Service to automatically generate specs from various source formats
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Spec Generator

This exposes a service to automatically generate specs from various source formats.



Start the server listening on port 80 by default:

node server

You can specify a port like so:

PORT=3000 node server

Spec Generator has a single endpoint, which is a GET /. This endpoint accepts parameters on its query string. If the call is successful the generated content of the specification is returned.

  • type (required). The type of generator for this content. Currently the only supported value is respec.
  • url (required). The URL of the draft to fetch and generate from.
  • publishDate. The date at which the publication of this draft is supposed to occur.

As a Node.js module

const SPEC_GEN = require('w3c-spec-generator');
const SERVER = SPEC_GEN.start();    // Optional port number (80 by default)
// Now Spec Generator is listening on port 80
SERVER.close();    // To stop the server


If a required parameter is missing or has a value that is not understood, the generator returns a 500 error with a JSON payload the error field of which is the human-readable error message.

If the specific generator encounters a problem a similar error (mostly likely 500) with the same sort of JSON message is returned. Specific generator types can extend this behaviour. The respec generator only returns 500 errors.

Writing generators

Generators are simple to write and new ones can easily be added. Simply add a new one under generators and load it into the genMap near the top of server.js.

Generators must export a generate() method which takes a URL, a set of parameters (from the list of optional ones that the API supports), and a callback to invoke upon completion.

If there is an error, the callback's first argument must be an object with a status field being an HTTP error code and a message field containing the error message. If the generator is successful the first argument is null and the second is the generated content.


The generator for ReSpec requires a running X server; in a headless environment, you will need to run it in connection with a Xvfb instance:

Xvfb :3  &  # (where 3 is the display port)
DISPLAY=:3 node server.js

A sufficient (but perhaps more than necessary) set of packages in a Debian/Ubuntu environment is xvfb x11-xkb-utils xfonts-100dpi xfonts-75dpi xfonts-scalable xfonts-cyrillic x11-apps clang libdbus-1-dev libgtk2.0-dev libnotify-dev libgnome-keyring-dev libgconf2-dev libasound2-dev libcap-dev libcups2-dev libxtst-dev libxss1 libnss3-dev gcc-multilib g++-multilib.