Blazor WASM Support#

You can use Blazor WASM with the Datasync Community Toolkit; however, there are some signficant problems:

  1. In the general case, you cannot use SQLite for offline storage.
  2. You will have to suppress the WASM0001 warning for sqlite.

Do not use offline mode#

It is possible to use offline mode by storing the SQLite database in local storage within the browser. When you start up your application, you restore the SQLite in-memory database into memory; on a regular basis, you write the SQLite database to local storage. However, this system severely affects performance within the browser and large synchronizations will cause the local storage to overflow. As a result of these problems, it is not recommended, nor is it supported.

Suppress the WASM0001 warning#

When compiling the WASM client, you will see warning WASM0001. This is a harmless warning that indicates SQLite is not available. However, you may be running using “Warnings as Errors”. The most appropriate solution is to suppress the WASM0001 warning in your client .csproj file as follows:

<PropertyGroup>
    <NoWarn>$(NoWarn);WASM0001</NoWarn>
</PropertyGroup>

Alternatively, you may also use the following to keep WASM0001 as a warning even when using “Warnings as Errors”:

<PropertyGroup>
  <WarningsNotAsErrors>$(WarningsNotAsErrors);WASM0001</WarningsNotAsErrors>
</PropertyGroup>

This will suppress the harmless SQLite warning that appears when building Blazor WASM applications that reference libraries containing SQLite dependencies (even when not using SQLite directly).

Sample#

We have a Blazor WASM sample in our sample set: samples/todoapp-blazor-wasm. This sample comprises a server (which uses an in-memory EF Core database) combined with a Blazor Web Assembly client.