Null Pointer Micromanagement

    web-auto-extractor

    1.0.17 • Public • Published

    Web Auto Extractor

    Build Status

    Parse semantically structured information from any HTML webpage.

    Supported formats:-

    • Encodings that support Schema.org vocabularies:-
      • Microdata
      • RDFa-lite
      • JSON-LD
    • Random Meta tags

    Popularly, many websites mark up their webpages with Schema.org vocabularies for better SEO. This library helps you parse that information to JSON.

    Demo it on tonicdev

    Installation

    npm install web-auto-extractor

    Usage

    // IF CommonJS
    var WAE = require('web-auto-extractor').default
    // IF ES6
    import WAE from 'web-auto-extractor'
     
    var parsed = WAE().parse(sampleHTML)
     

    Let's use the following text as the sampleHTML in our example. It uses Schema.org vocabularies to structure a Product information and is encoded in microdata format.

    Input

    <div itemscope itemtype="http://schema.org/Product">
      <span itemprop="brand">ACME</span>
      <span itemprop="name">Executive Anvil</span>
      <img itemprop="image" src="anvil_executive.jpg" alt="Executive Anvil logo" />
      <span itemprop="description">Sleeker than ACME's Classic Anvil, the
        Executive Anvil is perfect for the business traveler
        looking for something to drop from a height.
      </span>
      Product #: <span itemprop="mpn">925872</span>
      <span itemprop="aggregateRating" itemscope itemtype="http://schema.org/AggregateRating">
        <span itemprop="ratingValue">4.4</span> stars, based on <span itemprop="reviewCount">89
          </span> reviews
      </span>
     
      <span itemprop="offers" itemscope itemtype="http://schema.org/Offer">
        Regular price: $179.99
        <meta itemprop="priceCurrency" content="USD" />
        $<span itemprop="price">119.99</span>
        (Sale ends <time itemprop="priceValidUntil" datetime="2020-11-05">
          5 November!</time>)
        Available from: <span itemprop="seller" itemscope itemtype="http://schema.org/Organization">
                          <span itemprop="name">Executive Objects</span>
                        </span>
        Condition: <link itemprop="itemCondition" href="http://schema.org/UsedCondition"/>Previously owned,
          in excellent condition
        <link itemprop="availability" href="http://schema.org/InStock"/>In stock! Order now!</span>
      </span>
    </div>

    Output

    Our parsed object should look like -

    {
      "microdata": {
        "Product": [
          {
            "@context": "http://schema.org/",
            "@type": "Product",
            "brand": "ACME",
            "name": "Executive Anvil",
            "image": "anvil_executive.jpg",
            "description": "Sleeker than ACME's Classic Anvil, the\n    Executive Anvil is perfect for the business traveler\n    looking for something to drop from a height.",
            "mpn": "925872",
            "aggregateRating": {
              "@context": "http://schema.org/",
              "@type": "AggregateRating",
              "ratingValue": "4.4",
              "reviewCount": "89"
            },
            "offers": {
              "@context": "http://schema.org/",
              "@type": "Offer",
              "priceCurrency": "USD",
              "price": "119.99",
              "priceValidUntil": "5 November!",
              "seller": {
                "@context": "http://schema.org/",
                "@type": "Organization",
                "name": "Executive Objects"
              },
              "itemCondition": "http://schema.org/UsedCondition",
              "availability": "http://schema.org/InStock"
            }
          }
        ]
      },
      "rdfa": {},
      "jsonld": {},
      "metatags": {
        "priceCurrency": [
          "USD",
          "USD"
        ]
      }
    }

    The parsed object includes four objects - microdata, rdfa, jsonld and metatags. Since the above HTML does not have any information encoded in rdfa and jsonld, those two objects are empty.

    Caveat

    I wouldn't call it a caveat but rather the parser is strict by design. It might not parse like expected if the HTML isn't encoded correctly, so one might assume the parser is broken.

    For example, take the following HTML snippet.

    <div itemscope itemtype="http://schema.org/Movie">
      <h1 itemprop="name">Ghostbusters</h1>
      <div itemprop="productionCompany" itemscope itemtype="http://schema.org/Organization">Black Rhino</div>
      <div itemprop="countryOfOrigin" itemscope itemtype="http://schema.org/Country">
        Country: <span itemprop="name" content="USA">United States</span><p>
      </div>
    </div>

    The problem here is the itemprop - productionCompany which is of itemtype - Organization doesn't have any itemprop as its children, in this case - name.

    The parser assumes every itemtype contains an itemprop, or every typeof contains a property in case of rdfa. So the "Black Rhino" information is lost.

    It'll be nice to fix this by having a non-strict mode for parsing this information. PRs are welcome.

    License

    MIT

    Install

    npm i web-auto-extractor

    DownloadsWeekly Downloads

    4,248

    Version

    1.0.17

    License

    MIT

    Last publish

    Collaborators

    • vasanthgopal