force :xhtml if template.mime_type == 'text/xml'

If the mime_type of the ActionView::Template template
being rendered is 'text/xml' then add the a :mime_type
key to the options hash so Haml::Engine will force a
format of xhtml.

Closes #427

Signed-off-by: Norman Clarke <norman@njclarke.com>

CHANGELOG.md

@@ -22,6 +22,10 @@
 * Fix parser to allow lines ending with `some_method?` to be a Ruby multinline
   (thanks to [Brad Ediger](https://github.com/bradediger))
 
+* Always use :xhtml format when the mime_type of the rendered template is 'text/xml'.
+  (thanks to [Stephen Bannasch](https://github.com/stepheneb)).
+
+
 ## 3.1.5 (Unreleased)
 
 * Respect Rails' `html_safe` flag when escaping attribute values

REFERENCE.md

@@ -133,6 +133,10 @@ Available options are:
   Other options are `:html4` and `:html5`, which are
   identical to `:xhtml` except there are no self-closing tags,
   the XML prolog is ignored and correct DOCTYPEs are generated.
+  <br/><br/> <!-- There's no better way to do a paragraph break in a dl in Maruku -->
+  If the mime_type of the template being rendered is `text/xml` then
+  a format of `:xhtml` will be used even if the global output format
+  is set to `:html4` or `:html5`.
 
 {#escape_html-option} `:escape_html`
 : Sets whether or not to escape HTML-sensitive characters in script.
@@ -839,6 +843,10 @@ is compiled to:
 
     <?xml version='1.0' encoding='iso-8859-1' ?>
 
+If the mime_type of the template being rendered is `text/xml` then
+a format of `:xhtml` will be used even if the global output format
+is set to `:html4` or `:html5`.
+
 ## Comments
 
 Haml supports two sorts of comments:

lib/haml/template/plugin.rb

@@ -21,6 +21,8 @@ module Haml
     def compile(template)
       options = Haml::Template.options.dup
 
+      options[:mime_type] = template.mime_type
+
       # template is a template object in Rails >=2.1.0,
       # a source string previously
       if template.respond_to? :source
@@ -99,7 +101,7 @@ if defined?(ActionView::TemplateError) &&
       begin
         render_source = create_template_source(handler, template, render_symbol, local_assigns.keys)
         line_offset = @@template_args[render_symbol].size + handler.line_offset
-      
+
         file_name = 'compiled-template' if file_name.blank?
         CompiledTemplates.module_eval(render_source, file_name, -line_offset)
       rescue Exception => e # errors from template code
@@ -112,10 +114,10 @@ if defined?(ActionView::TemplateError) &&
         # There's no way to tell Haml about the filename,
         # so we've got to insert it ourselves.
         e.backtrace[0].gsub!('(haml)', file_name) if e.is_a?(Haml::Error)
-        
+
         raise ActionView::TemplateError.new(extract_base_path_from(file_name) || view_paths.first, file_name || template, @assigns, template, e)
       end
-      
+
       @@compile_time[render_symbol] = Time.now
       # logger.debug "Compiled template #{file_name || template}\n ==> #{render_symbol}" if logger
     end