blazor server query string: how to get data only one time

Question

On blazor page we need to get data from query string.

We use OnInitialized event to read data:

for example:

protected override void OnInitialized()
    {
        var uri = NavManager.ToAbsoluteUri(NavManager.Uri);
        if (QueryHelpers.ParseQuery(uri.Query).TryGetValue("initialCount", out var _initialCount))
        {
            currentCount = Convert.ToInt32(_initialCount);
        }
    }

But we use prerendering:

@(await Html.RenderComponentAsync<App>(RenderMode.ServerPrerendered))

and this code executes two time.

It's a problem, because we need to reach database with these parameters, but we don't want to do it twice.

Disable prerendering is not an option.

Tried to move code to other events, for example to OnParametersSet, but it executes twice too.

Maybe we can check it event executes first or second time and use this condition?

Or some other options?

MrC aka Shaun Curtis · Accepted Answer · 2021-12-11 10:09:24Z

2

I don't think there's a safe way to do this in .Net5 - you've tagged your Question with .Net5.

.Net6 adds persist-prerendered-state, which I think will solve your problem. Here's a link to the MS-Docs page that explains how to use it:

MS-Docs - Persist prerendered state

answered Dec 11, 2021 at 10:09

MrC aka Shaun Curtis

32.4k3 gold badges27 silver badges56 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

blazor server query string: how to get data only one time

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related