Posted by Anuraj on Saturday, April 28, 2018 Reading time :2 minutes
This post is about Working with Microsoft Library Manager for ASP.NET Core. Recently ASP.NET Team posted a blog - about bower deprecation. And in there they mentioned about a new tool called Library Manager - Library Manager (“LibMan” for short) is Visual Studio’s experimental client-side library acquisition tool. It provides a lightweight, simple mechanism that helps users find and fetch library files from an external source (such as CDNJS) and place them in your project. LibMan is not a package management system. If you’re using npm / yarn / (or something else), you can continue use it. LibMan was not developed as a replacement for these tools.
In this post I am explaining how you can use Library manager for an ASP.NET Core project from dotnet CLI.
First I am creating an empty project using -
dotnet new web -o libmandemo. Once the project is created, you can add a file,
libman.json, which helps to configure which all libraries you need to download, from where you need to downlaod and where is your target folder, like under
wwwroot folder. So here is the typical libman.json file look like, which download bootstrap and jquery, from cdnjs.
And will be downloaded to the
lib folder under
wwwroot. Next you need to add reference of
Microsoft.Web.LibraryManager.Build - this package will help to download script files as part of MS Build task. You can add this using
dotnet add package Microsoft.Web.LibraryManager.Build command.
Now you’re ready, build your app using
dotnet build command, which will download and install JQuery and bootstrap.
As per the ASP.NET Team blog, there is an option in Visual Studio UI to do all this, but due to some strage reason, it is not available in the updated preview version of Visual Studio (VS 2017 15.7 Preview 5).
Also you might get some errors like this while running the
dotnet build command.
It is because the Microsoft.Web.LibraryManager.Build.targets tries to use a netstandard1.3 version of the Microsoft.Web.LibraryManager.dll, but only netstandard1.5 is available. As a work around open the
Microsoft.Web.LibraryManager.Build.targets file from
C:\Users\[username]\.nuget\packages\microsoft.web.librarymanager.build\1.0.20\build location, and look for
netstandard text, you will be able to find it 5th line, with
netstandard1.3 mentioned in the path value, modify it to
netstandard1.5. Save the file and run the
dotnet build command again. Now it will run the build command properly without any problem.
LibMan is recommended choice for following scenarios.
Here is some useful resources.
Happy Programming :)
What do you think? I would like to hear your thoughts, suggestions, and questions in the comments section below.