gallery.js

import * as d3 from 'd3'

/**
 * The gallary organizes the images to be displayed.
 **/
class Gallery {
  /**
   * Construct a new Gallery with the attributes
   *  images          array of image location strings
   *  allowRemote     whether to allow images from other vHosts (false)
   **/
  constructor(images = [], allowRemote = false) {
    this.allowRemote = allowRemote
    this.hosturl = window.location.protocol + '//' + window.location.host
    let j = window.location.pathname.lastIndexOf('/')
    this.baseurl = this.hosturl + window.location.pathname.substring(0, j)

    this.images = []

    for (var i = 0; i < images.length; i++) {
      this.addImage(images[i])
    }
    this.size = this.images.length
  }

  /**
   * Add an image to the list
   **/
  addImage(url) {
    if (this.allowRemote) {
      if (
        url.startsWith('file://') ||
        url.startsWith('http://') ||
        url.startsWith('https://')
      ) {
        this.images.push(url)
      } else {
        alert(
          'This installation is configured to allow remote URLs. Please use absolute URLs for all image locations.'
        )
      }
    } else {
      if (url.startsWith('/')) {
        this.images.push(this.hosturl + url)
      } else if (url.startsWith(this.hosturl)) {
        this.images.push(url)
      } else if (url.includes(':')) {
        alert(
          'Can not load image: ' + url + 'images must be on the same vHost.'
        )
      } else {
        this.images.push(this.baseurl + '/' + url)
      }
    }
  }

  /**
   * Get an image by index from the list.
   **/
  getImage(index) {
    if (index < this.size && index >= 0) {
      return this.images[index]
    } else {
      return ''
    }
  }

  /**
   * Show a html list of the images at the specified location.
   **/
  displayImageList(svgSelector) {
    var g = d3.select(svgSelector)
    g.append('xhtml:p').text(
      'Note: if you want to restore the JSON configuration on an other installation, download the following images too:'
    )
    var o = g.append('xhtml:ol')
    for (var image of this.images) {
      o.append('xhtml:li')
        .append('xhtml:a')
        .attr('href', image)
        .text(image)
    }
  }
}

export default Gallery