/tutorial/xml/dom/example1.e

  1class EXAMPLE1
  2   --
  3   -- This simple example just uses XML_TREE.
  4   --
  5   -- See EXAMPLE2 on how to extend XML_TREE to add validation features.
  6   --
  7
  8inherit
  9   XML_NODE_VISITOR
 10
 11insert
 12   ARGUMENTS
 13
 14create {}
 15   make
 16
 17feature {}
 18   make
 19      local
 20         in: TEXT_FILE_READ; tree: XML_TREE; version: UNICODE_STRING
 21      do
 22         if argument_count = 0 then
 23            std_error.put_line(once "Usage: #(1) <file.xml>" # command_name)
 24            die_with_code(1)
 25         end
 26         -- first create the stream
 27         create in.connect_to(argument(1))
 28         if in.is_connected then
 29            -- then create the tree
 30            create tree.with_error_handler(in.url, agent error(?, ?))
 31            -- now display the results
 32            version := tree.attribute_at(once U"version")
 33            if version /= Void then
 34               io.put_string(once "XML version: ")
 35               io.put_string(version.as_utf8)
 36               io.put_new_line
 37            end
 38
 39            check
 40               indent = 0
 41            end
 42            tree.root.accept(Current)
 43         end
 44      end
 45
 46   indent: INTEGER
 47
 48feature {XML_DATA_NODE}
 49   visit_data_node (node: XML_DATA_NODE)
 50      do -- data not displayed in this example
 51      end
 52
 53feature {XML_COMPOSITE_NODE}
 54   visit_composite_node (node: XML_COMPOSITE_NODE)
 55      local
 56         i, start_indent: INTEGER
 57      do
 58         from
 59            i := 1
 60         until
 61            i > indent
 62         loop
 63            io.put_string(once "  ")
 64            i := i + 1
 65         end
 66         io.put_string(node.name.as_utf8)
 67         if node.attributes_count > 0 then
 68            io.put_character('(')
 69            from
 70               i := 1
 71            until
 72               i > node.attributes_count
 73            loop
 74               if i > 1 then
 75                  io.put_string(once ", ")
 76               end
 77               io.put_string(node.attribute_name(i).as_utf8)
 78               io.put_character('=')
 79               io.put_string(node.attribute_value(i).as_utf8)
 80               i := i + 1
 81            end
 82
 83            io.put_character(')')
 84         end
 85
 86         io.put_new_line
 87         from
 88            start_indent := indent
 89            indent := start_indent + 1
 90            i := 1
 91         invariant
 92            indent = start_indent + 1
 93         until
 94            i > node.children_count
 95         loop
 96            node.child(i).accept(Current)
 97            i := i + 1
 98         end
 99
100         indent := start_indent
101      end
102
103   error (line, column: INTEGER)
104      do
105         std_error.put_string(once "Error at ")
106         std_error.put_integer(line)
107         std_error.put_string(once ", ")
108         std_error.put_integer(column)
109         std_error.put_string(once "!%N")
110         die_with_code(1)
111      end
112
113end -- class EXAMPLE1