Asp.net Core TempData lifetime and search term - asp.net

Question

In my index I added a search field.
When user enter a search term and click filter the index (Index) is filtered.
So far so good.
What I would like to achieve is that if the user performs other operations (edit, details, delete, etc) in the same controller and returns to the Index, I would like the search to be restored.
To do this, I used TempData but without success.
In the various forums / tutorials I found conflicting about lifetime.
Some say:
lifetime of an object placed in TempData is exactly one additional
request.
See this stackoverflow article
On another site i found:
Data stored in TempData will be alive in the cookie until you read it
from the TempData dictionary.
See this article
So where is the truth:
Only one sub request or when I read the TempData ?
My tests says the second: "until you read it" (or when expire)
Here my code on startup
public void ConfigureServices(IServiceCollection services)
{
// [..]
// Relevant code only
services.AddDistributedMemoryCache();
services.AddSession(options =>
{
// Set a short timeout for easy testing.
options.IdleTimeout = TimeSpan.FromMinutes(15);
options.CookieHttpOnly = true;
});
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
// [..]
// Relevant code only
app.UseSession();
}
On my controller
public async Task<IActionResult> Index(int page, string search)
{
search = search ?? TempData["Search"]?.ToString();
// Query with search data
TempData["search"] = search;
}
If I search on this controller the TempData save the search term.
If, after searching in the list, I navigate to other pages and then return here, the search term is still present
I already know that exist .Keep, .Peek and other methods for manage the TempData
Questions
How manage the search term between actions ?
How work the TempData (until re-read or on ONE addictional request) ?

Answer 1

Judging by many older Stack Overflow posts and articles out there, it seems TempData only lasted until the next request in prior versions of ASP.NET. However, that is not the case as of .NET Core according to Microsoft:
ASP.NET Core exposes the Razor Pages TempData or Controller TempData. This property stores data until it's read in another request. The Keep(String) and Peek(string) methods can be used to examine the data without deletion at the end of the request. Keep marks all items in the dictionary for retention.
Another claim I see repeatedly about TempData is how it is implemented using sessions, but that isn't the default mechanism as of .NET Core:
The cookie-based TempData provider is enabled by default. To enable the session-based TempData provider, use the AddSessionStateTempDataProvider extension method.
Source:
https://learn.microsoft.com/en-us/aspnet/core/fundamentals/app-state?view=aspnetcore-3.1#tempdata