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('@jsreport/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) => {
        for (const row of table.rows) {
          await 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('@jsreport/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('@jsreport/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) => {
        for (const row of table.rows) {
          await 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

Changelog

1.2.1

• update deps to fix audit

1.2.0

• add support for images
• add indentation support (using data-cell-indent on cells)
• add support for page and print related properties (using data-sheet-page-xxx attributes on table)
• add white-space support, and support for rendering cells with newlines

1.1.0

• update minimum nodejs to 22.18
• better error for invalid base xlsx template
• fix support for more colspan/rowspan based layouts

1.0.2

• fix rowspan/colspan based layout not working

1.0.1

• fix regression in table borders for specific colspan layout
• fix xlsx viewer clipping content. generate empty cell (no child <v>) if cell does not have value

1.0.0

• support for vertical text (transform: rotate() to rotate text at certain angles, using together writing-mode and text-orientation)
• border styles now are normalized according to html table border collapsing rules
• first release after integrating it in the jsreport monorepo

License

See license