print-js/src/js/init.js

A tiny javascript library to help printing from the web.

'use strict'

import Browser from './browser'
import Modal from './modal'
import Pdf from './pdf'
import Html from './html'
import Image from './image'
import Json from './json'

let printTypes = ['pdf', 'html', 'image', 'json']

export default {
  init () {
    let params = {
      printable: null,
      fallbackPrintable: null,
      type: 'pdf',
      header: null,
      headerStyle: 'font-weight: 300;',
      maxWidth: 800,
      font: 'TimesNewRoman',
      font_size: '12pt',
      honorMarginPadding: true,
      honorColor: false,
      properties: null,
      gridHeaderStyle: 'font-weight: bold; padding: 5px; border: 1px solid #dddddd;',
      gridStyle: 'border: 1px solid lightgray; margin-bottom: -1px;',
      showModal: false,
      onLoadingStart: null,
      onLoadingEnd: null,
      modalMessage: 'Retrieving Document...',
      frameId: 'printJS',
      htmlData: '',
      documentTitle: 'Document',
      targetStyle: ['clear', 'display', 'width', 'min-width', 'height', 'min-height', 'max-height'],
      targetStyles: ['border', 'box', 'break', 'text-decoration'],
      ignoreElements: [],
      imageStyle: 'width:100%;',
      repeatTableHeader: true,
      css: null,
      style: null,
      scanStyles: true
    }

    // Check if a printable document or object was supplied
    let args = arguments[0]
    if (args === undefined) throw new Error('printJS expects at least 1 attribute.')

    // Process parameters
    switch (typeof args) {
      case 'string':
        params.printable = encodeURI(args)
        params.fallbackPrintable = params.printable
        params.type = arguments[1] || params.type
        break
      case 'object':
        params.printable = args.printable
        params.fallbackPrintable = typeof args.fallbackPrintable !== 'undefined' ? args.fallbackPrintable : params.printable
        params.type = typeof args.type !== 'undefined' ? args.type : params.type
        params.frameId = typeof args.frameId !== 'undefined' ? args.frameId : params.frameId
        params.header = typeof args.header !== 'undefined' ? args.header : params.header
        params.headerStyle = typeof args.headerStyle !== 'undefined' ? args.headerStyle : params.headerStyle
        params.maxWidth = typeof args.maxWidth !== 'undefined' ? args.maxWidth : params.maxWidth
        params.font = typeof args.font !== 'undefined' ? args.font : params.font
        params.font_size = typeof args.font_size !== 'undefined' ? args.font_size : params.font_size
        params.honorMarginPadding = typeof args.honorMarginPadding !== 'undefined' ? args.honorMarginPadding : params.honorMarginPadding
        params.properties = typeof args.properties !== 'undefined' ? args.properties : params.properties
        params.gridHeaderStyle = typeof args.gridHeaderStyle !== 'undefined' ? args.gridHeaderStyle : params.gridHeaderStyle
        params.gridStyle = typeof args.gridStyle !== 'undefined' ? args.gridStyle : params.gridStyle
        params.showModal = typeof args.showModal !== 'undefined' ? args.showModal : params.showModal
        params.onLoadingStart = typeof args.onLoadingStart !== 'undefined' ? args.onLoadingStart : params.onLoadingStart
        params.onLoadingEnd = typeof args.onLoadingEnd !== 'undefined' ? args.onLoadingEnd : params.onLoadingEnd
        params.modalMessage = typeof args.modalMessage !== 'undefined' ? args.modalMessage : params.modalMessage
        params.documentTitle = typeof args.documentTitle !== 'undefined' ? args.documentTitle : params.documentTitle
        params.targetStyle = typeof args.targetStyle !== 'undefined' ? args.targetStyle : params.targetStyle
        params.targetStyles = typeof args.targetStyles !== 'undefined' ? args.targetStyles : params.targetStyles
        params.ignoreElements = typeof args.ignoreElements !== 'undefined' ? args.ignoreElements : params.ignoreElements
        params.imageStyle = typeof args.imageStyle !== 'undefined' ? args.imageStyle : params.imageStyle
        params.repeatTableHeader = typeof args.repeatTableHeader !== 'undefined' ? args.repeatTableHeader : params.repeatTableHeader
        params.css = typeof args.css !== 'undefined' ? args.css : params.css
        params.style = typeof args.style !== 'undefined' ? args.style : params.style
        params.scanStyles = typeof args.scanStyles !== 'undefined' ? args.scanStyles : params.scanStyles
        break
      default:
        throw new Error('Unexpected argument type! Expected "string" or "object", got ' + typeof args)
    }

    // Validate printable
    if (!params.printable) throw new Error('Missing printable information.')

    // Validate type
    if (!params.type || typeof params.type !== 'string' || printTypes.indexOf(params.type.toLowerCase()) === -1) {
      throw new Error('Invalid print type. Available types are: pdf, html, image and json.')
    }

    // Check if we are showing a feedback message to the user (useful for large files)
    if (params.showModal) Modal.show(params)

    // Check for a print start hook function
    if (params.onLoadingStart) params.onLoadingStart()

    // To prevent duplication and issues, remove any used printFrame from the DOM
    let usedFrame = document.getElementById(params.frameId)

    if (usedFrame) usedFrame.parentNode.removeChild(usedFrame)

    // Create a new iframe or embed element (IE prints blank pdf's if we use iframe)
    let printFrame

    // Create iframe element
    printFrame = document.createElement('iframe')

    // Hide iframe
    printFrame.setAttribute('style', 'visibility: hidden; height: 0; width: 0; position: absolute;')

    // Set iframe element id
    printFrame.setAttribute('id', params.frameId)

    // For non pdf printing, pass an html document string to srcdoc (force onload callback)
    if (params.type !== 'pdf') {
      printFrame.srcdoc = '<html><head><title>' + params.documentTitle + '</title>'

      // Attach css files
      if (params.css !== null) {
        // Add support for single file
        if (!Array.isArray(params.css)) params.css = [params.css]

        // Create link tags for each css file
        params.css.forEach(file => {
          printFrame.srcdoc += '<link rel="stylesheet" href="' + file + '">'
        })
      }

      printFrame.srcdoc += '</head><body></body></html>'
    }

    // Check printable type
    switch (params.type) {
      case 'pdf':
        // Check browser support for pdf and if not supported we will just open the pdf file instead
        if (Browser.isFirefox() || Browser.isEdge() || Browser.isIE()) {
          console.info('PrintJS currently doesn\'t support PDF printing in Firefox, Internet Explorer and Edge.')
          let win = window.open(params.fallbackPrintable, '_blank')
          win.focus()
          // Make sure there is no loading modal opened
          if (params.showModal) Modal.close()
          if (params.onLoadingEnd) params.onLoadingEnd()
        } else {
          Pdf.print(params, printFrame)
        }
        break
      case 'image':
        Image.print(params, printFrame)
        break
      case 'html':
        Html.print(params, printFrame)
        break
      case 'json':
        Json.print(params, printFrame)
        break
    }
  }
}