ErsatzTV/ErsatzTV/Shared/EditExternalJsonFileDialog.razor

<MudDialog>
    <DialogContent>
        <MudContainer Class="mb-6">
            <MudText>
                Edit the playout's external json file
            </MudText>
        </MudContainer>
        <MudTextField Label="External Json File" @bind-Value="_externalJsonFile"/>
    </DialogContent>
    <DialogActions>
        <MudButton OnClick="@Cancel" ButtonType="ButtonType.Reset">Cancel</MudButton>
        <MudButton Color="Color.Primary" Variant="Variant.Filled" Disabled="@(string.IsNullOrWhiteSpace(_externalJsonFile))" OnClick="@Submit">
            Save Changes
        </MudButton>
    </DialogActions>
</MudDialog>

@code {
    [Parameter]
    public string ExternalJsonFile { get; set; }

    [CascadingParameter]
    IMudDialogInstance MudDialog { get; set; }

    private string _externalJsonFile;

    protected override void OnParametersSet() => _externalJsonFile = ExternalJsonFile;

    private void Submit() => MudDialog.Close(DialogResult.Ok(_externalJsonFile));

    private void Cancel() => MudDialog.Cancel();
}