BlazorMonaco

Blazor component for Microsoft's Monaco Editor which powers Visual Studio Code.

Some less-frequently used Monaco Editor features are currently missing, but the whole basic feature set is supported. The package will be updated to cover all the features and use cases over time. Any contributions, comments or suggestions are greatly welcome. Please feel free to contact me at twitter/serdarciplak or via GitHub.

Current version of BlazorMonaco :

Uses Monaco Editor v0.34.1
Supports netstandard2.0, net5.0, net6.0 and net7.0

Demo

You can see a working sample WebAssembly app here.

Get Started

Add the NuGet package to your Blazor project.

dotnet add package BlazorMonaco
// or
Install-Package BlazorMonaco

Add the below script tags to your index.html file. Please note that these script tags must be placed before the script tag for the blazor.webassembly.js file.

<script src="_content/BlazorMonaco/jsInterop.js"></script>
<script src="_content/BlazorMonaco/lib/monaco-editor/min/vs/loader.js"></script>
<script src="_content/BlazorMonaco/lib/monaco-editor/min/vs/editor/editor.main.js"></script>

Everything resides in two namespaces. So, you can add the following using directives to your root _Imports.razor file, or any other place you may need them.

@using BlazorMonaco
@using BlazorMonaco.Editor

Code Editor

Adding an editor instance

To add a new editor instance, you just need to add a StandaloneCodeEditor component in your razor file.

<StandaloneCodeEditor Id="my-editor-instance-id" />

Providing custom options

If you set the ConstructionOptions parameter and provide a method that returns a StandaloneEditorConstructionOptions instance, it will be called when the instance is created and those options will be used to initialize the editor.

<StandaloneCodeEditor Id="my-editor-instance-id" ConstructionOptions="EditorConstructionOptions" />

Then, add that method to your razor file's @code block and set the initial options for your editor instance.

private StandaloneEditorConstructionOptions EditorConstructionOptions(StandaloneCodeEditor editor)
{
	return new StandaloneEditorConstructionOptions
	{
		AutomaticLayout = true,
		Language = "javascript",
		Value = "function xyz() {\n" +
				"   console.log(\"Hello world!\");\n" +
				"}"
	};
}

Editor events

You can add listeners to editor events like OnDidKeyUp or OnDidPaste for any custom job to be done when that event occurs.

<StandaloneCodeEditor Id="my-editor-instance-id" OnDidChangeCursorPosition="EditorDidChangeCursorPosition" />

Then, add your event listener method to your razor file's @code block.

private void EditorDidChangeCursorPosition(CursorPositionChangedEvent eventArgs)
{
	Console.WriteLine("EditorDidChangeCursorPosition");
}

Diff Editor

Adding a diff editor instance

To add a new diff editor instance, you just need to add a StandaloneDiffEditor component in your razor file.

<StandaloneDiffEditor Id="my-editor-instance-id" />

Access to inner editor instances and events

StandaloneDiffEditor class has two properties named OriginalEditor and ModifiedEditor to access the inner editors. They're regular code editors. So, you can use them like any other StandaloneCodeEditor instances.
You can register to inner editor events via the helper event callback parameters of the StandaloneDiffEditor.

<StandaloneDiffEditor Id="my-editor-instance-id" OnKeyUpOriginal="OnKeyUpOriginal" OnKeyUpModified="OnKeyUpModified" />

And then, add the callback methods to your razor file's @code block.

private void OnKeyUpOriginal(KeyboardEvent keyboardEvent)
{
	Console.WriteLine("OnKeyUpOriginal : " + keyboardEvent.Code);
}
private void OnKeyUpModified(KeyboardEvent keyboardEvent)
{
	Console.WriteLine("OnKeyUpModified : " + keyboardEvent.Code);
}

Customization

Css styling

There are 3 css selectors you can use to add/edit css styles for your editors.
- The main html element of all editor instances contains the monaco-editor-container css class.
- The Id value you set for your razor component is also set as the id of its html element.
- You can provide a string in the CssClass property of an editor instance. That value will be added to the class attribute of its html element.

<StandaloneCodeEditor Id="my-editor-id" CssClass="my-editor-class" />

.monaco-editor-container { /* for all editor instances */
	height: 100px;
}

/* or */

#my-editor-id { /* for a specific editor instance */
	height: 100px;
}

/* or */

.my-editor-class { /* for a specific editor instance */
	height: 100px;
}

⚠️ Note : As an html element cannot set its height disregarding where it's placed in, BlazorMonaco cannot manage editor instance heights. So, if you don't do that yourself, editor instances may have a height of 0px and be invisible. Please don't forget to set your editor instance heights as you need.

Custom themes

You can define custom themes using the DefineTheme method. Just make sure that you don't call DefineTheme before any editor instance is initialized. BlazorMonaco needs an IJSRuntime instance to call JavaScript methods and it gets one when the first instance is initialized.

await BlazorMonacoGlobals.DefineTheme("my-custom-theme", new StandaloneThemeData
{
	Base = "vs-dark",
	Inherit = true,
	Rules = new List<TokenThemeRule>
	{
		new TokenThemeRule { Background = "363636", Foreground = "E0E0E0" },
		new TokenThemeRule { Token = "keyword", Foreground = "59ADFF" },
		new TokenThemeRule { Token = "operator.sql", Foreground = "59ADFF" },
		new TokenThemeRule { Token = "number", Foreground = "66CC66" },
		new TokenThemeRule { Token = "string.sql", Foreground = "E65C5C" },
		new TokenThemeRule { Token = "comment", Foreground = "7A7A7A" }
	},
	Colors = new Dictionary<string, string>
	{
		["editor.background"] = "#363636",
		["editorCursor.foreground"] = "#E0E0E0",
		["editorLineNumber.foreground"] = "#7A7A7A"
	}
});

After defining your custom theme, you can call the SetTheme method at any time with your custom theme name to set it active.

await BlazorMonacoGlobals.SetTheme("my-custom-theme");

DeltaDecorations

You can add, edit and remove decorations to editors via the DeltaDecorations and ResetDeltaDecorations methods.

private async Task EditorOnDidInit()
{
	var newDecorations = new ModelDeltaDecoration[]
	{
		new ModelDeltaDecoration
		{
			Range = new BlazorMonaco.Range(3,1,3,1),
			Options = new ModelDecorationOptions
			{
				IsWholeLine = true,
				ClassName = "decorationContentClass",
				GlyphMarginClassName = "decorationGlyphMarginClass"
			}
		}
	};

	decorationIds = await _editor.DeltaDecorations(null, newDecorations);
	// You can now use 'decorationIds' to change or remove the decorations
}

Using custom Monaco Editor setup

If you've made changes to Monaco Editor, and need to use this edited version instead of the unmodified version packed with BlazorMonaco, just change the paths to monaco editor resources in your index.html file.

<script src="_content/BlazorMonaco/jsInterop.js"></script>
<script>var require = { paths: { vs: 'my-path/monaco-editor/min/vs' } };</script>
<script src="my-path/monaco-editor/min/vs/loader.js"></script>
<script src="my-path/monaco-editor/min/vs/editor/editor.main.js"></script>

Documentation

As BlazorMonaco is just a bridge between JavaScript and Blazor, you can use Monaco Editor's documentation.

Migration Guide

After a major version update (like from v2.x.x to v3.x.x), you may need to make some changes in your integration. Please see the MIGRATE.md for details.

Change Log

You can view the history and the changes in the CHANGELOG.md

License

MIT, see the LICENSE file for detail.

Robbware / BlazorMonaco