html-to-xlsx

node.js html to xlsx transformation

Transformation only supports html table and several basic style properties. No images or charts are currently supported.

Usage

const util = require('util')
const fs = require('fs')
const conversionFactory = require('html-to-xlsx')
const puppeteer = require('puppeteer')
const chromeEval = require('chrome-page-eval')({ puppeteer })
const writeFileAsync = util.promisify(fs.writeFile)

const conversion = conversionFactory({
  extract: async ({ html, ...restOptions }) => {
    const tmpHtmlPath = path.join('/path/to/temp', 'input.html')

    await writeFileAsync(tmpHtmlPath, html)

    const result = await chromeEval({
      ...restOptions,
      html: tmpHtmlPath,
      scriptFn: conversionFactory.getScriptFn()
    })

    const tables = Array.isArray(result) ? result : [result]

    return tables.map((table) => ({
      name: table.name,
      getRows: async (rowCb) => {
        table.rows.forEach((row) => {
          rowCb(row)
        })
      },
      rowsCount: table.rows.length
    }))
  }
})

async function run () {
  const stream = await conversion(`<table><tr><td>cell value</td></tr></table>`)

  stream.pipe(fs.createWriteStream('/path/to/output.xlsx'))
}

run()

Supported properties

background-color - cell background color
color - cell foreground color
border-left-style - as well as positions will be transformed into excel cells borders
text-align - text horizontal align in the excel cell
vertical-align - vertical align in the excel cell
width - the excel column will get the highest width, it can be little bit inaccurate because of pixel to excel points conversion
height - the excel row will get the highest height
font-size - font size
colspan - numeric value that merges current column with columns to the right
rowspan - numeric value that merges current row with rows below.
overflow - the excel cell will have text wrap enabled if this is set to scroll or auto.

Constructor options

const conversionFactory = require('html-to-xlsx')
const puppeteer = require('puppeteer')
const chromeEval = require('chrome-page-eval')({ puppeteer })
const conversion = conversionFactory({ /*[constructor options here]*/})

extract function [required] - a function that receives some input (an html file path and a script) and should return some data after been evaluated the html passed. the input that the function receives is:

{
  html: <file path to a html file>,
  scriptFn: <string that contains a javascript function to evaluate in the html>,
  timeout: <time in ms to wait for the function to complete, the function should use this value to abort any execution when the time has passed>,
  /*options passed to `conversion` will be propagated to the input of this function too*/
}

tmpDir string - the directory path that the module is going to use to save temporary files needed during the conversion. defaults to require('os').tmpdir()
timeout number - time in ms to wait for the conversion to complete, when the timeout is reached the conversion is cancelled. defaults to 10000

Conversion options

const fs = require('fs')
const conversionFactory = require('html-to-xlsx')
const puppeteer = require('puppeteer')
const chromeEval = require('chrome-page-eval')({ puppeteer })
const conversion = conversionFactory({
  extract: async ({ html, ...restOptions }) => {
    const tmpHtmlPath = path.join('/path/to/temp', 'input.html')

    await writeFileAsync(tmpHtmlPath, html)

    const result = await chromeEval({
      ...restOptions,
      html: tmpHtmlPath,
      scriptFn: conversionFactory.getScriptFn()
    })

    const tables = Array.isArray(result) ? result : [result]

    return tables.map((table) => ({
      name: table.name,
      getRows: async (rowCb) => {
        table.rows.forEach((row) => {
          rowCb(row)
        })
      },
      rowsCount: table.rows.length
    }))
  }
})

async function main () {
  const stream = await conversion(/* html */, /* extract options */)
}

main()

html string - the html source that will be transformed to an xlsx, the html should contain a table element
extractOptions object - additional options to pass to the specified extract function