Components-Generator.js

This is a tool to automatically generate .jsonld component files from TypeScript classes for the Components.js dependency injection framework.

Before you use this tool, it is recommended to first read the Components.js documentation.

Getting started

1. Install as a dev dependency

npm install -D componentsjs-generator

or

yarn add -D componentsjs-generator

2. Declare components in package.json

If you are already using Components.js, you already have this.

Add the following entry to package.json:

{
  ...
  "lsd:module": true,
  ...
}

On each line, make sure to replace my-package with your package name.

3. (optional) Add generate script

Call componentsjs-generator as a npm script by adding a scripts entry to your package.json:

{
  ...,
  "scripts": {
    ...
    "build": "npm run build:ts && npm run build:components",
    "build:ts": "tsc",
    "build:components": "componentsjs-generator",
    "prepare": "npm run build",
    ...
  }
}

This is only a recommended way of calling componentsjs-generator, you are free to call it in a different way that better suits your pipeline.

4. (optional) Ignore generated components files

Since we automatically generate the components files, we do not have to check them into version control systems like git. So we can add the following line to .gitignore:

components

If you do this, make sure that the components folder is published to npm by adding the following to your package.json:

{
  ...
  "files": [
    ....
    "components/**/*.jsonld",
    "config/**/*.json",
    ....
  ],
  ....
}

Usage

When invoking componentsjs-generator, this tool will automatically generate .jsonld components files for all TypeScript files that are exported by the current package.

For monorepos, multiple package paths may be provided.

Generates component file for a package
Usage:
  componentsjs-generator
  Arguments:
       path/to/package         The directories of the packages to look in, defaults to working directory
  Options:
       -p path/to/package      The directory of the package to look in, defaults to working directory
       -s lib                  Relative path to directory containing source files, defaults to 'lib'
       -c components           Relative path to directory that will contain components files, defaults to 'components'
       -e jsonld               Extension for components files (without .), defaults to 'jsonld'
       -i ignore-classes.json  Relative path to an optional file with class names to ignore
       -r prefix               Optional custom JSON-LD module prefix
       --lenient               If unsupported language features must produce a warning instead of an error
       --debugState            If a 'componentsjs-generator-debug-state.json' file should be created with debug information
       --help                  Show information about this command

Note: This generator will read .d.ts files, so it is important that you invoke the TypeScript compiler (tsc) before using this tool.

Configuration files

While options passed to the CLI tool will always take precedence, it is possible to add a .componentsjs-generator-config.json file to your project to define your configuration.

The following shows an example of the possible options:

{
  "source": "lib",
  "destination": "components",
  "extension": "jsonld",
  "ignorePackagePaths": ["path/to/package-ignored1", "path/to/package-ignored2"],
  "ignoreComponents": ["Class1", "Class2"],
  "logLevel": "info",
  "modulePrefix": "myprefix",
  "debugState": "true",
  "hardErrorUnsupported": false
}

When invoking componentsjs-generator, the tool will look for .componentsjs-generator-config.json in the current working directory. If it can not find one, it will recursively go look into the parent directories until it either finds one or is at the root.

Ignoring classes

If you don't want components to be generated for certain classes, then you can either add it to the ignoreComponents array of the .componentsjs-generator-config.json file (as explained above), or you can pass a JSON file to the -i option containing an array of class names to skip.

For example, invoking componentsjs-generator -i ignore-classes.json will skip BadClass if the contents of ignore-classes.json are:

[
  "BadClass"
]

If you are looking for a way to ignore parameters, see the @ignored argument tag below.

How it works

For each exported TypeScript class, its constructor will be checked, and component parameters will be generated based on the TypeScript type annotations.

Example

TypeScript class:

/**
 * This is a great class!
 */
export class MyClass extends OtherClass {
  /**
   * @param paramA - My parameter
   */
  constructor(paramA: boolean, paramB: number, paramC: string[]) {

  }
}

Component file:

{
  "@context": [
    "https://linkedsoftwaredependencies.org/bundles/npm/@solid/community-server/^1.0.0/components/context.jsonld"
  ],
  "@id": "npmd:my-package",
  "components": [
    {
      "@id": "ex:MyFile#MyClass",
      "@type": "Class",
      "requireElement": "MyClass",
      "extends": "ex:OtherFile#OtherClass",
      "comment": "This is a great class!",
      "parameters": [
        {
          "@id": "ex:MyFile#MyClass_paramA",
          "range": "xsd:boolean",
          "comment": "My parameter"
        },
        {
          "@id": "ex:MyFile#MyClass_paramB",
          "range": "xsd:integer"
        },
        {
          "@id": "ex:MyFile#MyClass_paramC",
          "range": {
            "@type": "ParameterRangeArray",
            "parameterRangeValue": "xsd:integer"
          }
        }
      ],
      "constructorArguments": [
        { "@id": "ex:MyFile#MyClass_paramA" },
        { "@id": "ex:MyFile#MyClass_paramB" },
        { "@id": "ex:MyFile#MyClass_paramC" }
      ]
    }
  ]
}

Arguments

Each argument in the constructor of the class must be one of the following:

• A primitive type such as boolean, number, string, which will be mapped to an XSD type
• Another class, which will be mapped to the component @id.
• A record or interface containing key-value pairs where each value matches one of the possible options. Nesting is allowed.
• Reference to a generic type that is defined on the class.
• An array, keyof, tuple, union, or intersection over any of the allowed types.

Here is an example that showcases all of these options:

import {Logger} from "@comunica/core";
export class SampleActor {
   constructor(
     args: HashArg,
     number: number,
     component: Logger,
     array: HashArg[],
     complexComposition: (SomeClass & OtherClass) | string,
     complexTuple: [ number, SomeClass, ...string[] ],
     optional?: number,
   ) {}
}
export interface HashArg {
   args: NestedHashArg;
   array: NestedHashArg[];
}
export interface NestedHashArg extends ExtendsTest {
   test: boolean;
   component: Logger;
}
export interface ExtendsTest {
   string: string;
}

Argument tags

Using comment tags, arguments can be customized.

Tags

Default values

Default values accept a microsyntax, in which several types of values may be provided:

• Literal values: @default {abc}
• IRI values: @default {}
• Blank-node-based instantiation: @default {a }
• IRI-based instantiation: @default { a }

Examples

Tagging constructor fields:

TypeScript class:

export class MyActor {
    /**
     * @param myByte - This is an array of bytes @range {byte}
     * @param ignoredArg - @ignored
     */
    constructor(myByte: number[], ignoredArg: string) {

    }
}

Component file:

{
  "components": [
    {
      "parameters": [
        {
          "@id": "my-actor#TestClass#myByte",
          "range": {
            "@type": "ParameterRangeArray",
            "parameterRangeValue": "xsd:byte"
          },
          "comment": "This is an array of bytes"
        }
      ],
      "constructorArguments": [
        {
          "@id": "my-actor#TestClass#myByte"
        }
      ]
    }
  ]
}

Tagging constructor fields as raw JSON:

TypeScript class:

export class MyActor {
    /**
     * @param myValue - Values will be passed as parsed JSON @range {json}
     * @param ignoredArg - @ignored
     */
    constructor(myValue: any, ignoredArg: string) {

    }
}

Component file:

{
  "components": [
    {
      "parameters": [
        {
          "@id": "my-actor#TestClass#myValue",
          "range": "rdf:JSON",
          "comment": "Values will be passed as parsed JSON"
        }
      ],
      "constructorArguments": [
        {
          "@id": "my-actor#TestClass#myValue"
        }
      ]
    }
  ]
}

When instantiating TestClass as follows, its JSON value will be passed directly into the constructor:

{
  "@id": "ex:myInstance",
  "@type": "TestClass",
  "myValue": {
    "someKey": {
      "someOtherKey1": 1,
      "someOtherKey2": "abc"
    }
  }
}

Tagging interface fields:

TypeScript class:

export class MyActor {
  constructor(args: IActorBindingArgs) {
    super(args)
  }
}

export interface IActorBindingArgs {
  /**
   * This field is very important
   * @range {float}
   * @default {5.0}
   */
   floatField: number;
}

Component file:

{
  "components": [
    {
      "parameters": [
        {
          "@id": "my-actor#floatField",
          "range": "xsd:float",
          "default": "5.0",
          "comment": "This field is very important"
        }
      ],
      "constructorArguments": [
        {
          "fields": [
            {
              "keyRaw": "floatField",
              "value": "my-actor#floatField"
            }
          ]
        }
      ]
    }
  ]
}

License

Components.js is written by Ruben Taelman.

This code is copyrighted by Ghent University – imec and released under the MIT license.