Tabletojson: Converting Table to JSON objects made easy

Tabletojson attempts to convert local or remote HTML tables into JSON with a very low footprint. Can be passed the markup for a single table as a string, a fragment of HTML or an entire page or just a URL (with an optional callback function; promises also supported).

The response is always an array. Every array entry in the response represents a table found on the page (in same the order they were found in HTML).

As of version 2.0 tabletojson is completely written in typescript.

Incompatible changes

• Version 2 on request.js is not used anymore
• Version >=2.1.0 got is not used anymore and got replaced by node internal fetch. more information here...
• Switched from commonjs to module system. Bumped version to 3.0.0
• Providing a "hybrid" library to cope with the needs of both esm and commonjs. Bumped version to 4.0.1.

Conversion from version 1.+ to 2.x

• Require must be changed from const tabletojson = require('../lib/tabletojson'); to either const tabletojson = require('../lib/tabletojson').Tabletojson; or const {Tabletojson: tabletojson} = require('../lib/tabletojson');
• Replace request options by fetch options. More information here...

Conversion from version 2.0.1 to 3.x

• Tabletojson now uses esm. Use import {Tabletojson as tabletojson} from 'tabletojson'; or import {tabletojson} from 'tabletojson';
• Added lowercase import import {tabletojson} from 'tabletojson';
• If you are using Node 18 execute examples by calling:

npm run build:examples
cd dist/examples
node --experimental-vm-modules --experimental-specifier-resolution=node example-1.js --prefix=dist/examples

Basic usage

Install via npm

npm install tabletojson

esm

import {tabletojson} from 'tabletojson';
tabletojson.convertUrl('https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes', function (tablesAsJson) {
  console.log(tablesAsJson[1]);
});

commonjs

const {tabletojson} = require('tabletojson');
tabletojson.convertUrl('https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes', function (tablesAsJson) {
  console.log(tablesAsJson[1]);
});

Remote (convertUrl)

// example-1.ts
import {tabletojson} from 'tabletojson';
tabletojson.convertUrl('https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes', function (tablesAsJson) {
    console.log(tablesAsJson[1]);
});

Local (convert)

Have a look in the examples.

// example-6.ts
import {tabletojson} from 'tabletojson';
import * as fs from 'fs';
import * as path from 'path';
const html = fs.readFileSync(path.resolve(process.cwd(), '../../test/tables.html'), {
  encoding: 'utf-8',
});
const converted = tabletojson.convert(html);
console.log(converted);

Duplicate column headings

If there are duplicate column headings, subsequent headings are suffixed with a count:

[{
  PLACE: 'abc', VALUE: '1',
  PLACE_2: 'def', VALUE_2: '2',
}]

Tables with rowspan

Having tables with rowspan, the content of the spawned cell must be available in the respective object.

[{
  PARENT: 'Marry', CHILD: 'Tom', AGE, '3',
  PARENT: 'Marry', CHILD: 'Steve', AGE, '12',
  PARENT: 'Marry', CHILD: 'Sue', AGE, '15'
}]

Tables with complex rowspan

Having tables with complex rowspans, the content of the spawned cell must be available in the respective object.

[{
  PARENT: 'Marry', CHILD: 'Sue', AGE, '15'
  PARENT: 'Marry', CHILD: 'Steve', AGE, '12',
  PARENT: 'Marry', CHILD: 'Tom', AGE, '3',
  PARENT: 'Taylor', CHILD: 'Tom', AGE, '3',
  PARENT: 'Taylor', CHILD: 'Peter', AGE, '17'
}]

Tables with headings in the first column

If a table contains headings in the first column you might get an unexpected result, but you can pass a second argument with options with { useFirstRowForHeadings: true } to have it treat the first column as it would any other cell.

tabletojson.convertUrl(
  'https://www.timeanddate.com/holidays/ireland/2017',
  { useFirstRowForHeadings: true },
  function(tablesAsJson) {
    console.log(tablesAsJson);
  }
);

Tables with HTML

The following options are true by default, which converts all values to plain text to give you an easier more readable object to work with:

• stripHtmlFromHeadings
• stripHtmlFromCells

If your table contains HTML you want to parse (for example for links) you can set stripHtmlFromCells to false to treat it as raw text.

tabletojson.convertUrl(
  'https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes',
  { stripHtmlFromCells: false },
  function(tablesAsJson) {
    //Print out the 1st row from the 2nd table on the above webpage as JSON
    console.log(tablesAsJson[1][0]);
  }
);

Note: This doesn't work with nested tables, which it will still try to parse.

You probably don't need to set stripHtmlFromHeadings to false (and setting it to false can make the results hard to parse), but if you do you can also set both at the same time by setting stripHtml to false.

Options

fetchOptions (only convertUrl)

Tabletojson is using fetch api which is available in node from version 17.5.0 onwards to fetch remote HTML pages. See mdn web docs on fetch for more information. The usage of Tabletojson should now be the same in node as in browsers. So if you need to get data from a remote server you can call tabletojson.convertUrl and pass any fetch-options (proxy, headers,...) by adding a RequestInit object to the options passed to convertUrl. For more information on how to configure request please have a look at Browser Syntax or Node fetch

tabletojson.convertUrl('https://www.timeanddate.com/holidays/ireland/2017', {
    useFirstRowForHeadings: true,
    fetchOptions: {
        ...
    }
});

stripHtmlFromHeadings

Strip any HTML from heading cells. Default is true.

KEY | <b>VALUE</b>
----|-------------
abc |            1
dev |            2

// Example output with stripHtmlFromHeadings:true
[
    {
        KEY: 'abc', VALUE: '1'
    },
    {
        KEY: 'dev', VALUE: '2'
    }
]
// Example output with stripHtmlFromHeadings:false
[
    {
        KEY: 'abc', '<b>VALUE</b>': '1'
    },
    {
        KEY: 'dev', '<b>VALUE</b>': '2'
    }
]

stripHtmlFromCells

Strip any HTML from tableBody cells. Default is true.

KEY |    VALUE
----|---------
abc | <i>1</i>
dev | <i>2</i>

// Example output with stripHtmlFromHeadings:true
[
    {
        KEY: 'abc', VALUE: '1'
    },
    {
        KEY: 'dev', VALUE: '2'
    }
]
// Example output with stripHtmlFromHeadings:false
[
    {
        KEY: 'abc', 'VALUE': '<i>1</i>'
    },
    {
        KEY: 'dev', 'VALUE': '<i>2</i>'
    }
]

forceIndexAsNumber

Instead of using column text (that sometime re-order the data), force an index as a number (string number).

// Some JSON (Other rows)
{
  "0": "",
  "1": "Ａ会",
  "2": "Ｂ会",
  "3": "Ｃ会",
  "4": "Something",
  "5": "Else",
  "6": ""
}
// Some JSON (Other rows)

countDuplicateHeadings

Default is true. If set to false, duplicate headings will not get a trailing number. The value of the field will be the last value found in the table row:

// Example output with countDuplicateHeadings:false
[
    {
        PLACE: 'def', VALUE: '2'
    },
    {
        PLACE: 'jkl', VALUE: '4'
    }
]

ignoreColumns

Array of indexes to be ignored, starting with 0. Default is 'null/undefined'.

// Example output with ignoreColumns: [2, 3]
[
    {
        NAME: 'Mel', PLACE: '1', AGE: '23'
    },
    {
        NAME: 'Tom', PLACE: '2', AGE: '54'
    },
    {
        NAME: 'Bill', PLACE: '3', AGE: '31'
    }
]

onlyColumns

Array of indexes that are taken, starting with 0. Default is 'null/undefined'. If given, this option overrides ignoreColumns.

// Example output with onlyColumns: [0, 4]
[
    {
        NAME: 'Mel', AGE: '23'
    },
    {
        NAME: 'Tom', AGE: '54'
    },
    {
        NAME: 'Bill', AGE: '31'
    }
]

ignoreHiddenRows

Indicates if hidden rows (display:none) are ignored. Default is true:

• Cat | 4 | 4 | W | 2*

// Example output with ignoreHiddenRows:true
[
    {
        NAME: 'Mel', PLACE: '1', WEIGHT: '58', SEX: 'W', AGE: '23'
    },
    {
        NAME: 'Tom', PLACE: '2', WEIGHT: '78', SEX: 'M', AGE: '54'
    },
    {
        NAME: 'Bill', PLACE: '3', WEIGHT: '92', SEX: 'M', AGE: '31'
    }
]
// Example output with ignoreHiddenRows:false
[
    {
        NAME: 'Mel', PLACE: '1', WEIGHT: '58', SEX: 'W', AGE: '23'
    },
    {
        NAME: 'Tom', PLACE: '2', WEIGHT: '78', SEX: 'M', AGE: '54'
    },
    {
        NAME: 'Bill', PLACE: '3', WEIGHT: '92', SEX: 'M', AGE: '31'
    }
    },
    {
        NAME: 'Cat', PLACE: '4', WEIGHT: '4', SEX: 'W', AGE: '2'
    }
]

headings

Array of Strings to be used as headings. Default is null/undefined.

If more headings are given than columns exist the overcounting ones will be ignored. If less headings are given than existing values the overcounting values are ignored.

• Cat | 4 | 4 | W | 2*

// Example output with headings: ['A','B','C','D','E']
[
    {
        A: 'Mel', B: '1', C: '58', D: 'W', E: '23'
    },
    {
        A: 'Tom', B: '2', C: '78', D: 'M', E: '54'
    },
    {
        A: 'Bill', B: '3', C: '92', D: 'M', E: '31'
    }
]
// Example output with headings: ['A','B','C']
[
    {
        A: 'Mel', B: '1', C: '58'
    },
    {
        A: 'Tom', B: '2', C: '78'
    },
    {
        A: 'Bill', B: '3', C: '92'
    }
]
// Example output with headings: ['A','B','C','D','E','F','G','H']
[
    {
        A: 'Mel', B: '1', C: '58', D: 'W', E: '23'
    },
    {
        A: 'Tom', B: '2', C: '78', D: 'M', E: '54'
    },
    {
        A: 'Bill', B: '3', C: '92', D: 'M', E: '31'
    }
]
// Example output with headings: ['A','B','C'] && ignoreColumns: [2, 3]
[
    {
        A: 'Mel', B: 'W', C: '23'
    },
    {
        A: 'Tom', B: 'M', C: '54'
    },
    {
        A: 'Bill', B: 'M', C: '31'
    }
]

limitrows

Number of rows to which the resulting object should be limited to. Default is null/undefined.

Huge Table (see test/tables.html)

Example output with limitrows: 5

[ { 'Roleplayer Number': '0',
        Name: 'Raife Parkinson',
        'Text to say': 're dolor in hendrerit in vulputate ve' },
      { 'Roleplayer Number': '1',
        Name: 'Hazel Schultz',
        'Text to say': 'usto duo dolores et ea rebum. Ste' },
      { 'Roleplayer Number': '2',
        Name: 'Montana Delgado',
        'Text to say': 'psum dolor sit amet. Lorem ipsum dolor sit ame' },
      { 'Roleplayer Number': '3',
        Name: 'Dianne Mcbride',
        'Text to say': 'olor sit amet. Lorem ipsum' },
      { 'Roleplayer Number': '4',
        Name: 'Xena Lynch',
        'Text to say': 'us est Lorem ipsum dol' } ]

containsClasses

Array of classes to find a specific table using this class. Default is null/ undefined.

Known issues and limitations

This module only supports parsing basic tables with a simple horizontal set of <th></th> headings and corresponding <td></td> cells.

It can give useless or weird results on tables that have complex structures (such as nested tables) or multiple headers (such as on both X and Y axis).

You'll need to handle things like work out which tables to parse and (in most cases) clean up the data. You might want to combine it it with modules like json2csv or CsvToMarkdownTable.

You might want to use it with a module like 'cheerio' if you want to parse specific tables identified by id or class (i.e. select them with cheerio and pass the HTML of them as a string).

Example usages

// Convert an HTML text into an array of all the tables on the page
import {tabletojson} from 'tabletojson';
const tablesAsJson = tabletojson.convert(html);
const firstTableAsJson = tablesAsJson[0];
const secondTableAsJson = tablesAsJson[1];
...

// Fetch a URL and parse all it's tables into JSON, using a callback
import {tabletojson} from 'tabletojson';
tabletojson.convertUrl('https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes', function (tablesAsJson) {
  console.log(tablesAsJson[1]);
});

// Fetch a URL and parse all it's tables into JSON, using promises
import {tabletojson} from 'tabletojson';
const url = 'http://en.wikipedia.org/wiki/List_of_countries_by_credit_rating';
tabletojson.convertUrl(url)
.then(function(tablesAsJson) {
  const standardAndPoorRatings = tablesAsJson[1];
  const fitchRatings = tablesAsJson[2];
});

// Fetch a table from Wikipedia and combine with json2csv to convert to CSV
import {tabletojson} from 'tabletojson';
import {Parser} from 'json2csv';
const url = 'http://en.wikipedia.org/wiki/List_of_countries_by_credit_rating';
tabletojson.convertUrl(url).then(function (tablesAsJson) {
  const fitchRatings = tablesAsJson[2];
  const json2csvParser = new Parser({
    fields: ['Country/Region', 'Outlook'],
  });
  const csv = json2csvParser.parse(fitchRatings);
  console.log(csv);
  /* Example output
        "Country/Region","Outlook"
        "Abu Dhabi, UAE","Stable"
        "Albania","Stable"
        "Andorra","Negative"
        "Angola","Stable"
        "Argentina","Negative"
        "Aruba","Stable"
        "Australia","Stable"
        "Austria","Negative"
        "Azerbaijan","Positive"
        ...
      */
});

Limitations

• Tables needs to be "well formatted" to be convertable.
• Tables in tables are not processed.

Contributing

Improvements, fixes and suggestions are welcome.

You can find basic tests in the test folder. The library has been implemented to be used straight forward way. Nonetheless there are some edge cases that need to be tested and I would like to ask for support here. Feel free to fork and create PRs here. Every bit of help is appreciated.

For more usage examples have a look in the examples folder that shows usage and would be a good start.

If you submit a pull request, please add an example for your use case, so I can understand what you want it to do (as I want to get around to writing tests for this and want to understand the sort of use cases people have).

Thanks

June 2018 - Very special thanks to the originator of the library, Iain Collins (@iaincollins). Without his investigation in website grasping and mastering cheerio this lib would have not been where it is right now. Also I would personally like to say "Thank you" for your trust in passing me the ownership. Marius (@maugenst)

Additional thanks to

• @roryok
• Max Thyen (@maxthyen)
• Thor Jacobsen (@twjacobsen)
• Michael Keller (@mhkeller)
• Jesús Leganés-Combarro (@piranna)
• João Otávio Ferreira Barbosa (@joaobarbosa)

for improvements and bug fixes.