validator-rules

AMP-Toolbox Validator Rules

Queries published AMP Validator rules and extracts information about required markup and attributes for all AMP formats.

Usage

Install via:

$ npm install @ampproject/toolbox-validator-rules

Including the Module

ES Module (Browser)

import validatorRules from '@ampproject/toolbox-validator-rules';

CommonJs (Node)

const validatorRules = require('@ampproject/toolbox-validator-rules');

Using the module

  // Loads the validator rules remotely with default options
  const rules = await validatorRules.fetch();


  // The raw unprocessed rules
  console.log(rules.raw);

  // All tags, combined with their respective attribute lists
  console.log(rules.tags);

  // All extensions
  console.log(rules.extensions);

  // Get all tag names used in AMP for Email
  // The supported formats are AMP, AMP4EMAIL, AMP4ADS and ACTIONS
  const tags = rules.getTagsForFormat('AMP4EMAIL');

  // Display their names
  console.log(tags.map(tag => tag.tagName));

  // Get information about an extension
  const ext = rules.getExtension('AMP4EMAIL', 'amp-carousel');

  // Display supported versions
  console.log(ext.versions);

Format of rules

The rules used closely follow the proto definitions from validator.proto.

Specifically:

• The raw property is unprocessed ValidatorRules, the same format used by https://cdn.ampproject.org/v0/validator.json
• The result of getTagsForFormat and the tags property is a list of TagSpec
• The result of getExtension is ExtensionSpec with the htmlFormat field from TagSpec
• The extensions property a list of ExtensionSpec with the htmlFormat field from TagSpec
• The errors property combines ErrorFormat and ErrorSpecificity

Options

fetch optionally accepts an options object allowing you to customize its behaviour.

The following options are supported:

• noCache: true to always fetch latest rules (by default, subsequent calls to fetch reuse the same result).
• rules: object to use locally specified rules instead of fetching them from the AMP CDN.
• url: override the URL where validator rules are fetched from.
• source: one of 'local' (load rules from local file named "validator.json"), 'remote' (fetch rules from CDN) or 'auto' which is the default (tries looking for the local file first, then tries to fetch from CDN).

Example:

validatorRules.fetch({
  noCache: true,
  source: 'remote'
});