Hrb: not as good as I thought

2019-06-18 20:17:37 -04:00
commit 517b911eea
26 changed files with 1152 additions and 0 deletions
--- a/lib/hrb.rb
+++ b/lib/hrb.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+require "hrb/version"
+require "hrb/template"
+require "hrb/tilt" if defined?(Tilt)
+require "hrb/action_view" if defined?(ActionView::Template)
+
+module Hrb
+  module_function
+
+  def render(locals: {}, scope: nil, &block)
+    Hrb::Template.render(locals: locals, scope: scope, &block)
+  end
+
+  def render_file(path, locals: {}, scope: nil)
+    Hrb::Template.render_file(path, locals: locals, scope: scope)
+  end
+end
--- a/lib/hrb/action_view.rb
+++ b/lib/hrb/action_view.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module Hrb
+  module Rails
+    class TemplateHandler
+      def call(template)
+        <<-CODE
+          Hrb::Template.build do
+            #{template.source}
+          end.to_s
+        CODE
+      end
+    end
+  end
+end
+
+ActionView::Template.register_template_handler :hrb, Hrb::Rails::TemplateHandler
--- a/lib/hrb/template.rb
+++ b/lib/hrb/template.rb
@@ -0,0 +1,131 @@
+# frozen_string_literal: true
+
+require "erb"
+
+module Hrb
+  class Template
+    TAGS = %i[a address article aside b bdi body button code details dialog div dd dl dt em fieldset figcaption figure
+              footer form h1 h2 h3 h4 h5 h6 head header html i iframe label li main mark menuitem meter nav ol option
+              option p pre progress rp rt ruby s script section select small span strong summary table tbody td textarea
+              th thead time title tr u ul video wbr].freeze
+    EMPTY_TAGS = %i[img br hr input link meta source].freeze
+
+    ENDINGS = Hash[TAGS.map do |tag|
+      [tag, "</#{tag}>"]
+    end].freeze
+
+    def self.render(locals: {}, scope: nil, &block)
+      template = Template.new(locals: locals, scope: scope)
+      template.instance_eval(&block)
+      template.to_s
+    end
+
+    def self.render_file(path, locals: {}, scope: nil)
+      template = Template.new(locals: locals, scope: scope)
+      template.instance_eval(File.read(path))
+      template.to_s
+    end
+
+    def initialize(locals: {}, scope: nil)
+      @fragments = [[]]
+      self.locals = locals
+      @scope = scope
+      @view = @fragments.last
+    end
+
+    TAGS.each do |name|
+      define_method(name) do |content = nil, options = {}, &block|
+        tag(name, content, options, &block)
+      end
+    end
+
+    EMPTY_TAGS.each do |name|
+      define_method(name) do |options = {}|
+        tag(name, nil, options, end_tag: false)
+      end
+    end
+
+    def tag(name, content = nil, options = {}, end_tag: true, &block)
+      output = "<#{name}#{tag_attributes(content&.is_a?(Hash) ? content : options)}>"
+      output += content if content&.is_a?(String)
+      output += capture(&block) if block
+      output += ENDINGS[name] if end_tag
+
+      raw output
+    end
+
+    def method_missing(name, *args, &block)
+      if @scope.respond_to?(name)
+        @scope.send(name, *args, &block)
+      elsif @locals&.key?(name) || @locals&.key?(name.to_s)
+        @locals.fetch(name) { @locals[name.to_s] }
+      else
+        super
+      end
+    end
+
+    def respond_to_missing?(name, include_all = false)
+      @scope.respond_to?(name) || @locals&.key?(name) || @locals&.key?(name.to_s) || super
+    end
+
+    def view
+      @fragments.last
+    end
+
+    def doctype
+      raw "<!DOCTYPE html>"
+    end
+
+    def text(output)
+      raw escape(output)
+    end
+
+    def raw(output)
+      view.push output.to_s
+    end
+
+    def capture(&block)
+      @fragments.push []
+      instance_eval(&block)
+
+      view.join.tap do
+        @fragments.pop
+      end
+    end
+
+    def locals=(locals)
+      locals.each do |key, value|
+        metaclass do
+          define_method key do
+            value
+          end
+        end
+      end
+    end
+
+    def to_s
+      @fragments.join
+    end
+
+    private
+
+    def metaclass(&block)
+      metaclass = class << self; self; end
+      metaclass.class_eval(&block)
+    end
+
+    def tag_attributes(options)
+      attrs = ""
+
+      options.each do |key, value|
+        attrs += %( #{key.to_s.tr("_", "-")}="#{escape(value)}")
+      end
+
+      attrs
+    end
+
+    def escape(value)
+      ERB::Util.html_escape(value.respond_to?(:join) ? value.join(" ") : value.to_s)
+    end
+  end
+end
--- a/lib/hrb/tilt.rb
+++ b/lib/hrb/tilt.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module Tilt
+  class HrbTemplate < Tilt::Template
+    def prepare; end
+
+    def evaluate(scope, locals, &block)
+      builder = Hrb::Template.new(locals: locals, scope: scope)
+
+      if block
+        builder.capture(&block)
+      else
+        builder.instance_eval(data)
+      end
+
+      builder.to_s
+    end
+  end
+
+  register Tilt::HrbTemplate, "rb"
+end
--- a/lib/hrb/version.rb
+++ b/lib/hrb/version.rb
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+module Hrb
+  VERSION = "1.0.0-alpha.1"
+end