Class: Fabulator::Expr::Context

Inherits:
Object
  • Object
show all
Defined in:
lib/fabulator/expr/context.rb

Instance Method Summary collapse

Constructor Details

#initialize(parent_c = nil, xml = nil) ⇒ Context

Returns a new instance of Context.



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# File 'lib/fabulator/expr/context.rb', line 5

def initialize(parent_c = nil, xml = nil)
  @parent = parent_c
  @run_time_parent = nil
  @ns = { }
  @attributes = { }
  @variables = { }
  @position = nil
  @last = nil
  @line_num = nil

  if parent_c.nil?
     if xml.nil? || (xml.root rescue nil).nil?
       roots = { }
       roots['data'] = Fabulator::Expr::Node.new('data', roots, nil, [])
       @root = roots['data']
     end
  end

  if !xml.nil?
    if xml.is_a?(self.class)
      @run_time_parent = xml
    else
      @line_num = xml.line_num

      parser = Fabulator::Expr::Parser.new

      xml.namespaces.each do |ns|
        @ns[ns.prefix] = ns.href
      end
      begin
        @ns[''] = xml.namespaces.default.href
      rescue
      end

      xml.each_attr do |attr|
        v = attr.value
        if !v.nil?
          @attributes[attr.ns.href.to_s] ||= {}
          @attributes[attr.ns.href.to_s][attr.name.to_s] = v
        end
      end
    end
  end
end

Instance Method Details

#attribute(ns, attr, popts = { }) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 80

def attribute(ns, attr, popts = { })
  opts = { :static => !@run_time_parent.nil? && !self.root.nil? }.update(popts)
  value = nil
  if @attributes.nil? || @attributes[ns].nil? || @attributes[ns].empty? || @attributes[ns][attr].nil?
    if opts[:inherited]
      value = @parent.nil? ? nil : @parent.attribute(ns, attr, opts)
    end
  else
    value = @attributes[ns][attr]
  end
  if value.nil? && !opts[:default].nil?
    value = opts[:default]
  end

  if !value.nil? && value.is_a?(String)
    e = nil
    if !opts[:eval]
      if value =~ /^\{(.*)\}$/
        e = $1
      end
    else
      e = value
    end
    if !e.nil?
      p = Fabulator::Expr::Parser.new
      value = p.parse(e, self)
    else
      value = Fabulator::Expr::Literal.new(value, [ FAB_NS, value =~ /^\d+$/ ? 'numeric' : value =~ /^\d*\.\d+$/ || value =~ /^\d+\.\d*$/ ? 'numeric' : 'string' ])
    end
    if opts[:static]
      value = value.run(self).collect{ |v| v.value }
      if value.empty?
        value = nil
      elsif value.size == 1
        value = value.first
      end
    end
  end

  value
end

#compile_action(e) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 363

def compile_action(e)
  ns = e.namespaces.namespace.href
  return unless Fabulator::TagLib.namespaces.include?(ns)
  Fabulator::TagLib.namespaces[ns].compile_action(e, self)
end

#compile_actions(xml) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 344

def compile_actions(xml)
  actions = Fabulator::Expr::StatementList.new
  return actions if xml.nil?

  local_ctx = self.merge(xml)
  xml.each_element do |e|
    ns = e.namespaces.namespace.href
    next unless Fabulator::TagLib.namespaces.include?(ns)
    if ns == FAB_NS && e.name == 'ensure'
      actions.add_ensure(local_ctx.compile_actions(e))
    elsif ns == FAB_NS && e.name == 'catch'
      actions.add_catch(local_ctx.compile_action(e))
    else
      actions.add_statement(local_ctx.compile_action(e)) # rescue nil)
    end
  end
  return actions
end

#compile_structural(e) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 387

def compile_structural(e)
  ns = e.namespaces.namespace.href
  return unless Fabulator::TagLib.namespaces.include?(ns)
  Fabulator::TagLib.namespaces[ns].compile_structural(e, self)
end

#compile_structurals(xml) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 369

def compile_structurals(xml)
  #local_ctx = self.merge(xml)
  structs = { }
  our_ns = xml.namespaces.namespace.href
  our_nom = xml.name
  xml.each_element do |e|
    ns = e.namespaces.namespace.href
    nom = e.name.to_sym
    allowed = (Fabulator::TagLib.namespaces[our_ns].structural_class(our_nom).accepts_structural?(ns, nom) rescue false)
    next unless allowed
    structs[ns] ||= { }
    structs[ns][nom] ||= [ ]
    structs[ns][nom] << self.compile_structural(e)
    structs[ns][nom] -= [ nil ]
  end
  return structs
end

#each_namespace(&block) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 174

def each_namespace(&block)
  if !@parent.nil?
    @parent.each_namespace do |k,v|
      yield k, v
    end
  end
  @ns.each_pair do |k,v|
     yield k, v
  end
end

#eval_expression(selection) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 185

def eval_expression(selection)
  if selection.is_a?(String)
    p = Fabulator::Expr::Parser.new
    selection = p.parse(selection, self)
  end

  if selection.nil?
    res = [ ]
  else
    # run selection against current context
    res = selection.run(self)
  end
  return res
end

#get_ns(n) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 164

def get_ns(n)
  return @ns[n] if @ns.has_key?(n)
  return @parent.get_ns(n) unless @parent.nil?
  return nil
end

#get_select(default = nil) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 122

def get_select(default = nil)
  self.attribute(FAB_NS, 'select', { :eval => true, :static => false, :default => default })
end

#get_values(ln = nil) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 279

def get_values(ln = nil)
  return [] if ln.nil?
  self.eval_expression(ln).collect{ |c| c.value} - [ nil ]
end

#get_var(v) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 144

def get_var(v)
  if !@variables.has_key?(v)
    if @run_time_parent.nil?
      if @parent.nil?
        nil
      else
        @parent.get_var(v)
      end
    else
      @run_time_parent.get_var(v)
    end
  else
    @variables[v]
  end
end

#in_context {|ctx| ... } ⇒ Object

Yields:

  • (ctx) 


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# File 'lib/fabulator/expr/context.rb', line 393

def in_context(&block)
  ctx = self.merge
  yield ctx
end

#last=(l) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 56

def last=(l)
  @last = !!l
end

#last? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fabulator/expr/context.rb', line 50

def last?
  return @last unless @last.nil?
  return @last if @run_time_parent.nil?
  return @run_time_parent.last?
end

#line_num ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 60

def line_num
  return @line_num unless @line_num.nil?
  return @parent.line_num unless @parent.nil?
  return 0
end

#merge(s = nil) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 76

def merge(s = nil)
  self.class.new(self, s)
end

#merge_data(d, p = nil) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 284

def merge_data(d,p = nil)
  # we have a hash or array based on root (r)
  if p.nil?
    root_context = [ self.root ]
  else
    root_context = self.traverse_path(p,true)
  end
  if root_context.size > 1
    # see if we need to prune
    new_rc = [ ]
    root_context.each do |c|
      if c.children.size == 0 && c.value.nil?
        c.parent.prune(c) if c.parent
      else
        new_rc << c
      end
    end
    if new_rc.size > 0
      raise "Unable to merge data into multiple places simultaneously"
    else
      root_context = new_rc
    end
  else
    root_context = root_context.first
  end
  if d.is_a?(Fabulator::Expr::Node)
    self.set_value(p, d)
  elsif d.is_a?(Array)
    node_name = root_context.name
    root_context = root_context.parent
    # get rid of empty children so we don't have problems later
    root_context.children.each do |c|
      if c.children.size == 0 && c.name == node_name && c.value.nil?
        c.parent.prune(c)
      end
    end
    d.each do |i|
      next if i.nil?
      if i.is_a?(Array) || i.is_a?(Hash)
        c = root_context.create_child(node_name)
        self.with_root(c).merge_data(i)
      else
        root_context.create_child(node_name, i)
      end
    end
  elsif d.is_a?(Hash)
    d.each_pair do |k,v|
      bits = k.split('.')
      c = self.with_root(root_context).traverse_path(bits,true).first
      if v.is_a?(Hash) || v.is_a?(Array) || v.is_a?(Fabulator::Expr::Node)
        self.with_root(c).merge_data(v)
      else
        c.value = v
      end
    end
  else
    c = root_context.parent.create_child(root_context.name, d)
  end
end

#position ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 66

def position
  return @position unless @position.nil?
  return @position if @run_time_parent.nil?
  return @run_time_parent.position
end

#position=(p) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 72

def position=(p)
  @position = p
end

#root ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 132

def root
  if @root.nil?
    return @run_time_parent.nil? ? 
           ( @parent.nil? ? nil : @parent.root ) : @run_time_parent.root
  end
  @root
end

#root=(r) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 140

def root=(r)
  @root = r
end

#run(action, autovivify = false) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 200

def run(action, autovivify = false)
  action.run(self, autovivify)
end

#run_filter(ns, name) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 414

def run_filter(ns, name)
  handler = Fabulator::TagLib.namespaces[ns]
  return [] if handler.nil?
  handler.run_filter(self, name)
end

#set_ns(n, h) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 170

def set_ns(n,h)
  @ns[n] = h
end

#set_value(p, v) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 235

def set_value(p, v)
  if p.is_a?(String) || v.is_a?(String)
    parser = Fabulator::Expr::Parser.new   
    p = parser.parse(p,self) if p.is_a?(String)
    v = parser.parse(v,self) if v.is_a?(String)
  end
      
  #return [] if p.nil?
  p = [ self.root ] if p.nil?

  p = [ p ] unless p.is_a?(Array)
        
  ret = [ ]

  p.each do |pp|
    tgts = pp.is_a?(Fabulator::Expr::Node) ? [ pp ] : pp.run(self, true)
    src = nil
    if !v.nil?
      src = v.is_a?(Fabulator::Expr::Node) ? [ v ] : v.run(self)
    end 

    tgts.each do |tgt|
      tgt.prune
      if src.nil? || src.empty?
        tgt.value = nil
        ret << tgt
      elsif src.size == 1
        tgt.copy(src.first)
        ret << tgt
      else
        pp = tgt.parent
        nom = tgt.name
        pp.prune(pp.children(nom))
        src.each do |s|
          tgt = pp.create_child(nom,nil)
          tgt.copy(s)
          ret << tgt
        end
      end
    end
  end
  ret
end

#set_var(v, vv) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 160

def set_var(v,vv)
  @variables[v] = vv
end

#traverse_path(path, autovivify = false) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 204

def traverse_path(path, autovivify = false)
  return [ self.root ] if path.nil? || path.is_a?(Array) && path.empty?
                       
  path = [ path ] unless path.is_a?(Array)

  current = [ self.root ]

  path.each do |c|
    set = [ ]
    current.each do |cc|
      if c.is_a?(String)
        cset = cc.children(c)
      else
        cset = c.run(self.with_root(cc), autovivify)
      end
      if cset.nil? || cset.empty?
        if autovivify
          if c.is_a?(String)
            cset = [ cc.create_child(c) ]
          else
            cset = [ c.create_node(cc) ]
          end
        end
      end
      set = set + cset
    end
    current = set
  end
  return current
end

#with(ctx2) {|ctx| ... } ⇒ Object

Yields:

  • (ctx) 


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# File 'lib/fabulator/expr/context.rb', line 398

def with(ctx2, &block)
  ctx = self.merge(ctx2)
  yield ctx
end

#with_root(r) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 126

def with_root(r)
  ctx = self.class.new(self)
  ctx.root = r
  ctx
end

#with_roots(items, &block) ⇒ Object 



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# File 'lib/fabulator/expr/context.rb', line 403

def with_roots(items, &block)
  idx = 1
  items.each do |i|
    ctx = self.with_root(i)
    ctx.position = idx
    ctx.last = idx == items.size
    yield ctx
    idx += 1
  end
end