xgettext-loader.js

let child = require("child_process")
let source_map = require("source-map")
let SourceMapConsumer = source_map.SourceMapConsumer
let path = require("path")
var crypto = require('crypto');

module.exports = function(source, sourceMap) {
  this.cacheable()
  this.async()
  var self = this
  var xgettext = child.spawn("xgettext", [
    "--from-code=UTF-8",
    "--language=JavaScript",
    "--keyword=gettext:1",
    "--keyword=ngettext:1,2",
    "--keyword=pgettext:1c,2",
    "--keyword=npgettext:1c,2,3",
    "--output=-",
    "-"
  ])
  xgettext.stdin.write(source)
  xgettext.stdin.end()


  var po = ""

  xgettext.stdout.on("data", (data) => po = po + data)

  xgettext.on("close", (code) => {
    if (code == 0) {
      if (po.trim() != "") {
        var lines = source.split("\n")
        var filename = path.relative(".", self.resource)
        var consumer = null;
        if (sourceMap) {
          consumer = new SourceMapConsumer(sourceMap)
        }
        po = po.replace(/^#: st[^:]+:([0-9]+)\n(msgid|msgctxt) ([^\n]+)/igm, (_m, line, msgtype, msgid, _o, _s) => {
          line = line * 1

          var actualLine = "?"
          if (consumer) {
            var column = lines[line - 1].indexOf(msgid) + 1
            var result = consumer.originalPositionFor({line, column})
            actualLine = result.line
          }

          return `#: ${filename}:${actualLine}\n${msgtype} ${msgid}`
        })
        po = po.replace("Content-Type: text/plain; charset=CHARSET", "Content-Type: text/plain; charset=utf-8")

        let hash = crypto.createHash('md5').update(source).digest("hex");
        let query = this.resourceQuery.replace("?", "")
        let outPath = path.join("i18n/sources", `${filename}.${hash}.po`)

        self.emitFile(outPath, po, {})
      }
    } else {
      throw `xgettext returned with code ${code}`
    }

    self.callback(null, source)
  })

  xgettext.stderr.on("data", (error) => {
    xgettext.removeAllListeners()
    self.callback(error, source)
  })

  return undefined;
}

Could you help somebody new to this understand how to add the loader to the vue.config.js file?