Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Improve the readme Quick Start #15

Merged
merged 1 commit into from
Dec 3, 2020
Merged

Improve the readme Quick Start #15

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
32 changes: 30 additions & 2 deletions README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -93,9 +93,37 @@ Please find installation guides and notes for other project types (for example `
the library will have an **explicit dependency** on the `Nullable` package.
3. **Build the project** <br/>
Ensure that the project compiles. If a build error occurs, you will most likely have to update
the C# language version.
the C# language version (see next step).
4. **Enable usage of the attributes** <br/>
Still in your `.csproj` file you need to activate the feature to fully use it.
The following activation sample is what seems to be the most common use case. But do not hesitate to look at my [guides](https://github.com/manuelroemer/Nullable/wiki) for other considerations.

Afterwards, you can immediately start using the attributes.
```xml
<PropertyGroup>
<!-- a sample list of target frameworks including legacy ones. This list must depend on your needs. -->
<TargetFrameworks>net472;netstandard2.0;netstandard2.1;netcoreapp3.0</TargetFrameworks>
<!-- force lang version at least to C#8 to be able to use the feature with all frameworks.-->
<LangVersion>8.0</LangVersion> <!-- or --> <LangVersion>latest</LangVersion>
<!-- enable the feature but without warning for legacy frameworks to avoid false positives. -->
<Nullable>annotations</Nullable>
<!-- enable the feature including warnings only on top of the most recent framework you target. -->
<!-- it will serve as a reference for warnings for all others. -->
<Nullable Condition="'$(TargetFramework)' == 'netcoreapp3.0'">enable</Nullable>
</PropertyGroup>
```

5. **Build the project and fix warnings** <br/>
If your not starting a new project you will probably get a lot of warnings now, since your code base is not yet annotated.
If you don't expect to fix all right now, one solution could be to disable the feature in all files before reviewing each file one by one.
For that run the following powershell script to add a `#nullable disable` directive at the top of each file.

```PowerShell
Get-ChildItem -Recurse -Filter *.cs | ForEach-Object {
"#nullable disable`n" + (Get-Content $_ -Raw) | Set-Content $_
}
```

You should now be ready to play with nullable references and the attributes even when targeting legacy frameworks.


## Compiler Constants
Expand Down