dotvvm | Open source MVVM framework for Web Apps | DevOps library

DotVVM does not work this way, controls don't have any state and thus manipulating them in commands does not make much sense. Controls in DotVVM are just thin wrappers around the HTML that is sent to the client on the first request. Since no HTML is generated on commands, modifications of the controls don't propagate to the browser (except when you use Postback.Update property on the control)

You want to store the state in your view model and then data bind it to the control. I'm not sure what exactly you want to do so let's suppose you want to highlight a div in some cases. The markup (in dothtml file) could look like this:

The BootstrapColor enum should be treated as a presentation layer thing. You are right that it's not wise to use it in internal microservices or in lower layers of the application.

The DTO that comes from the lower layer should contain the information about what's going on, without caring about how it will be displayed to the user. I would expect an enum with values like Paid, Unpaid, Canceled etc., or alternatively set of bool flags - IsPaid, IsCanceled and so on.

In the presentation layer, you have two options:

1. Project the DTO to another DTO (either manually, or using AutoMapper for example) which will contain the BootstrapColor enum value.

2. Use expressions in DotVVM data-bindings to make the transform in the markup.

For simple cases, I would choose the second option.

The correct syntax for is this:

In DotVVM 2.3.0, we have added an overload ofReturnFile which allows to specify Content-Disposition header. If you set it to inline, it should display the document instead of downloading it.

Perhaps you won't call method DotvvmStartup.ConfigureServices. It is cause by "bug" in VS2017 extension template (v2.0.118.0 and below) and dotnet CLI template (dotvvm.templates.2.0.3).

Please check Startup.ConfigureServices.

If you are in the viewmodel, you can just call Context.RedirectToRoute("YourRoute", new { Param1 = something }).

If you want to redirect from a different place, the easiest way is to create INavigationService interface and implement it to call the method on IDotvvmRequestContext (which is already registered in the ASP.NET Core dependency injection container):

Value bindings don't work in script elements - they are translated to Knockout JS expressions (the HTML comments you have in the code snippet).

You have two options:

1. Use resource binding: {{resource: ChartLabels}} You need to do all the conversions so it will produce a valid JavaScript expression - it just renders a string in the output HTML.

2. You may use JavaScript to get the values directly from the viewmodel:

DotVVM does not assign to the property usning the setter, is sets the underlying property store in DotvvmBindableObject instead. It's very simmilar what WPF does with their DependencyProperty, it's needed to represent the data bindings. You can actually completely omit the C# property declaration, declaring the field TextProperty and calling the DotvvmProperty.Register is enough to declare a property for dotvvm.

Other "problem" is that the controls do not store any data, everything has to be persisted in the view model. You can only use the control properties to data-bind a view model property. I think we are running here into a XY problem, I can only tell why your code does not work, but I have no idea what are actually trying to do...

Anyway, if you just want to "bind" your control to a view model property, have a look at https://www.dotvvm.com/docs/tutorials/control-development-markup-controls-with-code/2.0. You can declare the property like that:

You bind Alert type to AlertType property which you set in viewmodel Init only. So when you change AlertComponent later, you didn't setup AlertType.

Or you can use a litle trick

It really depends on the type of the application you are trying to create. The fact is that you can build any application in any web technology. The difference is only in how difficult it would be.

Razor Pages are very easy to use and they are part of ASP.NET Core platform. They are using the MVVM pattern, but they are not helping with client interactivity. If you need to hide some form field based on some condition, you would need to do it in JavaScript.

I would use them for a simple company website, very simple admin sites with few pages and trivial forms, or for a public facing part of some eCommerce site. I would probably use also jQuery or other libraries to do the interactivity, animations and things like that.

DotVVM is an MVVM framework which helps especially with web applications with complicated UI: lots of complex forms with dozens of fields and interactivity (when you select an item in a combobox, another combobox will get new values, some fields will be pre-filled, a part of the form will disappear or change and so on). Modal dialogs, multi-step wizards, lots of grids with data, sorting, paging...

Because DotVVM handles many things for you and translates the data-bindings to JavaScript, you don't need to write the JS yourself. It doesn't mean that you should not learn it. It will help you a lot if you know it - you will be able to add even more interactivity, extend the framework when you need it and more. DotVVM lets you do quite a lot without knowing JS, but you will get much further if you know it.

Angular, React or other client-side frameworks are used widely today and many websites and applications are built in that. They are more universal than DotVVM, which aims primarily at the business app segment and requires .NET on the server (because it is not only the client-side library).

Using Angular or React requires the knowledge of JavaScript, and not only that. You will need to know Node.js and the related tooling, like npm. You will need to exchange data with the server, so you will need to build probably a REST API, use Swagger to generate the client-side proxy classes, and then you will probably need some other JS libraries with controls and things like that.

It is quite a lot of things to learn and if you are used to the comfort of Visual Studio, like the IntelliSense or the debugger, you will miss these features for sure.

And finally, you don't need to stick to one technology. You can combine Razor Pages with DotVVM for example. You can make the admin dashboard in DotVVM and the public part of the website in Razor Pages.