Module: PageTemplate::NamespaceItem

Included in:
Namespace, Parser, Template
Defined in:
lib/PageTemplate/parser.rb

Overview

A Namespace object consists of three things:

parent: A parent object to get a value from if the namespace does not ‘know’ a value.

object: An object is a hash or list that contains the values that this namespace will refer to. It may also be an object, in which case, its methods are treated as a hash, with respond_to? and send()

Cache: A cache ensures that a method on an object will only be called once.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#object ⇒ Object

Returns the value of attribute object.



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# File 'lib/PageTemplate/parser.rb', line 23

def object
  @object
end

#parent ⇒ Object

Returns the value of attribute parent.



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# File 'lib/PageTemplate/parser.rb', line 23

def parent
  @parent
end

Instance Method Details

#clear ⇒ Object Also known as: clear_cache

Clears the cache



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# File 'lib/PageTemplate/parser.rb', line 26

def clear
  @values = Hash.new
end

#delete(key) ⇒ Object

Removes an entry from the Namespace



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# File 'lib/PageTemplate/parser.rb', line 131

def delete(key)
  @values.delete(key)
end

#get(val, clean_rescue = true) ⇒ Object Also known as: []

Returns the first value found for key in the nested namespaces. Returns nil if no value is found.

Values are checked for in this order through each level of namespace:

  • level.key

  • level.key()

  • level

If a value is not found in any of the nested namespaces, get() searches for the key in the global namespace.

If val is a dot-separated list of words, then ‘key’ is the first part of it. The remainder of the words are sent to key (and further results) to premit accessing attributes of objects.



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# File 'lib/PageTemplate/parser.rb', line 54

def get(val,clean_rescue=true)
  args = parser.args
  @values ||= {}
  @object ||= nil

  clean_rescue = !args['raise_on_error'] if clean_rescue

  val.gsub!(/[#{Regexp.escape(parser.method_separators)}]/,'.')

  key, rest = val.split(/\./, 2)

  value = case
  when @values.has_key?(key)
    @values[key]
  when @values.has_key?(key.to_sym)
    @values[key.to_sym]
  when !@object
    if @parent
      @parent.get(val)
    else
      nil
    end
  when @object.respond_to?(:has_key?)
    if @object.has_key?(key)
      @values[key] = @object[key]
    else
      return @parent.get(val) if @parent
      nil
    end
  when @object.respond_to?(sym = key.to_sym)
    @values[key] = @object.send(sym)
  when key == '__ITEM__'
    @object
  when @parent
    return @parent.get(val)
  else
    nil
  end

  if rest
    names = [key]
    rest.split(/\./).each do |i|
      names << i
      name = names.join('.')
      begin
        value = if @values.has_key?(name)
          @values[name]
        else
          @values[name] = value = case
          when @values.has_key?(name)
            @values[name]
          when value.respond_to?(:has_key?) # Hash
            value[i]
          when value.respond_to?(:[]) && i =~ /^\d+$/ # Array
            value[i.to_i]
          when value.respond_to?(i) # Just a method
            value.send(i)
          else
            nil
          end
        end
      rescue NoMethodError => er
        return nil
      end
    end
  end
  value
rescue Exception => e
  if clean_rescue
    "[ Error: #{e.message} ]"
  else
    raise e
  end
end

#parser ⇒ Object

parser: most namespace objects won’t be a parser, but pass this query up to the parser object.



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# File 'lib/PageTemplate/parser.rb', line 137

def parser
  if @parent
    @parent.parser
  else
    Parser.recent_parser
  end
end

#set(key, value) ⇒ Object Also known as: []=

Saves a variable key as the string value in the global namespace.



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# File 'lib/PageTemplate/parser.rb', line 33

def set(key, value)
  @values ||= {}
  @values[key] = value
end

#true?(flag) ⇒ Boolean

A convenience method to test whether a variable has a true value. Returns nil if flag is not found in the namespace, or flag has a nil value attached to it.

Returns:

  • (Boolean) 


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# File 'lib/PageTemplate/parser.rb', line 148

def true?(flag)
  args = parser.args
  val = get(flag,false)
  case
  when ! val
    false
  when args['empty_is_true']
    true
  when val.respond_to?(:empty?)
    ! val.empty?
  else
    true
  end
rescue Exception => er
  false
end