1 files changed, 166 insertions, 0 deletions
diff --git a/lib/rexml/entity.rb b/lib/rexml/entity.rb
new file mode 100644
index 0000000..3d81fbc
--- /dev/null
+++ b/lib/rexml/entity.rb
@@ -0,0 +1,166 @@
+require 'rexml/child'
+require 'rexml/source'
+require 'rexml/xmltokens'
+
+module REXML
+  # God, I hate DTDs.  I really do.  Why this idiot standard still
+  # plagues us is beyond me.
+  class Entity < Child
+    include XMLTokens
+    PUBIDCHAR = "\x20\x0D\x0Aa-zA-Z0-9\\-()+,./:=?;!*@$_%#"
+    SYSTEMLITERAL = %Q{((?:"[^"]*")|(?:'[^']*'))}
+    PUBIDLITERAL = %Q{("[#{PUBIDCHAR}']*"|'[#{PUBIDCHAR}]*')}
+    EXTERNALID = "(?:(?:(SYSTEM)\\s+#{SYSTEMLITERAL})|(?:(PUBLIC)\\s+#{PUBIDLITERAL}\\s+#{SYSTEMLITERAL}))"
+    NDATADECL = "\\s+NDATA\\s+#{NAME}"
+    PEREFERENCE = "%#{NAME};"
+    ENTITYVALUE = %Q{((?:"(?:[^%&"]|#{PEREFERENCE}|#{REFERENCE})*")|(?:'([^%&']|#{PEREFERENCE}|#{REFERENCE})*'))}
+    PEDEF = "(?:#{ENTITYVALUE}|#{EXTERNALID})"
+    ENTITYDEF = "(?:#{ENTITYVALUE}|(?:#{EXTERNALID}(#{NDATADECL})?))"
+    PEDECL = "<!ENTITY\\s+(%)\\s+#{NAME}\\s+#{PEDEF}\\s*>"
+    GEDECL = "<!ENTITY\\s+#{NAME}\\s+#{ENTITYDEF}\\s*>"
+    ENTITYDECL = /\s*(?:#{GEDECL})|(?:#{PEDECL})/um
+
+    attr_reader :name, :external, :ref, :ndata, :pubid
+
+    # Create a new entity.  Simple entities can be constructed by passing a
+    # name, value to the constructor; this creates a generic, plain entity
+    # reference. For anything more complicated, you have to pass a Source to
+    # the constructor with the entity definition, or use the accessor methods.
+    # +WARNING+: There is no validation of entity state except when the entity
+    # is read from a stream.  If you start poking around with the accessors,
+    # you can easily create a non-conformant Entity.  The best thing to do is
+    # dump the stupid DTDs and use XMLSchema instead.
+    #
+    #  e = Entity.new( 'amp', '&' )
+    def initialize stream, value=nil, parent=nil, reference=false
+      super(parent)
+      @ndata = @pubid = @value = @external = nil
+      if stream.kind_of? Array
+        @name = stream[1]
+        if stream[-1] == '%'
+          @reference = true
+          stream.pop
+        else
+          @reference = false
+        end
+        if stream[2] =~ /SYSTEM|PUBLIC/
+          @external = stream[2]
+          if @external == 'SYSTEM'
+            @ref = stream[3]
+            @ndata = stream[4] if stream.size == 5
+          else
+            @pubid = stream[3]
+            @ref = stream[4]
+          end
+        else
+          @value = stream[2]
+        end
+      else
+        @reference = reference
+        @external = nil
+        @name = stream
+        @value = value
+      end
+    end
+
+    # Evaluates whether the given string matchs an entity definition,
+    # returning true if so, and false otherwise.
+    def Entity::matches? string
+      (ENTITYDECL =~ string) == 0
+    end
+
+    # Evaluates to the unnormalized value of this entity; that is, replacing
+    # all entities -- both %ent; and &ent; entities.  This differs from
+    # +value()+ in that +value+ only replaces %ent; entities.
+    def unnormalized
+      document.record_entity_expansion unless document.nil?
+      v = value()
+      return nil if v.nil?
+      @unnormalized = Text::unnormalize(v, parent)
+      @unnormalized
+    end
+
+    #once :unnormalized
+
+    # Returns the value of this entity unprocessed -- raw.  This is the
+    # normalized value; that is, with all %ent; and &ent; entities intact
+    def normalized
+      @value
+    end
+
+    # Write out a fully formed, correct entity definition (assuming the Entity
+    # object itself is valid.)
+    #
+    # out::
+    #   An object implementing <TT>&lt;&lt;<TT> to which the entity will be
+    #   output
+    # indent::
+    #   *DEPRECATED* and ignored
+    def write out, indent=-1
+      out << '<!ENTITY '
+      out << '% ' if @reference
+      out << @name
+      out << ' '
+      if @external
+        out << @external << ' '
+        if @pubid
+          q = @pubid.include?('"')?"'":'"'
+          out << q << @pubid << q << ' '
+        end
+        q = @ref.include?('"')?"'":'"'
+        out << q << @ref << q
+        out << ' NDATA ' << @ndata if @ndata
+      else
+        q = @value.include?('"')?"'":'"'
+        out << q << @value << q
+      end
+      out << '>'
+    end
+
+    # Returns this entity as a string.  See write().
+    def to_s
+      rv = ''
+      write rv
+      rv
+    end
+
+    PEREFERENCE_RE = /#{PEREFERENCE}/um
+    # Returns the value of this entity.  At the moment, only internal entities
+    # are processed.  If the value contains internal references (IE,
+    # %blah;), those are replaced with their values.  IE, if the doctype
+    # contains:
+    #  <!ENTITY % foo "bar">
+    #  <!ENTITY yada "nanoo %foo; nanoo>
+    # then:
+    #  doctype.entity('yada').value   #-> "nanoo bar nanoo"
+    def value
+      if @value
+        matches = @value.scan(PEREFERENCE_RE)
+        rv = @value.clone
+        if @parent
+          matches.each do |entity_reference|
+            entity_value = @parent.entity( entity_reference[0] )
+            rv.gsub!( /%#{entity_reference.join};/um, entity_value )
+          end
+        end
+        return rv
+      end
+      nil
+    end
+  end
+
+  # This is a set of entity constants -- the ones defined in the XML
+  # specification.  These are +gt+, +lt+, +amp+, +quot+ and +apos+.
+  module EntityConst
+    # +>+
+    GT = Entity.new( 'gt', '>' )
+    # +<+
+    LT = Entity.new( 'lt', '<' )
+    # +&+
+    AMP = Entity.new( 'amp', '&' )
+    # +"+
+    QUOT = Entity.new( 'quot', '"' )
+    # +'+
+    APOS = Entity.new( 'apos', "'" )
+  end
+end