Merge pull request #149 from grundprinzip/templating

Templating + Fixes for Static and PDF Generation

README.rdoc

@@ -84,7 +84,23 @@ the following contents:
 
 That represents two slides, the first contains just a large title, and the
 second is faded into view showing the title and three bullets that are then
-incrementally shown. In order for ShowOff to see those slides, your
+incrementally shown. In addition you can configure a certain template for 
+this slide overriding the default one:
+
+     !SLIDE[tpl=title]
+
+     # My Presentation #
+
+     !SLIDE bullets incremental
+
+     # Bullet Points #
+
+     * first point
+     * second point
+     * third point
+
+
+In order for ShowOff to see those slides, your
 <tt>showoff.json</tt> file needs to look something like this:
 
     {
@@ -95,19 +111,20 @@ incrementally shown. In order for ShowOff to see those slides, your
       ]
     }
 
-If you have multiple sections in your talk, you can make this json array
-include all the sections you want to show in which order you want to show
-them.
+If you have multiple sections in your talk, you can make this json
+array include all the sections you want to show in which order you
+want to show them. Template configuration is done in
+<tt>showoff.json</tt> as well. 
 
-Instead of a hash, you can use a plain string as an entry in the `sections`
-section of `showoff.json`.
 
-And if that plain string starts with '#' then it is interpreted not as a
-filename, but as markdown. This is used for inserting interstitial slides
-or notes -- for instance, Alex Chaffee's
-[Ruby Notes](http://github.com/alexch/ruby_notes)
-uses it to insert lab instructions between lecture slide sections, which may
-vary from venue to venue.
+Instead of a hash, you can use a plain string as an entry in the
+`sections` section of `showoff.json`. And if that plain string starts
+with '#' then it is interpreted not as a filename, but as
+markdown. This is used for inserting interstitial slides or notes --
+for instance, Alex Chaffee's [Ruby
+Notes](http://github.com/alexch/ruby_notes) uses it to insert lab
+instructions between lecture slide sections, which may vary from venue
+to venue.
 
 If you want to keep the ability to emit an HTML document from your
 Markdown source file -- say, for a TextMate preview or a GitHub rendering
@@ -447,6 +464,62 @@ You'll then need to install a version of wkhtmltopdf available at the {wkhtmltop
 
 Then restart showoff, and navigate to <tt>/pdf</tt> (e.g. http://localhost/pdf) of your presentation and a PDF will be generated with the browser.
 
+= ShowOff Templates
+
+Templates can come handy if you need more than what you can achieve
+via CSS. To configure templates you'll have to specify them in the
+<tt>showoff.json</tt> by adding an entry called "templates". This
+entry is an object where you can specify as many templates as you
+want. The default template is marked with the "default" key.
+
+     {
+      "name": "Something",
+      "description": "Example Presentation",
+      "templates" : {
+          "default" : "tpl1.tpl",
+	  "special" : "tpl2.tpl"
+      },    
+      "sections": [
+        {"section":"one"}
+      ]
+    }
+
+If the "default" key is not given, no template will be used for the
+default slide. If you want to apply a certain layout to a slide you
+have to specify it in the slide header:
+
+     !SLIDE[tpl=special]
+     # Header
+
+== Template Commands
+
+You can place content anywhere in your template, but you have to
+explicitly mark the location using a special command:
+
+[~~~CONTENT~~~] is replaced by the slide content
+
+[~~~CURRENT_SLIDE~~~] is replaced by the current slide number
+
+[~~~NUM_SLIDES~~~] is replaced by the total number of slides
+
+[~~~CONFIG:*~~~] is replaced by any value (*) from the
+                 <tt>showoff.json</tt> configuration. This can be used to 
+		 specify an author, venue etc. A simple example would be
+		 <tt>~~~CONFIG:author~~~</tt>
+
+
+The usage of these replacements is not limited to templates, but
+anywhere in your slides. 
+
+== Template Hints
+
+You can basically put everything you want into templates, but you
+should make sure that the CSS is applied fine. The best way to apply a
+custom layout is to create a container that uses absolute positioning
+and has width and height set to 100% which are then derived from the
+parent slide element.
+
+
 = Completion
 
 == ZSH completion

example/four/01slide.md

@@ -0,0 +1,5 @@
+!SLIDE[tpl=special]
+
+# A Template #
+
+Really? How many slides? -- ~~~NUM_SLIDES~~~

example/showoff.json

@@ -1,9 +1,14 @@
 {
   "name": "Something",
   "description": "Example Presentation",
+  "author": "Foo Bar John",
+  "templates" : {
+      "special" : "simple.tpl"
+  },
   "sections": [
     {"section":"one"},
     {"section":"two"},
-    {"section":"three"}
+    {"section":"three"},
+    {"section":"four"}
   ]
 }

example/simple.tpl

@@ -0,0 +1,2 @@
+<div class="border">~~~CONFIG:author~~~@~~~CURRENT_SLIDE~~~</div>
+<div class="main">~~~CONTENT~~~<div>

lib/showoff.rb

@@ -33,6 +33,9 @@ class ShowOff < Sinatra::Application
   set :verbose, false
   set :pres_dir, '.'
   set :pres_file, 'showoff.json'
+  set :page_size, "Letter"
+  set :pres_template, nil
+  set :showoff_config, nil
 
   def initialize(app=nil)
     super(app)
@@ -51,6 +54,21 @@ def initialize(app=nil)
     if (settings.pres_file)
       ShowOffUtils.presentation_config_file = settings.pres_file
     end
+
+    # Load configuration for page size and template from the
+    # configuration JSON file
+    if File.exists?(ShowOffUtils.presentation_config_file)
+      showoff_json = JSON.parse(File.read(ShowOffUtils.presentation_config_file))
+      settings.showoff_config = showoff_json
+
+      # Set options for template and page size
+      settings.page_size = showoff_json["page-size"] || "Letter"
+      settings.pres_template = showoff_json["templates"] 
+    end
+
+
+    @logger.debug settings.pres_template
+
     @cached_image_size = {}
     @logger.debug settings.pres_dir
     @pres_name = settings.pres_dir.split('/').pop
@@ -96,9 +114,21 @@ def preshow_files
 
     # todo: move more behavior into this class
     class Slide
-      attr_reader :classes, :text
-      def initialize classes = ""
-        @classes = ["content"] + classes.strip.chomp('>').split
+      attr_reader :classes, :text, :tpl
+      def initialize( context = "")
+
+        @tpl = "default"
+        @classes = ["content"]
+
+        # Parse the context string for options and content classes
+        if context and context.match(/(\[(.*?)\])?(.*)/)
+
+          options = ShowOffUtils.parse_options($2)
+          @tpl = options["tpl"] if options["tpl"]
+          @classes += $3.strip.chomp('>').split if $3
+
+        end
+
         @text = ""
       end
       def <<(s)
@@ -126,7 +156,8 @@ def process_markdown(name, content, static=false, pdf=false)
       until lines.empty?
         line = lines.shift
         if line =~ /^<?!SLIDE(.*)>?/
-          slides << (slide = Slide.new($1))
+          ctx = $1 ? $1.strip : $1
+          slides << (slide = Slide.new(ctx))
         else
           slide << line
         end
@@ -139,6 +170,7 @@ def process_markdown(name, content, static=false, pdf=false)
         seq = 1
       end
       slides.each do |slide|
+        @slide_count += 1
         md = ''
         content_classes = slide.classes
 
@@ -151,27 +183,70 @@ def process_markdown(name, content, static=false, pdf=false)
         @logger.debug "id: #{id}" if id
         @logger.debug "classes: #{content_classes.inspect}"
         @logger.debug "transition: #{transition}"
+        @logger.debug "tpl: #{slide.tpl} " if slide.tpl
         # create html
         md += "<div"
         md += " id=\"#{id}\"" if id
         md += " class=\"slide\" data-transition=\"#{transition}\">"
+
+
+        template = "~~~CONTENT~~~"
+        # Template handling
+        if settings.pres_template
+          # We allow specifying a new template even when default is
+          # not given.
+          if settings.pres_template.include?(slide.tpl) and
+              File.exists?(settings.pres_template[slide.tpl])
+            template = File.open(settings.pres_template[slide.tpl], "r").read()
+          end
+        end
+
+        # Extract the content of the slide
+        content = ""
         if seq
-          md += "<div class=\"#{content_classes.join(' ')}\" ref=\"#{name}/#{seq.to_s}\">\n"
-          seq += 1
+          content += "<div class=\"#{content_classes.join(' ')}\" ref=\"#{name}/#{seq.to_s}\">\n"
         else
-          md += "<div class=\"#{content_classes.join(' ')}\" ref=\"#{name}\">\n"
+          content += "<div class=\"#{content_classes.join(' ')}\" ref=\"#{name}\">\n"
         end
         sl = Tilt[:markdown].new { slide.text }.render
         sl = update_image_paths(name, sl, static, pdf)
-        md += sl
-        md += "</div>\n"
+        content += sl
+        content += "</div>\n"
+
+        # Apply the template to the slide and replace the key with
+        # content of the slide
+        md += process_content_for_replacements(template.gsub(/~~~CONTENT~~~/, content), @slide_count)
+
+        # Apply other configuration
+
         md += "</div>\n"
         final += update_commandline_code(md)
         final = update_p_classes(final)
+
+        if seq
+          seq += 1
+        end
       end
       final
     end
 
+    # This method processes the content of the slide and replaces
+    # content markers with their actual value information
+    def process_content_for_replacements(content, seq)
+      result = content.gsub("~~~CURRENT_SLIDE~~~", seq.to_s)
+      # Now check for any kind of options
+      content.scan(/(~~~CONFIG:(.*?)~~~)/).each do |match|
+        result.gsub!(match[0], settings.showoff_config[match[1]]) if settings.showoff_config.key?(match[1])
+      end
+
+      result
+    end
+
+    def process_content_for_all_slides(content, num_slides)
+      content.gsub("~~~NUM_SLIDES~~~", num_slides.to_s)
+    end
+
+
     # find any lines that start with a <p>.(something) and turn them into <p class="something">
     def update_p_classes(markdown)
       markdown.gsub(/<p>\.(.*?) /, '<p class="\1">')
@@ -260,6 +335,7 @@ def update_commandline_code(slide)
     end
 
     def get_slides_html(static=false, pdf=false)
+      @slide_count = 0
       sections = ShowOffUtils.showoff_sections(settings.pres_dir, @logger)
       files = []
       if sections
@@ -280,7 +356,7 @@ def get_slides_html(static=false, pdf=false)
           end
         end
       end
-      data
+      process_content_for_all_slides(data, @slide_count)
     end
 
     def inline_css(csses, pre = nil)
@@ -319,6 +395,11 @@ def index(static=false)
       if static
         @title = ShowOffUtils.showoff_title
         @slides = get_slides_html(static)
+
+        # Identify which languages to bundle for highlighting
+        @languages = []
+        @languages += @slides.scan(/<pre class="(sh_.*?\w)"/).uniq.map{ |w| "sh_lang/#{w[0]}.min.js"}
+
         @asset_path = "./"
       end
       erb :index
@@ -377,9 +458,22 @@ def onepage(static=false)
     def pdf(static=true)
       @slides = get_slides_html(static, true)
       @no_js = false
+
+      # Identify which languages to bundle for highlighting
+      @languages = []
+      @languages += @slides.scan(/<pre class="(sh_.*?\w)"/).uniq.map{ |w| "/sh_lang/#{w[0]}.min.js"}
+
       html = erb :onepage
       # TODO make a random filename
 
+      # Process inline css and js for included images 
+      # The css uses relative paths for images and we prepend the file url
+      html.gsub!(/url\(([^\/].*?)\)/) do |s|
+        "url(file://#{settings.pres_dir}/#{$1})"
+      end
+
+      # Todo fix javascript path
+
       # PDFKit.new takes the HTML and any options for wkhtmltopdf
       # run `wkhtmltopdf --extended-help` for a full list of options
       kit = PDFKit.new(html, ShowOffUtils.showoff_pdf_options(settings.pres_dir))
@@ -403,6 +497,7 @@ def self.do_static(what)
       path = showoff.instance_variable_get(:@root_path)
       logger = showoff.instance_variable_get(:@logger)
       data = showoff.send(what, true)
+
       if data.is_a?(File)
         FileUtils.cp(data.path, "#{name}.pdf")
       else
@@ -479,7 +574,9 @@ def eval_ruby code
     @title = ShowOffUtils.showoff_title
     what = params[:captures].first
     what = 'index' if "" == what
+
     @asset_path = (env['SCRIPT_NAME'] || '').gsub(/\/?$/, '/').gsub(/^\//, '')
+
     if (what != "favicon.ico")
       data = send(what)
       if data.is_a?(File)

lib/showoff_utils.rb

@@ -1,4 +1,28 @@
 class ShowOffUtils
+
+  # Helper method to parse a comma separated options string and stores
+  # the result in a dictionrary
+  #
+  # Example:
+  # 
+  #    "tpl=hpi,title=Over the rainbow"
+  #
+  #    will be stored as
+  #
+  #      { "tpl" => "hpi", "title" => "Over the rainbow" }
+  def self.parse_options(option_string="")
+    result = {}
+
+    if option_string 
+      option_string.split(",").each do |element|
+        pair = element.split("=")
+        result[pair[0]] = pair.size > 1 ? pair[1] : nil
+      end
+    end
+
+    result
+  end
+
   def self.presentation_config_file
     @presentation_config_file ||= 'showoff.json'
   end