Save a Rendered Razor View as HTML string

Question

Is it possible, once a Razor View has been rendered in the browser, that the HTML and the contents of the mark up (images, tables, data etc.) can be saved as a string or other type?

I want to be able to generate the Razor View for the customer to check everything is ok in the output, then I want them to click a button that saves all of the HTML (Without all of the razor markup etc.).

How do you pass the HTML back to an Action , if it has to be processed pre-rendering, then how can this also be done.

I can then use this to generate PDF's and also save time on processing, as I will save the string in a database.

BTW, this is not a partial view nor will it use partial views, also I know there are still some things to fix in the Razor View, I am more interested in the saving the HTML at this point.

TIA

HTML Pre rendering HTML Post Rendering

Answer 1

You can use Middleware to obtain a copy of the HTML that is being sent to the browser. Create a class named ResponseToString with the following content:

public class ResponseToStringMidleware
{
    RequestDelegate _next;

    public ResponseToStringMidleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task Invoke(HttpContext context)
    {
        var isHtml = context.Response.ContentType?.ToLower().Contains("text/html");
        Stream responseBody = context.Response.Body;
        using (var memoryStream = new MemoryStream())
        {
            context.Response.Body = memoryStream;

            await _next(context);

            if (context.Response.StatusCode == 200 && isHtml.GetValueOrDefault())
            {
                memoryStream.Position = 0;
                string html = new StreamReader(memoryStream).ReadToEnd();
                // save the HTML

            }
            memoryStream.Position = 0;
            await memoryStream.CopyToAsync(responseBody);
        }
    }
}

Replace the // save the HTML with some code to persist the HTML as required. Register the Middleware in your Startup's Configure method early:

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseExceptionHandler("/Error");
        app.UseHsts();
    }
    app.UseMiddleware<ResponseToStringMidleware>();
    ...
}

Further infomration: Middleware in Razor Pages