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module Arel
module Visitors
class Dot
class Node # :nodoc:
attr_accessor :name, :id, :fields
def initialize name, id, fields = []
@name = name
@id = id
@fields = fields
end
end
class Edge < Struct.new :name, :from, :to # :nodoc:
end
def initialize
@nodes = []
@edges = []
@node_stack = []
@edge_stack = []
@seen = {}
end
def accept object
visit object
to_dot
end
private
def visit_Arel_Nodes_TableAlias o
visit_edge o, "name"
visit_edge o, "relation"
visit_edge o, "columns"
end
def visit_Arel_Nodes_Count o
visit_edge o, "expressions"
visit_edge o, "distinct"
end
def visit_Arel_Nodes_StringJoin o
visit_edge o, "left"
visit_edge o, "right"
end
alias :visit_Arel_Nodes_InnerJoin :visit_Arel_Nodes_StringJoin
def visit_Arel_Nodes_InsertStatement o
visit_edge o, "relation"
visit_edge o, "columns"
visit_edge o, "values"
end
def visit_Arel_Nodes_SelectCore o
visit_edge o, "froms"
visit_edge o, "projections"
visit_edge o, "wheres"
end
def visit_Arel_Nodes_SelectStatement o
visit_edge o, "cores"
visit_edge o, "limit"
end
def visit_Arel_Nodes_UpdateStatement o
visit_edge o, "relation"
visit_edge o, "wheres"
visit_edge o, "values"
end
def visit_Arel_Table o
visit_edge o, "name"
end
def visit_Arel_Attribute o
visit_edge o, "relation"
visit_edge o, "name"
end
alias :visit_Arel_Attributes_Integer :visit_Arel_Attribute
alias :visit_Arel_Attributes_String :visit_Arel_Attribute
alias :visit_Arel_Attributes_Time :visit_Arel_Attribute
alias :visit_Arel_Attributes_Boolean :visit_Arel_Attribute
def visit_Arel_Nodes_Equality o
visit_edge o, "left"
visit_edge o, "right"
end
def visit_String o
@node_stack.last.fields << o
end
alias :visit_Time :visit_String
alias :visit_NilClass :visit_String
alias :visit_TrueClass :visit_String
alias :visit_Arel_SqlLiteral :visit_String
alias :visit_Fixnum :visit_String
alias :visit_Symbol :visit_String
def visit_Hash o
o.each_with_index do |pair, i|
edge("pair_#{i}") { visit pair }
end
end
def visit_Array o
o.each_with_index do |x,i|
edge(i) { visit x }
end
end
def visit_edge o, method
edge(method) { visit o.send(method) }
end
def visit o
if node = @seen[o.object_id]
@edge_stack.last.to = node
return
end
node = Node.new(o.class.name, o.object_id)
@seen[node.id] = node
@nodes << node
with_node node do
send "visit_#{o.class.name.gsub('::', '_')}", o
end
end
def edge name
edge = Edge.new(name, @node_stack.last)
@edge_stack.push edge
@edges << edge
yield
@edge_stack.pop
end
def with_node node
if edge = @edge_stack.last
edge.to = node
end
@node_stack.push node
yield
@node_stack.pop
end
def quote string
string.to_s.gsub('"', '\"')
end
def to_dot
"digraph \"ARel\" {\nnode [width=0.375,height=0.25,shape=record];\n" +
@nodes.map { |node|
label = "<f0>#{node.name}"
node.fields.each_with_index do |field, i|
label << "|<f#{i + 1}>#{quote field}"
end
"#{node.id} [label=\"#{label}\"];"
}.join("\n") + "\n" + @edges.map { |edge|
"#{edge.from.id} -> #{edge.to.id} [label=\"#{edge.name}\"];"
}.join("\n") + "\n}"
end
end
end
end
|
