@rpidanny/pdf2md/lib/models/transformations/line-item/CompactLines.js

A PDF to Markdown Converter

// @flow

const ToLineItemTransformation = require('../ToLineItemTransformation')
const ParseResult = require('../../ParseResult')
const LineItem = require('../../LineItem')
const TextItemLineGrouper = require('../../TextItemLineGrouper')
const LineConverter = require('../../LineConverter')
const BlockType = require('../../markdown/BlockType')
const { REMOVED_ANNOTATION, ADDED_ANNOTATION } = require('../../Annotation')

// gathers text items on the same y line to one line item
module.exports = class CompactLines extends ToLineItemTransformation {
  constructor () {
    super('Compact To Lines')
  }

  transform (parseResult /*: ParseResult */) /*: ParseResult */ {
    const { mostUsedDistance, fontToFormats } = parseResult.globals
    const foundFootnotes = []
    const foundFootnoteLinks = []
    var linkCount = 0
    var formattedWords = 0

    const lineGrouper = new TextItemLineGrouper({
      mostUsedDistance: mostUsedDistance,
    })
    const lineCompactor = new LineConverter(fontToFormats)

    parseResult.pages.forEach(page => {
      if (page.items.length > 0) {
        const lineItems = []
        const textItemsGroupedByLine = lineGrouper.group(page.items)
        textItemsGroupedByLine.forEach(lineTextItems => {
          const lineItem = lineCompactor.compact(lineTextItems)
          if (lineTextItems.length > 1) {
            lineItem.annotation = ADDED_ANNOTATION
            lineTextItems.forEach(item => {
              item.annotation = REMOVED_ANNOTATION
              lineItems.push(new LineItem({
                ...item,
              }))
            })
          }
          if (lineItem.words.length === 0) {
            lineItem.annotation = REMOVED_ANNOTATION
          }
          lineItems.push(lineItem)

          if (lineItem.parsedElements.formattedWords) {
            formattedWords += lineItem.parsedElements.formattedWords
          }
          if (lineItem.parsedElements.containLinks > 0) {
            linkCount++
          }
          if (lineItem.parsedElements.footnoteLinks.length > 0) {
            const footnoteLinks = lineItem.parsedElements.footnoteLinks.map(footnoteLink => ({ footnoteLink, page: page.index + 1 }))
            foundFootnoteLinks.push.apply(foundFootnoteLinks, footnoteLinks)
          }
          if (lineItem.parsedElements.footnotes.length > 0) {
            lineItem.type = BlockType.FOOTNOTES
            const footnotes = lineItem.parsedElements.footnotes.map(footnote => ({ footnote, page: page.index + 1 }))
            foundFootnotes.push.apply(foundFootnotes, footnotes)
          }
        })
        page.items = lineItems
      }
    })

    return new ParseResult({
      ...parseResult,
      messages: [
        'Detected ' + formattedWords + ' formatted words',
        'Found ' + linkCount + ' links',
        'Detected ' + foundFootnoteLinks.length + ' footnotes links',
        'Detected ' + foundFootnotes.length + ' footnotes',
      ],
    })
  }
}