scrapise v0.0.2

Scrapise

Scraper + Promise = Scrapise. A promise based scraping library.

Installation

$ npm install --save scrapise

Documentation

Api

Scrapise requires two arguments, url and schema then returns a promise with the parsed result.

const scrapise = require('scrapise')

const schema = {
  commits: '.numbers-summary .commits .num'
}

scrapise('https://github.com/eremt/scrapise', schema)
  .then(response => {
    console.log(response)
  })
//=> { "commits": "3" }

Schema

The schema defines the shape of the returned object after parsing. Each value is either string, function, array or nested object.

All examples below use the following markup.

<ul>
  <li>
    <a href="https://my-domain.com/commits/2">
      <span class="message">changed something</span>
      <span class="author">John Doe</span>
    </a>
  </li>
  <li>
    <a href="https://my-domain.com/commits/1">
      <span class="message">initial commit</span>
      <span class="author">John Doe</span>
    </a>
  </li>
</ul>

String

The simplest type is a string and will be treated as a CSS selector. It returns the text content of the first match, to get all matches wrap the selector in an array instead.

const schema = {
  last: '.message'
}
//=> {
//     "last": "changed something"
//   }

Function

The function is as expected a callback. It accepts 2 arguments, the cheerio object and a context if it exists. Refer to the cheerio documentation for information on the api.

const schema = {
  links: ($, context) => {
    return $('a').map((i, el) => $(el).attr('href')).get()
  }
}
//=> {
//     "links": [
//       "https://my-domain.com/commits/2",
//       "https://my-domain.com/commits/1"
//     ]
//   }

Array

The array is useful to retrieve lists. The first index is either a string or a schema object, and the second is the context. The context is required when a schema is provided to ensure all fields are grouped correctly.

First lets extract the text using li as the selector:

const schema = {
  list: ['li']
}
//=> {
//     "list": [
//       "changed something\n      John Doe",
//       "initial commit\n      John Doe"
//     ]
//   }

Sometimes that's enough but with our markup it doesn't look very good. If we use schema instead of a selector and the li as context the result is much better:

const commitSchema = {
  message: '.message',
  author: '.author'
}
const schema = {
  list: [commitSchema, 'li']
}
//=> {
//     "list": [
//       {
//         "message": "changed something",
//         "author": "John Doe"
//       },
//       {
//         "message": "initial commit",
//         "author": "John Doe"
//       }
//     ]
//   }

License

MIT