Do not raise when encountering an unsupported block

Output a warning, and simply ignore the block.

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## master
 
+- Don't raise an exception on missing blocks, merely log a warning
 - Implement `{TagsAsClasses}` tag
 
 ## 0.2.1

lib/tumblargh/renderer.rb

@@ -29,13 +29,16 @@ def self.factory(node, context, options = {})
           args << n_post[1].to_i
         end
 
-        base = "Blocks::#{block_name}"
+        base = "Blocks::#{ block_name }"
       end
 
-      klass_name = "Tumblargh::Renderer::#{base}"
-      klass = klass_name.constantize
-
-      klass.new(node, context, options, *args)
+      klass_name = "Tumblargh::Renderer::#{ base }"
+      begin
+        klass = klass_name.constantize
+        klass.new(node, context, options, *args)
+      rescue NameError => e
+        puts "WARNING: Unsupported block `#{ klass_name }`"
+      end
     end
 
   end

lib/tumblargh/renderer/base.rb

@@ -55,7 +55,6 @@ def render
       alias_method :to_s, :render
 
       def method_missing(method, *arguments)
-        # puts "mm #{method} - #{self.class.name} -- context is: #{context.class.name}"
         raise "Can't find anything to do with '#{method}'" if context.nil?
         context.send(method, *arguments)
       end

lib/tumblargh/renderer/blocks/base.rb

@@ -24,10 +24,11 @@ def render
           _, type, options, *nodes = node
 
           res = nodes.map do |n|
-            Renderer.factory(n, self, options).render
+            renderer = Renderer.factory(n, self, options)
+            renderer.render unless renderer.nil?
           end
 
-          " #{res.join('')} "
+          " #{ res.join('') } "
         end
       end
     end

lib/tumblargh/renderer/document.rb

@@ -55,7 +55,8 @@ def custom_value_for_type(type, key)
 
       def render
         node.map do |n|
-          Renderer.factory(n, self).render
+          renderer = Renderer.factory(n, self)
+          renderer.render unless renderer.nil?
         end.flatten.join('')
       end
     end

spec/renderer/blocks_spec.rb

@@ -3,37 +3,44 @@
 
 describe Tumblargh::Renderer::Blocks do
 
-  before do
-    @parser = Tumblargh::Parser.new
+  def capture_stdout(&block)
+    original_stdout = $stdout
+    $stdout = fake = StringIO.new
+    begin
+      yield
+    ensure
+      $stdout = original_stdout
+    end
+    fake.string
   end
 
+  let(:parser) { Tumblargh::Parser.new }
+
   describe "{block:PermalinkPage}" do
     before do
-      @parser.html = <<-eos
+      parser.html = <<-eos
         {block:PermalinkPage}
         ERMAGERD PERMERLINK
         {/block:PermalinkPage}
         eos
     end
 
     it "should render its content when it is a permalink page" do
-      @document = Tumblargh::Renderer::Document.new(@parser.tree, nil, :permalink => true)
-      @output = @document.render
-      @output.should match(/ERMAGERD PERMERLINK/)
+      document = Tumblargh::Renderer::Document.new(parser.tree, nil, :permalink => true)
+      output = document.render
+      output.should match(/ERMAGERD PERMERLINK/)
     end
 
     it "should NOT render its content when it is a permalink page" do
-      @document = Tumblargh::Renderer::Document.new(@parser.tree, nil, :permalink => false)
-      @output = @document.render
-      @output.should_not match(/ERMAGERD PERMERLINK/)
+      document = Tumblargh::Renderer::Document.new(parser.tree, nil, :permalink => false)
+      output = document.render
+      output.should_not match(/ERMAGERD PERMERLINK/)
     end
-
   end
 
   describe "boolean blocks" do
-
     before do
-      @parser.html = <<-eos
+      parser.html = <<-eos
       {block:IfSomethingOnByDefault}
       PASS_ON
       {/block:IfSomethingOnByDefault}
@@ -50,29 +57,51 @@
       PASS_INVERSE_OFF
       {/block:IfNotSomethingOffByDefault}
       eos
+    end
 
-      options = {
+    let(:options) do
+      {
         "if" => {
           "somethingonbydefault" => true,
           "somethingoffbydefault" => false
         }
       }
-
-      @document = Tumblargh::Renderer::Document.new(@parser.tree, nil, options)
-      @output = @document.render
     end
 
+    let(:output) { Tumblargh::Renderer::Document.new(parser.tree, nil, options).render }
+
     it "should respect the default settings" do
-      @output.should match(/PASS_ON/)
-      @output.should_not match(/FAIL_OFF/)
+      output.should match(/PASS_ON/)
+      output.should_not match(/FAIL_OFF/)
     end
 
 
     it "inverse (IfNot) blocks should work" do
-      @output.should_not match(/FAIL_INVERSE_ON/)
-      @output.should match(/PASS_INVERSE_OFF/)
+      output.should_not match(/FAIL_INVERSE_ON/)
+      output.should match(/PASS_INVERSE_OFF/)
     end
-
   end
 
+  describe "using unsupported blocks" do
+    before do
+      parser.html = <<-eos
+      {block:ThisIsDefinitelyNotABlock}{/block:ThisIsDefinitelyNotABlock}
+      eos
+    end
+
+    it "should not raise an error" do
+      expect {
+        Tumblargh::Renderer::Document.new(parser.tree, nil, {}).render
+      }.not_to raise_error
+    end
+
+    it "should output a warning" do
+      out = capture_stdout {
+        Tumblargh::Renderer::Document.new(parser.tree, nil, {}).render
+      }
+
+      out.should =~ /WARNING: Unsupported block `Tumblargh::Renderer::Blocks::ThisIsDefinitelyNotABlock`/
+    end
+
+  end
 end