web-auto-extractor
v1.0.17
Published
Automatically extracts structured information from webpages
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Web Auto Extractor
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