lib/publify_textfilter_lightbox.rb

Summary

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5 hrs
Test Coverage
# frozen_string_literal: true

class PublifyApp
  class Textfilter
    class Lightbox < TextFilterPlugin::MacroPost
      plugin_display_name "Lightbox"
      plugin_description "Automatically generate tags for images displayed in a lightbox"

      def self.help_text
        <<~TXT
          You can use `<publify:lightbox>` to display images from [Flickr](http://flickr.com)
          or a provided URL which, when clicked, will be shown in a lightbox using Lokesh Dhakar's
          [Lightbox](http://www.huddletogether.com/projects/lightbox/) Javascript

          Example:

              <publify:lightbox img="31367273" thumbsize="thumbnail" displaysize="original"/>
              <publify:lightbox src="/files/myimage.png" thumbsrc="/files/myimage-thumb.png"/>

          The first will produce an `<img>` tag showing image number 31367273
          from Flickr using the thumbnail image size.  The image will be linked
          to the original image file from Flickr.  When the link is clicked,
          the larger picture will be overlaid on top of the existing page
          instead of taking you over to the Flickr site.
          The second will do the same but use the `src` URL as the large
          picture and the `thumbsrc` URL as the thumbnail image. To understand
          what this looks like, have a peek at Lokesh Dhakar's
          [examples](http://www.huddletogether.com/projects/lightbox/).
          It will also have a comment block attached if a description has been
          attached to the picture in Flickr or the caption attribute is used.

          For theme writers, the link is enclosed in a div tag with a "lightboxplugin"
          class.  Because this filter requires javascript and css include files, it
          will only work with themes using the `<%= page_header %>` convenience function
          in their layouts. As of this writing only Azure does this.

          This macro takes a number of parameters:

          Flickr attributes:

          * **img** The Flickr image ID of the picture that you wish to use.
            This shows up in the URL whenever you're viewing a picture in Flickr;
            for example, the image ID for
            <http://flickr.com/photos/scottlaird/31367273> is 31367273.
          * **thumbsize** The image size that you'd like to display. Typically
            you would use square, thumbnail or small. Options are:
            * square (75x75)
            * thumbnail (maximum size 100 pixels)
            * small (maximum size 240 pixels)
            * medium (maximum size 500 pixels)
            * large (maximum size 1024 pixels)
            * original
          * **displaysize** The image size for the lightbox overlay shown when
            the user clicks the thumbnail.  Options are the same as for
            thumbsize, but typically you would use medium or large.  If your
            image files are quite large on Flickr you probably want to avoid
            using original.

          Direct URL attributes:

          * **src** The URL to the picture you wish to use.
          * **thumbsrc** The URL to the thumbnail you would like to use. If
            this is not provided, the original picture will be used with the
            width and height properties of the `<img>` tag set to 100x100.

          Common attributes:

          * **style** This is passed through to the enclosing `<div>` that this
            macro generates. To float the image on the right, use
            `style="float:right"`.
          * **caption** The caption displayed below the image. By default,
            this is Flickr's description of the image. to disable, use
            `caption=""`.
          * **title** The tooltip title associated with the image. Defaults to
            Flickr's image title.
          * **alt** The alt text associated with the image. By default, this is
            the same as the title.
          * **set** Add image to a set
          * **class** adds an existing CSS class
        TXT
      end

      def self.macrofilter(attrib, _text = "")
        # FIXME: style is not used
        # style = attrib['style']
        caption = attrib["caption"]
        title = attrib["title"]
        alt = attrib["alt"]
        theclass = attrib["class"]
        set = attrib["set"]
        thumburl = ""
        displayurl = ""

        img = attrib["img"]
        if img
          thumbsize = attrib["thumbsize"] || "square"
          displaysize = attrib["displaysize"] || "original"

          flickrimage = flickr.photos.getInfo(photo_id: img)
          sizes = flickr.photos.getSizes(photo_id: img)

          thumbdetails =
            sizes.find { |s| s["label"].casecmp(thumbsize.downcase).zero? } || sizes.first
          displaydetails =
            sizes.find { |s| s["label"].casecmp(displaysize.downcase).zero? } || sizes.first

          width = thumbdetails["width"]
          height = thumbdetails["height"]

          # use protocol-relative URL after getting the source address
          # so not to break HTTPS support
          thumburl = thumbdetails["source"].sub(/^https?:/, "")
          displayurl = displaydetails["source"].sub(/^https?:/, "")

          caption ||= flickrimage.description
          title ||= flickrimage.title
          alt ||= title
        else
          thumburl = attrib["thumbsrc"] unless attrib["thumbsrc"].nil?
          displayurl = attrib["src"] unless attrib["src"].nil?

          if thumburl.empty?
            thumburl = displayurl
            width = 100
            height = 100
          else
            width = height = nil
          end
        end

        rel = set.blank? ? "lightbox" : "lightbox[#{set}]"

        captioncode = if caption.blank?
                        ""
                      else
                        "<p class=\"caption\" style=\"width:#{width}px\">#{caption}</p>"
                      end

        img_attrs = +%(src="#{thumburl}")
        img_attrs << %( class="#{theclass}") if theclass
        img_attrs << %( width="#{width}") if width
        img_attrs << %( height="#{height}") if height
        img_attrs << %( alt="#{alt}" title="#{title}")
        "<a href=\"#{displayurl}\" data-toggle=\"#{rel}\" title=\"#{title}\">" \
          "<img #{img_attrs}/></a>#{captioncode}"
      end
    end
  end
end