Class: Oinky::Model::Ruby

Inherits:
Object
  • Object
show all
Defined in:
lib/oinky/rb_emitter.rb

Instance Method Summary collapse

Constructor Details

#initialize(schema) ⇒ Ruby

Returns a new instance of Ruby.



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# File 'lib/oinky/rb_emitter.rb', line 11

def initialize(schema)
  @schema = Oinky::Model.normalize_schema(schema)
end

Instance Method Details

#default_value_expression(col) ⇒ Object

def handle_from_tablename(str) ; “#cppify(str)_handle” ; end def accessor_from_tablename(str) ; cppify(str) ; end



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# File 'lib/oinky/rb_emitter.rb', line 37

def default_value_expression(col)
  value = col
  value = col[:default] if col.is_a? Hash
  return "DateTime.parse(#{value.to_s.inspect})" if value.is_a? DateTime
  return value.inspect
end

#emit ⇒ Object

Generate a string, containing the Ruby code for the model classes. this can be eval’d directly in ruby, or saved and required more normally. Supporting both lends itself to static analysis and transformation moreso than if we solved this with ruby metaprogramming.



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# File 'lib/oinky/rb_emitter.rb', line 67

def emit
  p = Oinky::Detail::Builder.new
  schemacls = self.schema_classname
  p.next("class #{schemacls}", "end ##{schemacls}") {
    tables = @schema[:tables]
    p.next("def self.schema", "end") {
      p << to_ruby(@schema.merge(:classname=>schemacls))
    }
    p.next("def schema", "end") {
      p << 'self.class.schema'
    }
    p << ''
    p.next("def inspect", "end") {
      # Hide all the internal state, which gets really obnoxious
      p << '"#<#{self.class}:0x#{self.__id__.to_s(16)}>"'
      # This is just a bit long to include.
      #schema=#{self.schema.to_s}>"'
    }
    p << ''
    tables.each{|nm,t|
      clsname = tbl_classname(nm)
      p.next("class #{clsname}","end ##{clsname}") {
        p << "include Oinky::Model::Table"
        p << ''
        p.next("def initialize(tbl)","end") {
          p << "@tbl = tbl"
          p << "self.class.migrate(tbl)"
          p << ''
          t[:indices].each {|k,v|
            accessor = rbify_method(v[:accessor])
            p << "@#{accessor} = @tbl.indices[#{k.inspect}]"
          }
        }
        p << ''
        p.next("def self.migrate(tbl)","end") {
          p.next("tbl.db.atomic {", "}") {
            p << "cols = tbl.columns"
            t[:columns].each{|k,v|
              p.next("if c = cols[#{k.inspect}]","end") {
                p << "raise OinkyException.new('Mismatched column type for column [#{k.to_s}]') unless c[:type] == :#{v[:type]}"
                p.write("else",-1)
                p << "tbl.add_column(#{k.inspect},#{v[:type].inspect},#{default_value_expression(v)})"
              }                  
            }
            p << "ixs = tbl.indices"
            t[:indices].each{|k,v|
              p.next("unless ixs[#{k.inspect}]","end") {
                p << "tbl.add_index(:name=>#{k.inspect},:unique=>#{v[:unique]},:columns=>#{v[:columns]})"
              }                  
            }
          }
        }
        p << ''
        t[:indices].each {|k,v|
          accessor = rbify_method(v[:accessor])
          p << "attr_accessor :#{accessor}"
        }
        p << "def table ; @tbl ; end"
        p << "alias :t :table"
      } #tablecls
      p << ''
    } #tables.each

    p.next("def initialize(db, prefix = '')","end") {
      tables.each{|nm,t|
        accessor = rbify_method(t[:accessor])
        p << "tn = prefix + #{nm.inspect}"
        p << "db[tn] or db.create_table(tn)"
        p << "@#{accessor} = #{tbl_classname(nm)}.new(db[tn])"
      }
    }
    tables.each{|nm,t|
      accessor = rbify_method(t[:accessor])
      p << "attr_accessor :#{accessor}"
    }
  } #schemacls
  return p.format
end

#rbify_chars(str) ⇒ Object 



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# File 'lib/oinky/rb_emitter.rb', line 21

def rbify_chars(str)
  str = str.gsub(/[^a-z0-9A-Z_]/,'_')
end

#rbify_method(str) ⇒ Object 



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# File 'lib/oinky/rb_emitter.rb', line 15

def rbify_method(str)
  str = str.gsub(/[^a-z0-9A-Z_]/,'_')
  return str unless /$[^a-z]/ =~ str
  return "_" + str
end

#schema_classname ⇒ Object 



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# File 'lib/oinky/rb_emitter.rb', line 25

def schema_classname
  cn = @schema[:classname]
  return "S#{@schema[:name].to_s}Adapter" unless cn
  return cn[:ruby] if cn.is_a? Hash
  return cn.call(:ruby) if cn.is_a? Proc
  return cn.to_s
end

#tbl_classname(str) ⇒ Object 



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# File 'lib/oinky/rb_emitter.rb', line 33

def tbl_classname(str) ; "Table_#{rbify_chars(str)}" ; end

#to_ruby(h) ⇒ Object 



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# File 'lib/oinky/rb_emitter.rb', line 44

def to_ruby(h)
  str = ['{']
  h.each {|k,v|
    str << k.inspect + "=>"
    if v.is_a? Hash
      str << to_ruby(v)
    elsif v.is_a? DateTime
      str << default_value_expression(v)
    else
      str << v.inspect
    end
    str << ','
  }
  str << '}'
  return str * ''
end