Class: H2o::Context

Inherits:
Object show all
Defined in:
lib/h2o/context.rb

Instance Method Summary collapse

Constructor Details

#initialize(context = {}) ⇒ Context

Returns a new instance of Context.



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# File 'lib/h2o/context.rb', line 4

def initialize(context ={})
  @stack = [context]
  @filter_env = Filters.build(self)
end

Instance Method Details

#[](name) ⇒ Object

doing a reverse lookup FIXME: need to double check this, also changed Block#add_layer in reverse order



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# File 'lib/h2o/context.rb', line 11

def [](name)
  @stack.each do |layer|
    value = layer[name]
    return value unless value.nil?
  end
  nil
end

#[]=(name, value) ⇒ Object 



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# File 'lib/h2o/context.rb', line 19

def []=(name, value)
  @stack.first[name] = value
end

#apply_filters(object, filters) ⇒ Object 



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# File 'lib/h2o/context.rb', line 91

def apply_filters(object, filters)
  filters.each do |filter|
    name, *args = filter

    raise FilterError, "Filter(#{name}) not found" unless @filter_env.respond_to?(name)
    
    args.map! do |arg|
      if arg.kind_of? Symbol
        resolve(arg)
      else
        arg
      end
    end

    object = @filter_env.__send__(name, object, *args)
  end
  object
end

#has_key?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/h2o/context.rb', line 87

def has_key?(key)
  !send(:[], key).nil?
end

#pop ⇒ Object 



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# File 'lib/h2o/context.rb', line 23

def pop
  @stack.shift if @stack.size > 1
end

#push(hash = {}) ⇒ Object 



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# File 'lib/h2o/context.rb', line 27

def push(hash = {})
  @stack.unshift hash
end

#resolve(name) ⇒ Object 



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# File 'lib/h2o/context.rb', line 42

def resolve(name)
  return name unless name.is_a? Symbol
  
  object = self
  parts = name.to_s.split('.')
  part_sym = nil

  parts.each do |part|
    part_sym = part.to_sym

    # Hashes
    if object.respond_to?(:has_key?) && (object.has_key?(part_sym) || object.has_key?(part))
        result = object[part_sym] || object[part]
        # Proc object with extra caution
        begin
          result = object[part_sym] = result.call if result.is_a?(Proc) && object.respond_to?(:[]=)
        rescue
          return nil
        end
        object = result.to_h2o
  
    # Array and Hash like objects
    elsif part.match(/^-?\d+$/)
      if (object.respond_to?(:has_key?) || object.respond_to?(:fetch)) && value = object[part.to_i]
        object = value.to_h2o
      else
        return nil
      end
    
    # H2o::DataObject Type
    elsif (object.is_a?(DataObject) || object.class.h2o_safe_methods && object.class.h2o_safe_methods.include?(part_sym) )&& \
          object.respond_to?(part_sym)
      object = object.__send__(part_sym).to_h2o
    
    # Sweet array shortcuts
    elsif object.respond_to?(part_sym) && [:first, :length, :size, :last].include?(part_sym)
      object = object.__send__(part_sym).to_h2o
    else
      return nil
    end
  end
  
  object
end

#stack ⇒ Object 



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# File 'lib/h2o/context.rb', line 31

def stack
  result = nil
  push
  begin
    result = yield
  ensure
    pop
  end
  result
end