scrape-it

A Node.js scraper for humans.

Scraping
IonicaBizau/scrape-itionicabizau.net/blog/30-how-to-write-a-web-scraper-in-node-jsscrape-it

README









scrape-it











scrape-it


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A Node.js scraper for humans.







Want to save time or not using Node.js? Try our hosted API.












:cloud: Installation


  1. ```sh
  2. # Using npm
  3. npm install --save scrape-it

  5. # Using yarn
  6. yarn add scrape-it
  7. ```


:bulb: ProTip: You can install the cli version of this module by runningnpm install --global scrape-it-cli (or yarn global add scrape-it-cli).







FAQ



Here are some frequent questions and their answers.

1. How to parse scrape pages?



scrape-it has only a simple request module for making requests. That means you cannot directly parse ajax pages with it, but in general you will have those scenarios:


1. The ajax response is in JSON format. In this case, you can make the request directly, without needing a scraping library.
2. The ajax response gives you HTML back. Instead of calling the main website (e.g. example.com), pass to scrape-it the ajax url (e.g. example.com/api/that-endpoint) and you will you will be able to parse the response
3. The ajax request is so complicated that you don't want to reverse-engineer it. In this case, use a headless browser (e.g. Google Chrome, Electron, PhantomJS) to load the content and then use the .scrapeHTML method from scrape it once you get the HTML loaded on the page.

2. Crawling



There is no fancy way to crawl pages with scrape-it. For simple scenarios, you can parse the list of urls from the initial page and then, using Promises, parse each page. Also, you can use a different crawler to download the website and then use the .scrapeHTML method to scrape the local files.

3. Local files



Use the .scrapeHTML to parse the HTML read from the local files using fs.readFile.








:clipboard: Example




  1. ``` js
  2. const scrapeIt = require("scrape-it")

  4. // Promise interface
  5. scrapeIt("https://ionicabizau.net", {
  6.     title: ".header h1"
  7.   , desc: ".header h2"
  8.   , avatar: {
  9.         selector: ".header img"
  10.       , attr: "src"
  11.     }
  12. }).then(({ data, response }) => {
  13.     console.log(`Status Code: ${response.statusCode}`)
  14.     console.log(data)
  15. })

  17. // Callback interface
  18. scrapeIt("https://ionicabizau.net", {
  19.     // Fetch the articles
  20.     articles: {
  21.         listItem: ".article"
  22.       , data: {

  24.             // Get the article date and convert it into a Date object
  25.             createdAt: {
  26.                 selector: ".date"
  27.               , convert: x => new Date(x)
  28.             }

  30.             // Get the title
  31.           , title: "a.article-title"

  33.             // Nested list
  34.           , tags: {
  35.                 listItem: ".tags > span"
  36.             }

  38.             // Get the content
  39.           , content: {
  40.                 selector: ".article-content"
  41.               , how: "html"
  42.             }

  44.             // Get attribute value of root listItem by omitting the selector
  45.           , classes: {
  46.                 attr: "class"
  47.             }
  48.         }
  49.     }

  51.     // Fetch the blog pages
  52.   , pages: {
  53.         listItem: "li.page"
  54.       , name: "pages"
  55.       , data: {
  56.             title: "a"
  57.           , url: {
  58.                 selector: "a"
  59.               , attr: "href"
  60.             }
  61.         }
  62.     }

  64.     // Fetch some other data from the page
  65.   , title: ".header h1"
  66.   , desc: ".header h2"
  67.   , avatar: {
  68.         selector: ".header img"
  69.       , attr: "src"
  70.     }
  71. }, (err, { data }) => {
  72.     console.log(err || data)
  73. })
  74. // { articles:
  75. //    [ { createdAt: Mon Mar 14 2016 00:00:00 GMT+0200 (EET),
  76. //        title: 'Pi Day, Raspberry Pi and Command Line',
  77. //        tags: [Object],
  78. //        content: '

    Everyone knows (or should know)...a" alt="">

    \n',
  79. //        classes: [Object] },
  80. //      { createdAt: Thu Feb 18 2016 00:00:00 GMT+0200 (EET),
  81. //        title: 'How I ported Memory Blocks to modern web',
  82. //        tags: [Object],
  83. //        content: '

    Playing computer games is a lot of fun. ...',

  84. //        classes: [Object] },
  85. //      { createdAt: Mon Nov 02 2015 00:00:00 GMT+0200 (EET),
  86. //        title: 'How to convert JSON to Markdown using json2md',
  87. //        tags: [Object],
  88. //        content: '

    I love and ...',

  89. //        classes: [Object] } ],
  90. //   pages:
  91. //    [ { title: 'Blog', url: '/' },
  92. //      { title: 'About', url: '/about' },
  93. //      { title: 'FAQ', url: '/faq' },
  94. //      { title: 'Training', url: '/training' },
  95. //      { title: 'Contact', url: '/contact' } ],
  96. //   title: 'Ionică Bizău',
  97. //   desc: 'Web Developer,  Linux geek and  Musician',
  98. //   avatar: '/images/logo.png' }
  99. ```











:question: Get Help


There are few ways to get help:



1. Please post questions on Stack Overflow. You can open issues with questions, as long you add a link to your Stack Overflow question.
2. For bug reports and feature requests, open issues. :bug:
3. For direct and quick help, you can use Codementor. :rocket:





:memo: Documentation



scrapeIt(url, opts, cb)

A scraping module for humans.

Params


- String|Object url: The page url or request options.
- Object opts: The options passed to scrapeHTML method.
- Function cb: The callback function.

Return

- Promise A promise object resolving with:
  - data (Object): The scraped data.
  - $ (Function): The Cheeerio function. This may be handy to do some other manipulation on the DOM, if needed.
  - response (Object): The response object.
  - body (String): The raw body as a string.

scrapeIt.scrapeHTML($, opts)

Scrapes the data in the provided element.

For the format of the selector, please refer to the Selectors section of the Cheerio library

Params


- Cheerio $: The input element.
- Object opts: An object containing the scraping information.
  If you want to scrape a list, you have to use the listItem selector:

   - listItem (String): The list item selector.
   - data (Object): The fields to include in the list objects:
- `` (Object|String): The selector or an object containing:
         - selector (String): The selector.
         - convert (Function): An optional function to change the value.
         - how (Function|String): A function or function name to access the
           value.
         - attr (String): If provided, the value will be taken based on
           the attribute name.
         - trim (Boolean): If false, the value will not be trimmed
           (default: true).
         - closest (String): If provided, returns the first ancestor of
           the given element.
         - eq (Number): If provided, it will select the nth element.
         - texteq (Number): If provided, it will select the nth direct text child.
           Deep text child selection is not possible yet.
           Overwrites the how key.
         - listItem (Object): An object, keeping the recursive schema of
           the listItem object. This can be used to create nested lists.

  Example:
  1. ``` js
  2.   {
  3.      articles: {
  4.          listItem: ".article"
  5.        , data: {
  6.              createdAt: {
  7.                  selector: ".date"
  8.                , convert: x => new Date(x)
  9.              }
  10.            , title: "a.article-title"
  11.            , tags: {
  12.                  listItem: ".tags > span"
  13.              }
  14.            , content: {
  15.                  selector: ".article-content"
  16.                , how: "html"
  17.              }
  18.            , traverseOtherNode: {
  19.                  selector: ".upperNode"
  20.                , closest: "div"
  21.                , convert: x => x.length
  22.              }
  23.          }
  24.      }
  25.   }
  26. ```

  If you want to collect specific data from the page, just use the same
  schema used for the data field.

  Example:
  1. ``` js
  2.   {
  3.        title: ".header h1"
  4.      , desc: ".header h2"
  5.      , avatar: {
  6.            selector: ".header img"
  7.          , attr: "src"
  8.        }
  9.   }
  10. ```

Return

- Object The scraped data.














:yum: How to contribute

Have an idea? Found a bug? See [how to contribute][contributing].


:sparkling_heart: Support my projects

I open-source almost everything I can, and I try to reply to everyone needing help using these projects. Obviously,
this takes time. You can integrate and use these projects in your applications for free! You can even change the source code and redistribute (even resell it).

However, if you get some profit from this or just want to encourage me to continue creating stuff, there are few ways you can do it:


- Starring and sharing the projects you like :rocket:
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Thanks! :heart:
















:dizzy: Where is this library used?

If you are using this library in one of your projects, add it in this list. :sparkles:

- @web-master/node-web-scraper
- proxylist
- mit-ocw-scraper
- beervana-scraper
- cnn-market
- bandcamp-scraper
- @tryghost/mg-webscraper
- blockchain-notifier
- dncli
- degusta-scrapper
- trump-cabinet-picks
- cevo-lookup
- camaleon
- scrape-vinmonopolet
- do-fn
- university-news-notifier
- selfrefactor
- parn
- picarto-lib
- mix-dl
- jishon
- sahibinden
- sahibindenServer
- sgdq-collector
- ubersetzung
- ui-studentsearch
- paklek-cli
- egg-crawler
- @thetrg/gibson
- jobs-fetcher
- fmgo-marketdata
- rayko-tools
- leximaven
- codinglove-scraper
- vandalen.rhyme.js
- uniwue-lernplaetze-scraper
- spon-market
- macoolka-net-scrape
- gatsby-source-bandcamp
- salesforcerelease-parser
- yu-ncov-scrape-dxy
- rs-api
- startpage-quick-search
- helyesiras
- covidau
- 3abn
- scrape-it-cli
- codementor
- u-pull-it-ne-parts-finder
- blankningsregistret
- scrapos-worker
- @ben-wormald/bandcamp-scraper
- bible-scraper
- flamescraper
- fa.js
- growapi
- node-red-contrib-scrape-it
- carirs
- steam-workshop-scraper
- macoolka-network
- apixpress











:scroll: License


[MIT][license] © [Ionică Bizău][website]






[license]: /LICENSE
[website]: https://ionicabizau.net
[contributing]: /CONTRIBUTING.md
[docs]: /DOCUMENTATION.md
[badge_patreon]: https://ionicabizau.github.io/badges/patreon.svg
[badge_amazon]: https://ionicabizau.github.io/badges/amazon.svg
[badge_paypal]: https://ionicabizau.github.io/badges/paypal.svg
[badge_paypal_donate]: https://ionicabizau.github.io/badges/paypal_donate.svg
[patreon]: https://www.patreon.com/ionicabizau
[amazon]: http://amzn.eu/hRo9sIZ
[paypal-donations]: https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=RVXDDLKKLQRJW