context#

The generator plugin exports a function by default in the main file, and the function parameter is context. All APIs provided by the generator plugin are provided by this context.

Types#

Let's first understand the type definition of context:

export interface IPluginContext {
  locale?: string;
  addInputBefore: (key: string, input: Schema) => void;
  addInputAfter: (key: string, input: Schema) => void;
  setInput: (key: string, field: string, value: unknown) => void;
  setInputValue: (value: Record<string, unknown>) => void;
  setDefaultConfig: (value: Record<string, unknown>) => void;
  isFileExist: (fileName: string) => Promise<boolean>;
  readDir: (dir: string) => Promise<string[]>;
  setGitMessage: (gitMessage: string) => void;
  onForged: (func: PluginForgedFunc) => void;
  afterForged: (func: PluginAfterForgedFunc) => void;
}

The contents provided by context can be mainly divided into three categories:

• Get the information of the current generator execution environment.

• Operate input.

• Generator plugin lifecycle function.

The generator plugin APIs will be introduced from these three categories below.

Get Information#

locale#

Gets the language of the generator plugin execution environment. @modern-js/create provides two languages, zh and en, which correspond to these two values.

isFileExist#

Checks whether a file exists. We often need to confirm whether the target project file exists before defining the operation. This API can be used directly for this purpose.

For example, we need to find out if the package.json file exists and then do someing:

const isExist = await context.isFileExist('package.json');
if (isExist) {
    ...
}

readDir#

Gets the file list in a folder. We often need to get the file list under the target project folder before defining the operation. This API can be used directly for this purpose.

For example, we need to get all files under the src folder and then do someing:

const files = await context.readDir('src');

files.map(name => {
    ...
});

Input Operations#

The key parameter used in input operations can refer to Configuration Parameters and use the key under the solution’s scheme, that is, it does not support solution and scenes.

The input parameter in input operations corresponds to the schema type described in Input.

addInputBefore#

Adds a question before the specified input key.

For example:

context.addInputBefore('packageManager', {
  type: 'object',
  properties: {
    language: {
      type: 'string',
      title: 'Please select the programming language:',
      enum: [
        { label: 'TS', value: 'ts' },
        { label: 'ES6+', value: 'js' },
      ],
    },
  },
});

addInputAfter#

Adds a question after the specified input key.

For example:

context.addInputAfter('packageManager', {
  type: 'object',
  properties: {
    language: {
      type: 'string',
      title: 'Please select the programming language:',
      enum: [
        { label: 'TS', value: 'ts' },
        { label: 'ES6+', value: 'js' },
      ],
    },
  },
});

setInput#

Sets the attributes of the specified input key.

For example, set the title attribute of packageName:

context.setInput('packageName', 'title', "Name");

setInputValue#

Sets the default value of the specified input key.

For example, set the default value of packageManager:

context.setInputValue({
  packageManager: 'npm',
});

setDefaultConfig#

Sets the default value of the specified input key.

For example, set the default value of packageManager:

context.setDefaultConfig({
  packageManager: 'npm',
});

setGitMessage#

Sets the initial git commit message. Modern.js defaults to the git initialization commit message as feat: init, which can be modified by this function.

Lifecycle Functions#

The lifecycle functions are relatively complex and will be introduced separately in the following two sections, onForged and afterForged.