            await module.DisposeAsync();
        }
    }
}

Answer 2

Based on your screenshot, it seems like you're close to the solution - all you need to do is import the JavaScript module using IJSRuntime and then call the function as usual with IJSObjectReference. Just ensure that your JavaScript file function includes the export keyword.

The code snippet provided above gives a clear example for .NET 5:

// wwwroot/scripts.js
export function showPrompt(message) {
  return prompt(message, 'Type anything here');
}

@page "/call-js-example-6"
@implements IAsyncDisposable
@inject IJSRuntime JS

<h1>Call JS Example 6</h1>

<p>
    <button @onclick="TriggerPrompt">Invoke browser window prompt</button>
</p>

<p>
    @result
</p>

@code {
    private IJSObjectReference module;
    private string result;

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

    private async Task TriggerPrompt()
    {
        result = await Prompt("Enter some text");
    }

    public async ValueTask<string> Prompt(string message)
    {
        return await module.InvokeAsync<string>("showPrompt", message);
    }

    async ValueTask IAsyncDisposable.DisposeAsync()
    {
        if (module is not null)
        {
            await module.DisposeAsync();
        }
    }
}

Utilize a JavaScript <script> tag on a single razor page

Answer №1

Similar questions

Why aren't my Post Variables being passed through my jQuery Ajax Request?

When it comes to TypeScript, one can always rely on either event.target or event

alerts and malfunctions encountered while using Karma and Chrome

Incorporating an external JavaScript file into an AngularJS project

What is the process for attaching an on-click event listener by utilizing an argument that is passed to a function in JavaScript?

Running a loop to animate in a callback function

Ways to verify HTML code consistency for mobile phone web applications on various devices

What is the best way to manage data in a single-page application and retrieve it after the page has been refreshed?

Angular allows you to set specific conditions for when a failed HTTP request should be retried, and you can also specify the number of attempts that should be

Use JSON to initiate opening a new tab in JavaScript code

Capturing and Receiving Voice Audio in DiscordJSv14

What could be the reason for XMLHttpRequest to freeze with no error until it reaches the default browser timeout limit

Guide on utilizing direction.set within threejs for Vector3 types

There seems to be an issue with the calculation in my React app as it only displays the correct result after the second symbol

Discover the powerful combination of Sweet Alert 2 JS library and seamless Interop in Blazor Server

Listening to multiple events in AngularJS using `$scope.$on`

Executing an action using onclick in JavaScript within a Ruby on Rails environment

Sequelize: When attempting to use .get({plain: true})) method, an error is returned indicating that .get is

What is the process for turning off a TypeScript rule for a single line of code?

Keep the active button state when it is clicked in React JS within a functional component