Fix #84: Improve fallback extraction

src/extraction/fallback_extraction.js

@@ -10,7 +10,8 @@
 * Features: title, image, price
 */
 
-import extractionData from 'commerce/extraction/product_extraction_data.json';
+import extractionData from 'commerce/extraction/fallback_extraction_selectors';
+
 
 const OPEN_GRAPH_PROPERTY_VALUES = {
   title: 'og:title',
@@ -22,67 +23,53 @@ const OPEN_GRAPH_PROPERTY_VALUES = {
  * Returns any extraction data found for the vendor based on the URL
  * for the page.
  */
-function getProductAttributeInfo() {
+function getFeatureInfo() {
   const hostname = new URL(window.location.href).host;
-  for (const [vendor, attributeInfo] of Object.entries(extractionData)) {
-    if (hostname.includes(vendor)) {
-      return attributeInfo;
+  for (const siteInfo of extractionData) {
+    for (const domain of siteInfo.domains) {
+      if (hostname.includes(domain)) {
+        return siteInfo.features;
+      }
     }
   }
   return null;
 }
 
-/**
- * Extracts and returns the string value for a given element property or attribute.
- *
- * @param {HTMLElement} element
- * @param {string} extractionProperty
- */
-function extractValueFromElement(element, extractionProperty) {
-  switch (extractionProperty) {
-    case 'content':
-      return element.getAttribute('content');
-    case 'innerText':
-      return element.innerText;
-    case 'src':
-      return element.src;
-    default:
-      throw new Error(`Unrecognized extraction property or attribute '${extractionProperty}'.`);
+function findValue(extractors) {
+  for (const [selector, extractionMethod] of extractors) {
+    const element = document.querySelector(selector);
+    if (element) {
+      const value = extractionMethod(element);
+      if (value) {
+        return value;
+      }
+      // eslint-disable-next-line no-console
+      console.warn('Element found did not return a valid value for the product feature.');
+    }
   }
+  // eslint-disable-next-line no-console
+  console.warn('No elements found with vendor data for the product feature.');
+  return null;
 }
 
 /**
  * Returns any product information available on the page from CSS
  * selectors if they exist, otherwise from Open Graph <meta> tags.
  */
 export default function extractProduct() {
-  const data = {};
-  const attributeInfo = getProductAttributeInfo();
-  if (attributeInfo) {
-    for (const [productAttribute, extractor] of Object.entries(attributeInfo)) {
-      const {selectors, extractUsing} = extractor;
-      for (const selector of selectors) {
-        const element = document.querySelector(selector);
-        if (element) {
-          data[productAttribute] = extractValueFromElement(element, extractUsing);
-          if (data[productAttribute]) {
-            break;
-          } else {
-            throw new Error(`Element found did not return a valid product ${productAttribute}.`);
-          }
-        } else if (selector === selectors[selectors.length - 1]) {
-          // None of the selectors matched an element on the page
-          throw new Error(`No elements found with vendor data for product ${productAttribute}.`);
-        }
-      }
+  const extractedProduct = {};
+  const featureInfo = getFeatureInfo();
+  if (featureInfo) {
+    for (const [feature, extractors] of Object.entries(featureInfo)) {
+      extractedProduct[feature] = findValue(extractors);
     }
   } else {
-    for (const [key, value] of Object.entries(OPEN_GRAPH_PROPERTY_VALUES)) {
-      const metaEle = document.querySelector(`meta[property='${value}']`);
+    for (const [feature, propertyValue] of Object.entries(OPEN_GRAPH_PROPERTY_VALUES)) {
+      const metaEle = document.querySelector(`meta[property='${propertyValue}']`);
       if (metaEle) {
-        data[key] = metaEle.getAttribute('content');
+        extractedProduct[feature] = metaEle.getAttribute('content');
       }
     }
   }
-  return data;
+  return extractedProduct;
 }

src/extraction/fallback_extraction_selectors.js

@@ -0,0 +1,135 @@
+/* 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/. */
+
+import {parsePrice} from 'commerce/extraction/utils';
+
+function inUnits(fn) {
+  return (element) => {
+    const priceString = fn(element);
+    return parsePrice([priceString]);
+  };
+}
+
+function fromProperty(property) {
+  return (element => element[property]);
+}
+
+function fromAttribute(attribute) {
+  return (element => element.getAttribute(attribute));
+}
+
+
+/**
+ * CSS selector data by site, where each selector is paired with a method that
+ * extracts the value from the element returned by that selector.
+ */
+const fallbackExtractionData = [
+  {
+    domains: ['amazon.com', 'www.amazon.com', 'smile.amazon.com'],
+    features: {
+      title: [
+        ['#productTitle', fromProperty('innerText')],
+        ['.product-title', fromProperty('innerText')],
+      ],
+      price: [
+        ['#priceblock_dealprice', inUnits(fromProperty('innerText'))],
+        ['#priceblock_ourprice', inUnits(fromProperty('innerText'))],
+        ['#price_inside_buybox', inUnits(fromProperty('innerText'))],
+        ['#buybox .a-color-price', inUnits(fromProperty('innerText'))],
+        ['input[name="displayedPrice"]', inUnits(fromAttribute('value'))],
+        ['.a-size-large.a-color-price.guild_priceblock_ourprice', inUnits(fromProperty('innerText'))],
+        ['.a-color-price.a-size-medium.a-align-bottom', inUnits(fromProperty('innerText'))],
+        ['.display-price', inUnits(fromProperty('innerText'))],
+        ['.offer-price', inUnits(fromProperty('innerText'))],
+      ],
+      image: [
+        ['#landingImage', fromProperty('src')],
+        ['#imgBlkFront', fromProperty('src')],
+        ['#ebooksImgBlkFront', fromProperty('src')],
+      ],
+    },
+  },
+  {
+    domains: ['bestbuy.com', 'www.bestbuy.com'],
+    features: {
+      title: [
+        ['.sku-title h1', fromProperty('innerText')],
+      ],
+      price: [
+        ['.priceView-hero-price.priceView-purchase-price', inUnits(fromProperty('innerText'))],
+      ],
+      image: [
+        ['img.primary-image', fromProperty('src')],
+      ],
+    },
+  },
+  {
+    domains: ['ebay.com', 'www.ebay.com'],
+    features: {
+      title: [
+        ['#itemTitle', fromProperty('innerText')],
+        ['.product-title', fromProperty('innerText')],
+      ],
+      price: [
+        ['#prcIsum', inUnits(fromProperty('innerText'))],
+        ['#orgPrc', inUnits(fromProperty('innerText'))],
+        ['#mm-saleDscPrc', inUnits(fromProperty('innerText'))],
+        ['.display-price', inUnits(fromProperty('innerText'))],
+      ],
+      image: [
+        ['#icImg', fromProperty('src')],
+        ['.vi-image-gallery__image.vi-image-gallery__image--absolute-center', fromProperty('src')],
+      ],
+    },
+  },
+  {
+    domains: ['homedepot.com', 'www.homedepot.com'],
+    features: {
+      title: [
+        ['h1.product-title__title', fromProperty('innerText')],
+      ],
+      price: [
+        ['#ajaxPrice', inUnits(fromAttribute('content'))],
+        ['#ajaxPriceAlt', inUnits(fromProperty('innerText'))],
+      ],
+      image: [
+        ['#mainImage', fromProperty('src')],
+      ],
+    },
+  },
+  {
+    domains: ['walmart.com', 'www.walmart.com'],
+    features: {
+      title: [
+        ['h1.prod-ProductTitle', fromAttribute('content')],
+        ['h1.prod-ProductTitle', fromProperty('innerText')],
+      ],
+      price: [
+        ['.PriceRange.prod-PriceHero', inUnits(fromProperty('innerText'))],
+        ['.price-group', inUnits(fromAttribute('aria-label'))],
+        ['.price-group', inUnits(fromProperty('innerText'))],
+      ],
+      image: [
+        ['.prod-hero-image-image', fromProperty('src')],
+        ['.prod-hero-image-carousel-image', fromProperty('src')],
+      ],
+    },
+  },
+  {
+    domains: ['mkelly.me', 'www.mkelly.me'],
+    features: {
+      title: [
+        ['#title', fromProperty('innerText')],
+      ],
+      price: [
+        ['#price', inUnits(fromProperty('innerText'))],
+      ],
+      image: [
+        ['img', fromProperty('src')],
+      ],
+    },
+  },
+];
+
+export default fallbackExtractionData;

src/extraction/fathom_extraction.js

@@ -12,7 +12,7 @@
 
 import defaultCoefficients from 'commerce/extraction/fathom_default_coefficients.json';
 import RulesetFactory from 'commerce/extraction/ruleset_factory';
-import {getPriceInSubunits} from 'commerce/extraction/utils';
+import {parsePrice} from 'commerce/extraction/utils';
 
 // Minimum score to be considered the "correct" feature element extracted by Fathom
 const SCORE_THRESHOLD = 4;
@@ -42,7 +42,8 @@ const PRODUCT_FEATURES = {
   price: {
     ...FEATURE_DEFAULTS,
     getValueFromElement(element) {
-      return getPriceInSubunits(element);
+      const tokens = Array.from(element.childNodes).map(node => node.textContent);
+      return parsePrice(tokens);
     },
   },
 };