Cfrgtkky

Basically User enters page, generates report and decides whether it should be saved or not.

If yes, then I have to save this html as static html file.

It'd be really nice if that was something like:

public IActionResult GetReport()

{

    (...)

    string html = View(model).ToString();

    save_to_database(html);

    return View(model);

}

But, the only solution that I managed to find is putting button on that page
which executes JavaScript like this one:

var html = new XMLSerializer().serializeToString(document); 



sendHTMLViaAPI(html);

and sending that html to API via post.

So, I'm curious whether there are C#-ish ways to do it? in Controller's method.

Also: Is that potentially dangerous? E.g. session things can be saved in that html file or user can send content of non-HTML file via API...

If I understand you meant correctly, this solution may be what you're looking for:

[HttpPost]

public IActionResult GetHTML()

{

    var model = new ModelClass() { Content = "Hi!" };



    // or

    // return PartialView("GetHTML", model);

    return PartialView(nameof(GetHTML), model);

}

In the file GetHTML.cshtml:

@model ModelClass 

<div>

    Content: @Model.Content

</div>

In the clientside, when user wants to get the HTML as string, you can try to use jquery to get it:

$.post('/home/gethtml').done(function (html) {

    // html is a string here..



    // <div>

    //     Content: Hi!

    // </div>



    $('body').append(html);

});

Or creating your custom service:

ViewRender.cs

using Microsoft.AspNetCore.Http;

using Microsoft.AspNetCore.Mvc;

using Microsoft.AspNetCore.Mvc.Abstractions;

using Microsoft.AspNetCore.Mvc.ModelBinding;

using Microsoft.AspNetCore.Mvc.Razor;

using Microsoft.AspNetCore.Mvc.Rendering;

using Microsoft.AspNetCore.Mvc.ViewFeatures;

using Microsoft.AspNetCore.Routing;

using System;

using System.IO;



public class ViewRender : IViewRender

{

    private IRazorViewEngine _viewEngine;



    private ITempDataProvider _tempDataProvider;



    private IServiceProvider _serviceProvider;



    public ViewRender(

        IRazorViewEngine viewEngine, 

        ITempDataProvider tempDataProvider, 

        IServiceProvider serviceProvider)

    {

        _viewEngine = viewEngine;

        _tempDataProvider = tempDataProvider;

        _serviceProvider = serviceProvider;

    }



    public string Render(string name)

    {

        var actionContext = GetActionContext();



        var viewEngineResult = _viewEngine.FindView(actionContext, name, false);



        if (!viewEngineResult.Success)

        {

            throw new InvalidOperationException(string.Format("Couldn't find view '{0}'", name));

        }



        var view = viewEngineResult.View;



        using (var output = new StringWriter())

        {

            var viewContext = new ViewContext(

                actionContext, 

                view, 

                new ViewDataDictionary<string>(

                    metadataProvider: new EmptyModelMetadataProvider(), 

                    modelState: new ModelStateDictionary())

                {

                    Model = null

                }, 

                new TempDataDictionary(actionContext.HttpContext, _tempDataProvider), 

                output, 

                new HtmlHelperOptions());



            view.RenderAsync(viewContext).GetAwaiter().GetResult();



            return output.ToString();

        }

    }



    public string Render<TModel>(string name, TModel model)

    {

        var actionContext = GetActionContext();



        var viewEngineResult = _viewEngine.FindView(actionContext, name, false);



        if (!viewEngineResult.Success)

        {

            throw new InvalidOperationException(string.Format("Couldn't find view '{0}'", name));

        }



        var view = viewEngineResult.View;



        using (var output = new StringWriter())

        {

            var viewContext = new ViewContext(

                actionContext, 

                view, 

                new ViewDataDictionary<TModel>(

                    metadataProvider: new EmptyModelMetadataProvider(), 

                    modelState: new ModelStateDictionary())

                {

                    Model = model

                }, 

                new TempDataDictionary(actionContext.HttpContext, _tempDataProvider), 

                output,                     

                new HtmlHelperOptions());



            view.RenderAsync(viewContext).GetAwaiter().GetResult();



            return output.ToString();

        }

    }



    private ActionContext GetActionContext()

    {

        var httpContext = new DefaultHttpContext();



        httpContext.RequestServices = _serviceProvider;



        return new ActionContext(httpContext, new RouteData(), new ActionDescriptor());

    }

}

IViewRender.cs:

public interface IViewRender

{

    string Render(string name);



    string Render<TModel>(string name, TModel model);

}

Startup.cs:

services.AddTransient<IViewRender, ViewRender>();

Usage:

public class HomeController : Controller

{

    private readonly IViewRender _viewRender { get; set; }



    public HomeController(IViewRender viewRender)

    {

        _viewRender = viewRender;

    }



    public IActionResult GetHTML()

    {

        string htmlWithoutModel = _viewRender.Render("Home/GetHTML");



        var model = new ModelClass() { Content = "Hi!" };



        string htmlWithModel = _viewRender.Render<ModelClass>("Home/GetHTML", model);



        //...

    }

}