btcpayserver/BTCPayServer/Blazor/PosLoginCode.razor

@using Microsoft.AspNetCore.Http

@inject IHttpContextAccessor HttpContextAccessor

@if (Users?.Any() is true)
{
    <div @attributes="Attrs" class="@CssClass">
        <label for="SignedInUser" class="form-label" text-translate="true">Signed in user</label>
        <select id="SignedInUser" class="form-select" value="@_userId" @onchange="@(e => _userId = e.Value?.ToString())">
            <option value="" text-translate="true">None, just open the URL</option>
            @foreach (var u in Users)
            {
                <option value="@u.Key">@u.Value</option>
            }
        </select>
    </div>
}

@if (string.IsNullOrEmpty(_userId))
{
    <QrCode Data="@PosUrl" />
}
else
{
    <UserLoginCode UserId="@_userId" RedirectUrl="@PosPath" />
}

@code {
    [Parameter, EditorRequired]
    public string PosPath { get; set; }

    [Parameter]
    public Dictionary<string,string> Users { get; set; }

    [Parameter(CaptureUnmatchedValues = true)]
    public Dictionary<string, object> Attrs { get; set; }

    private string _userId;
    private string PosUrl => Request.GetAbsoluteRoot() + PosPath;
    private HttpRequest Request => HttpContextAccessor.HttpContext?.Request;
    private string CssClass => $"form-group {(Attrs?.ContainsKey("class") is true ? Attrs["class"] : "")}".Trim();
}