@gasket/plugin-metadata

@gasket/plugin-metadata

Metadata is the information about the registered plugins and presets, available to plugin lifecycle hooks. This data can be used in various was for plugins, most notably the @gasket/plugin-docs which uses it to collate docs for an app.

Installation

This is a default plugin in newly create Gasket apps.

Actions

getMetadata

Get all the metadata for the configured plugins and modules.

const metadata = await gasket.actions.getMetadata();

Lifecycles

metadata

Describe metadata for a plugin and optionally its supporting modules.

Example

This plugin implements the metadata lifecycle, which plugins can use to modify its own metadata at runtime. Whatever is returned will replace the existing metadata.

// gasket-plugin-example.js
export default {
  name: 'example',
  hooks: {
    /**
     * @param {Gasket} gasket - The Gasket API
     * @param {PluginData} data - This plugin's initial metadata
     * @returns {Object}
     */
    async metadata(gasket, data) {
      return {
        ...data,
        // adding extra data to this plugin's metadata
        extra: 'information',
        // add metadata for details of this plugin
        lifecycles: [{
          name: 'some-data',
          description: 'Allows plugins to do something with data',
          method: 'exec',
          parent: 'start'
        }],
        // Metadata for these modules will be loaded
        // Declare as strings or objects with additional data
        modules: [
          {
            name: 'module-name',
            version: '7.0.0',
            description: 'module-name despcrition',
            link: 'README.md'
          }
        ]
      }
    },
    /**
     * An example lifecycle hook which utilizes metadata
     *
     * @param {Gasket} gasket - The Gasket API
     */
    async example(gasket) {
      const { metadata } = gasket;

      if (metadata.plugins.find(pluginData => pluginData.name === 'gasket-plugin-something')) {
        // only perform some action if a certain plugin is also registered
      }
    }
  }
}

Usage

Beside the lifecycles available to plugins, metadata can also be described for modules.

Modules

Lastly, modules can describe metadata by defining a gasket.metadata property in the package.json which will get expanded to the ModuleData:

{
  "name": "example",
  "version": "1.2.3",
  "gasket": {
    "metadata": {
      "guides": [
        {
          "name": "Example Guide",
          "description": "How to do something",
          "link": "docs/example.md"
        }
      ]
    }
  }
}

This is especially useful to surface guides with Gasket docs for supporting packages that are intended to be used with Gasket, but are not plugins.

Access

Plugins and apps can read from the metadata object by using the getMetadata Gasket action.

Access example

Back to our example plugin, let's see how we can access details about an installed module, and put is some conditional logic.

// gasket-plugin-example.js
import semver from 'semver';

export default {
  name: 'example',
  hooks: {
    // We need access to metadata during build
    async build(gasket) {
      const metadata = await gasket.actions.getMetadata()
      // ... use metadata
    }
  }
};

License

MIT