Initial

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 84 insertions, 0 deletions

diff --git a/actionpack/lib/action_view/template_error.rb b/actionpack/lib/action_view/template_error.rb
new file mode 100644
index 0000000000..ab05b3303f
--- /dev/null
+++ b/actionpack/lib/action_view/template_error.rb
@@ -0,0 +1,84 @@
+module ActionView
+  # The TemplateError exception is raised when the compilation of the template fails. This exception then gathers a
+  # bunch of intimate details and uses it to report a very precise exception message.
+  class TemplateError < ActionViewError #:nodoc:
+    SOURCE_CODE_RADIUS = 3
+
+    attr_reader :original_exception
+
+    def initialize(base_path, file_name, assigns, source, original_exception)
+      @base_path, @file_name, @assigns, @source, @original_exception = 
+        base_path, file_name, assigns, source, original_exception
+    end
+  
+    def message
+      if original_exception.message.include?("(eval):")
+        original_exception.message.scan(/\(eval\):(?:[0-9]*):in `.*'(.*)/).first.first
+      else
+        original_exception.message
+      end
+    end
+  
+    def sub_template_message
+      if @sub_templates
+        "Trace of template inclusion: " +
+        @sub_templates.collect { |template| strip_base_path(template) }.join(", ")
+      else
+        ""
+      end
+    end
+  
+    def source_extract
+      source_code = IO.readlines(@file_name)
+      
+      start_on_line = [ line_number - SOURCE_CODE_RADIUS - 1, 0 ].max
+      end_on_line   = [ line_number + SOURCE_CODE_RADIUS - 1, source_code.length].min
+
+      line_counter = start_on_line
+      extract = source_code[start_on_line..end_on_line].collect do |line| 
+        line_counter += 1
+        "#{line_counter}: " + line
+      end
+    
+      extract.join
+    end
+  
+    def sub_template_of(file_name)
+      @sub_templates ||= []
+      @sub_templates << file_name
+    end
+  
+    def line_number
+      begin
+        @original_exception.backtrace.join.scan(/\((?:erb)\):([0-9]*)/).first.first.to_i
+      rescue
+        begin
+          original_exception.message.scan(/\((?:eval)\):([0-9]*)/).first.first.to_i
+        rescue
+          1
+        end
+      end
+    end
+  
+    def file_name
+      strip_base_path(@file_name)
+    end
+    
+    def to_s
+      "\n\n#{self.class} (#{message}) on line ##{line_number} of #{file_name}:\n" + 
+      source_extract + "\n    " +
+      clean_backtrace(original_exception).join("\n    ") +
+      "\n\n"
+    end
+
+    private
+      def strip_base_path(file_name)
+        file_name.gsub(@base_path, "")
+      end
+
+      def clean_backtrace(exception)
+        base_dir = File.expand_path(File.dirname(__FILE__) + "/../../../../")
+        exception.backtrace.collect { |line| line.gsub(base_dir, "").gsub("/public/../config/environments/../../", "").gsub("/public/../", "") }
+      end
+  end
+end
\ No newline at end of file