EWF/library/extras/visitor/json_pretty_string_visitor.e

note
	description: "JSON_PRETTY_STRING_VISITOR Generates the JSON-String for a JSON_VALUE"
	revision: "0.1"

class
	JSON_PRETTY_STRING_VISITOR

inherit
	JSON_VISITOR

create
	make,
	make_custom

feature -- Initialization

	make (a_output: like output)
			-- Create a new instance
		do
			make_custom (a_output, 1, 1)
		end

	make_custom (a_output: like output; a_object_count_inlining, a_array_count_inlining: INTEGER)
			-- Create a new instance
		do
			output := a_output
			create indentation.make_empty
			indentation_step := "%T"

			object_count_inlining := a_object_count_inlining
			array_count_inlining := a_array_count_inlining
		end

feature -- Access

	output: STRING_32
		-- JSON representation

	indentation: like output

	indentation_step: like indentation

	line_number: INTEGER

	indent
		do
			indentation.append (indentation_step)
		end

	exdent
		do
			indentation.remove_tail (indentation_step.count)
		end

	new_line
		do
			output.append ("%N")
			output.append (indentation)
			line_number := line_number + 1
		end

	object_count_inlining: INTEGER
	array_count_inlining: INTEGER

feature -- Visitor Pattern

	visit_json_array (a_json_array: JSON_ARRAY)
			-- Visit `a_json_array'.
		local
			value: JSON_VALUE
			l_json_array: ARRAYED_LIST [JSON_VALUE]
			l_line: like line_number
			l_multiple_lines: BOOLEAN
		do
			l_json_array := a_json_array.array_representation
			l_multiple_lines := l_json_array.count >= array_count_inlining or across l_json_array as p some attached {JSON_OBJECT} p.item or attached {JSON_ARRAY} p.item end
			output.append ("[")
			l_line := line_number
			indent
			from
				l_json_array.start
			until
				l_json_array.off
			loop
				if
					line_number > l_line or
					l_multiple_lines
				then
					new_line
				end
				value := l_json_array.item
				value.accept (Current)
				l_json_array.forth
				if not l_json_array.after then
					output.append (", ")
				end
			end
			exdent
			if 
				line_number > l_line or
				l_json_array.count >= array_count_inlining 
			then
				new_line
			end
			output.append ("]")
		end

	visit_json_boolean (a_json_boolean: JSON_BOOLEAN)
			-- Visit `a_json_boolean'.
		do
			output.append (a_json_boolean.item.out)
		end

	visit_json_null (a_json_null: JSON_NULL)
			-- Visit `a_json_null'.
		do
			output.append ("null")
		end

	visit_json_number (a_json_number: JSON_NUMBER)
			-- Visit `a_json_number'.
		do
			output.append (a_json_number.item)
		end

	visit_json_object (a_json_object: JSON_OBJECT)
			-- Visit `a_json_object'.
		local
			l_pairs: HASH_TABLE [JSON_VALUE, JSON_STRING]
			l_line: like line_number
			l_multiple_lines: BOOLEAN
		do
			l_pairs := a_json_object.map_representation
			l_multiple_lines := l_pairs.count >= object_count_inlining or across l_pairs as p some attached {JSON_OBJECT} p.item or attached {JSON_ARRAY} p.item end
			output.append ("{")
			l_line := line_number
			indent
			from
				l_pairs.start
			until
				l_pairs.off
			loop
				if 
					line_number > l_line or
					l_multiple_lines
				then
					new_line
				end
				l_pairs.key_for_iteration.accept (Current)
				output.append (": ")
				l_pairs.item_for_iteration.accept (Current)
				l_pairs.forth
				if not l_pairs.after then
					output.append (", ")
				end
			end
			exdent
			if 
				line_number > l_line or
				l_pairs.count >= object_count_inlining 
			then
				new_line
			end
			output.append ("}")
		end

    visit_json_string (a_json_string: JSON_STRING)
			-- Visit `a_json_string'.
		do
			output.append ("%"")
			output.append (a_json_string.item)
			output.append ("%"")
		end

end