Class: OpenWFE::Iterator

Inherits:
Object
  • Object
show all
Defined in:
lib/openwfe/expressions/fe_iterator.rb

Overview

Iterator instances keep track of the position of an iteration. This class is meant to be used both by <iterator> and <concurrent-iterator>.

Constant Summary collapse

ITERATOR_COUNT = 
"__ic__"
ITERATOR_POSITION = 
"__ip__"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(iterator_expression, workitem) ⇒ Iterator

Builds a new iterator, serving a given iterator_expression. The second parameter is the workitem (as applied to the iterator expression).



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 162

def initialize (iterator_expression, workitem)

    @to_field = iterator_expression\
        .lookup_attribute(:to_field, workitem)
    @to_variable = iterator_expression\
        .lookup_attribute(:to_variable, workitem)

    @value_separator = iterator_expression\
        .lookup_attribute(:value_separator, workitem)

    @value_separator = /,\s*/ unless @value_separator

    @iteration_index = 0

    #raw_list = iterator_expression.lookup_vf_attribute(
    #    workitem, :value, :prefix => :on)
    #raw_list ||= iterator_expression.lookup_attribute(:on, workitem)

    raw_list = 
        iterator_expression.lookup_vf_attribute(
            workitem, :value, :prefix => :on) ||
        iterator_expression.lookup_vf_attribute(
            workitem, nil, :prefix => :on)

    @iteration_list = extract_iteration_list raw_list

    workitem.attributes[ITERATOR_COUNT] = @iteration_list.length
end

Instance Attribute Details

#iteration_index ⇒ Object

Returns the value of attribute iteration_index.



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 151

def iteration_index
  @iteration_index
end

#iteration_list ⇒ Object

Returns the value of attribute iteration_list.



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 152

def iteration_list
  @iteration_list
end

#to_field ⇒ Object

Returns the value of attribute to_field.



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 153

def to_field
  @to_field
end

#to_variable ⇒ Object

Returns the value of attribute to_variable.



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 154

def to_variable
  @to_variable
end

#value_separator ⇒ Object

Returns the value of attribute value_separator.



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 155

def value_separator
  @value_separator
end

Instance Method Details

#has_next? ⇒ Boolean

Has the iteration a next element ?

Returns:

  • (Boolean) 


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# File 'lib/openwfe/expressions/fe_iterator.rb', line 194

def has_next?

    @iteration_index < @iteration_list.size
end

#index ⇒ Object

The current index (whereas @iteration_index already points to the next element).



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 253

def index

    @iteration_index - 1
end

#jump(workitem, index) ⇒ Object

Jumps to a given position in the iterator



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 228

def jump (workitem, index)

    index = if index < 0
        0
    elsif index >= @iteration_list.size
        @iteration_list.size
    else
        index
    end

    position_at workitem, index
end

#next(workitem) ⇒ Object

Prepares the iterator expression and the workitem for the next iteration.



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 212

def next (workitem)

    position_at workitem, @iteration_index
end

#rewind(workitem) ⇒ Object

Positions the iterator back at position 0.



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 220

def rewind (workitem)

    position_at workitem, 0
end

#size ⇒ Object

Returns the size of this iterator, or rather, the size of the underlying iteration list.



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 203

def size

    @iteration_list.size
end

#skip(workitem, offset) ⇒ Object

Jumps a certain number of positions in the iterator.



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# File 'lib/openwfe/expressions/fe_iterator.rb', line 244

def skip (workitem, offset)

    jump workitem, @iteration_index + offset
end