open_graph.js

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/**
 * Product extraction via Open Graph tags.
 */

import {parsePrice} from 'commerce/extraction/utils';

const OPEN_GRAPH_PROPERTY_VALUES = {
  title: 'og:title',
  image: 'og:image',
  price: 'og:price:amount',
};

/** How product information is extracted depends on the feature */
const FEATURE_DEFAULTS = {
  getValueFromElement(element) {
    return element.getAttribute('content');
  },
};
const PRODUCT_FEATURES = {
  image: {
    ...FEATURE_DEFAULTS,
  },
  title: {
    ...FEATURE_DEFAULTS,
  },
  price: {
    ...FEATURE_DEFAULTS,
    getValueFromElement(element) {
      return parsePrice([element.getAttribute('content')]);
    },
  },
};

/**
 * Returns any product information available on the page from Open Graph <meta>
 * tags.
 */
export default function extractProduct() {
  const extractedProduct = {};
  for (const [feature, propertyValue] of Object.entries(OPEN_GRAPH_PROPERTY_VALUES)) {
    const metaEle = document.querySelector(`meta[property='${propertyValue}']`);

    // Fail early if any required tags aren't found.
    if (!metaEle) {
      return null;
    }

    extractedProduct[feature] = PRODUCT_FEATURES[feature].getValueFromElement(metaEle);
  }

  return extractedProduct;
}