Simple Cryptocurrency App With Blazor Server Including Excel Export

For some reason, I started to like developing with Blazor Server, mainly because the rapidity and simplicity of development. I tend to use some free component libraries to speed up development. I still want to mention that all my experience with Blazor Server is only on tutorial/experimental level.

This is just an application to learn Blazor Server, and familiarize with Cryptocurrencies, it has no other purpose.

Prerequisites for this app:

• basic Blazor Server (See my previous tutorials)
• install Radzen Components in your app see https://blazor.radzen.com/get-started
• using the C# wrapper for CoinPaprika Api (to get cryptocurrency info) https://github.com/MSiccDev/CoinpaprikaAPI

Code repository: https://github.com/zoltanhalasz/BlazorCoins

Application is live under: https://blazorcoins.zoltanhalasz.net/

The app works the following way:

1. the route /cointable will show the top 100 crypto currencies, using the API
2. clicking the detail per each currency, the route /coinhistory will show a chart and historical data for selected currency
3. the route /coingrid will show exactly the same info as 1) only in a Radzen Grid

Bonus:

The app has export excel capabilities, which can be achieved doing the following:

create wwwroot/js/DownloadExcel.js

function saveAsExcel(fileName, byteContent) {
    var link = document.createElement('a');
    link.download = fileName;
    console.log(fileName);
    link.href = 'data:application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;base64,' + byteContent;
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
}

include the file reference at the bottom of _Host.cshtml, just below the other scripts

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

install EPPlus, latest, via Nuget Packages

in page /cointable (or where you need to export from excel), insert the markup for a button

 <button class="btn btn-primary" @onclick="GenerateExcel">Download</button>

include the following in the top of the page you want to use Excel Export:

@inject IJSRuntime iJSRuntime;

Write the handlers for GenerateExcel, in the code section of the page where you have the list that you need to export in Excel

private async Task DownloadExcel(IJSRuntime myJSRuntime)
{
        byte[] file;
        if (coinList == null) return;
        ExcelPackage.LicenseContext = LicenseContext.NonCommercial;
        using (var package = new ExcelPackage())
        {
            var worksheet = package.Workbook.Worksheets.Add("Sheet1");
            worksheet.Cells.LoadFromCollection(coinList, true);
            package.Save();
            file = package.GetAsByteArray();
        }

        await myJSRuntime.InvokeAsync<List<CoinInfo>>("saveAsExcel", "CoinList.xlsx", Convert.ToBase64String(file));
    }

    private async Task GenerateExcel()
    {
        await DownloadExcel(iJSRuntime);
    }