Monaco YAML

YAML language plugin for the Monaco Editor. It provides the following features when editing YAML files:

• Code completion, based on JSON schemas or by looking at similar objects in the same file
• Hovers, based on JSON schemas
• Validation: Syntax errors and schema validation
• Formatting using Prettier
• Document Symbols
• Automatically load remote schema files (by enabling DiagnosticsOptions.enableSchemaRequest)
• Links from JSON references.

Schemas can also be provided by configuration. See here for the API that the plugin offers to configure the YAML language support.

Installation

npm install monaco-yaml

Usage

Import monaco-yaml and configure it before an editor instance is created.

import { editor, Uri } from 'monaco-editor';
import { setDiagnosticsOptions } from 'monaco-yaml';

// The uri is used for the schema file match.
const modelUri = Uri.parse('a://b/foo.yaml');

setDiagnosticsOptions({
  enableSchemaRequest: true,
  hover: true,
  completion: true,
  validate: true,
  format: true,
  schemas: [
    {
      // Id of the first schema
      uri: 'http://myserver/foo-schema.json',
      // Associate with our model
      fileMatch: [String(modelUri)],
      schema: {
        type: 'object',
        properties: {
          p1: {
            enum: ['v1', 'v2'],
          },
          p2: {
            // Reference the second schema
            $ref: 'http://myserver/bar-schema.json',
          },
        },
      },
    },
    {
      // Id of the first schema
      uri: 'http://myserver/bar-schema.json',
      schema: {
        type: 'object',
        properties: {
          q1: {
            enum: ['x1', 'x2'],
          },
        },
      },
    },
  ],
});

editor.create(document.createElement('editor'), {
  // Monaco-yaml features should just work if the editor language is set to 'yaml'.
  language: 'yaml',
  model: editor.createModel('p1: \n', 'yaml', modelUri),
});

Also make sure to register the web worker.

Examples

A demo is available on monaco-yaml.js.org.

A running example:

Some usage examples can be found in the examples directory.

Contributing

Please see our contributing guidelines

Credits

Originally @kpdecker forked this repository from monaco-json by @microsoft and rewrote it to work with yaml-language-server instead. Later the repository maintenance was taken over by @pengx17. Eventually the repository was tranferred to the account of @remcohaszing, who is currently maintaining this repository with the help of @fleon and @yazaabed.

The heavy processing is done in yaml-language-server, best known for being the backbone for vscode-yaml. This repository provides a thin layer to add functionality provided by yaml-language-server into monaco-editor.

License

MIT