While developing Angular applications in Visual Studio 2019 & Visual Studio Code following compile time error is shown:

TS1219 Experimental support for decorators is a feature that is subject to change in a future release. Specify ‘–experimentalDecorators’ to remove this warning.

Visual Studio Fix:

I am using Visual Studio 2019 and fixed the issue in it, it might work in other versions as well.

Add the following lines in .csproj file:

  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|AnyCPU'">    
    <TypeScriptExperimentalDecorators>True</TypeScriptExperimentalDecorators>
    <TypeScriptEmitDecoratorMetadata>True</TypeScriptEmitDecoratorMetadata>
  </PropertyGroup>

Tip: You can edit .csproj file by unloading the project, right click and select Edit .csproj file in solution explorer.

Here is the example .csproj file after adding the above options:

<Project Sdk="Microsoft.NET.Sdk.Web"> <PropertyGroup> <TargetFramework>netcoreapp2.2</TargetFramework> <TypeScriptCompileBlocked>true</TypeScriptCompileBlocked> <TypeScriptToolsVersion>Latest</TypeScriptToolsVersion> <IsPackable>false</IsPackable> <SpaRoot>ClientApp\</SpaRoot> <DefaultItemExcludes>$(DefaultItemExcludes);$(SpaRoot)node_modules\**</DefaultItemExcludes> <!-- Set this to true if you enable server-side prerendering --> <BuildServerSideRenderer>false</BuildServerSideRenderer> </PropertyGroup> <ItemGroup> <PackageReference Include="Microsoft.AspNetCore.App" /> <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.2.0" PrivateAssets="All" /> <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.2.3" /> </ItemGroup> <ItemGroup> <!-- Don't publish the SPA source files, but do show them in the project files list --> <Content Remove="$(SpaRoot)**" /> <None Remove="$(SpaRoot)**" /> <None Include="$(SpaRoot)**" Exclude="$(SpaRoot)node_modules\**" /> </ItemGroup> <ItemGroup> <None Remove="ClientApp\src\app\privacy\privacy.component.ts" /> <None Remove="ClientApp\src\app\terms\terms.component.ts" /> </ItemGroup> <ItemGroup> <TypeScriptCompile Include="ClientApp\src\app\privacy\privacy.component.ts" /> <TypeScriptCompile Include="ClientApp\src\app\terms\terms.component.ts" /> </ItemGroup> <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|AnyCPU'"> <TypeScriptExperimentalDecorators>True</TypeScriptExperimentalDecorators> <TypeScriptEmitDecoratorMetadata>True</TypeScriptEmitDecoratorMetadata> </PropertyGroup> <Target Name="DebugEnsureNodeEnv" BeforeTargets="Build" Condition=" '$(Configuration)' == 'Debug' And !Exists('$(SpaRoot)node_modules') "> <!-- Ensure Node.js is installed --> <Exec Command="node --version" ContinueOnError="true"> <Output TaskParameter="ExitCode" PropertyName="ErrorCode" /> </Exec> <Error Condition="'$(ErrorCode)' != '0'" Text="Node.js is required to build and run this project. To continue, please install Node.js from https://nodejs.org/, and then restart your command prompt or IDE." /> <Message Importance="high" Text="Restoring dependencies using 'npm'. This may take several minutes..." /> <Exec WorkingDirectory="$(SpaRoot)" Command="npm install" /> </Target> <Target Name="PublishRunWebpack" AfterTargets="ComputeFilesToPublish"> <!-- As part of publishing, ensure the JS resources are freshly built in production mode --> <Exec WorkingDirectory="$(SpaRoot)" Command="npm install" /> <Exec WorkingDirectory="$(SpaRoot)" Command="npm run build -- --prod" /> <Exec WorkingDirectory="$(SpaRoot)" Command="npm run build:ssr -- --prod" Condition=" '$(BuildServerSideRenderer)' == 'true' " /> <!-- Include the newly-built files in the publish output --> <ItemGroup> <DistFiles Include="$(SpaRoot)dist\**; $(SpaRoot)dist-server\**" /> <DistFiles Include="$(SpaRoot)node_modules\**" Condition="'$(BuildServerSideRenderer)' == 'true'" /> <ResolvedFileToPublish Include="@(DistFiles->'%(FullPath)')" Exclude="@(ResolvedFileToPublish)"> <RelativePath>%(DistFiles.Identity)</RelativePath> <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory> </ResolvedFileToPublish> </ItemGroup> </Target> </Project> read more

ASP.NET SignalR is a library for ASP.NET developers that simplifies the process of adding real-time web functionality to applications. Real-time web functionality is the ability to have server code push content to connected clients instantly as it becomes available, rather than having the server wait for a client to request new data – Microsoft

Normally server sends notifications to clients when communication is initiated by some client but there are situations when we want server to push data to clients even there is no request from any clients.
Here is step by step procedure to do so.

[the_ad id=”181″]

Step 1
Add hub class, right click (on the App_Code in case of website project or appropriate folder in case of web application project), select Add and then Add New Item. Select the SignalR Hub Class template, give it a name say BroadcasterHub and click Add.
Your class should look like below:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;
[HubName("mainBroadcasterHub")]
public class BroadcasterHub : Hub
{
private readonly Broadcaster _broadcaster;
public BroadcasterHub() : this(Broadcaster.Instance) { }

public BroadcasterHub(Broadcaster broadcaster)
{
_broadcaster = broadcaster;
}
}
read more