Class: Liquid::Context

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

Overview

Context keeps the variable stack and resolves variables, as well as keywords

context['variable'] = 'testing'
context['variable'] #=> 'testing'
context['true']     #=> true
context['10.2232']  #=> 10.2232

context.stack do 
   context['bob'] = 'bobsen'
end

context['bob']  #=> nil  class Context

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(assigns = {}, registers = nil) ⇒ Context

Returns a new instance of Context.



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# File 'lib/liquid/context.rb', line 22

def initialize(assigns = {}, registers = nil)
  @assigns = [assigns]
  @registers = registers || {}
end

Instance Attribute Details

#assigns ⇒ Object (readonly)

Returns the value of attribute assigns.



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

def assigns
  @assigns
end

#registers ⇒ Object

Returns the value of attribute registers.



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# File 'lib/liquid/context.rb', line 20

def registers
  @registers
end

Instance Method Details

#[](key) ⇒ Object 



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

def [](key)
  resolve(key)
end

#[]=(key, value) ⇒ Object

Only allow String, Numeric, Hash, Array or Liquid::Drop



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# File 'lib/liquid/context.rb', line 83

def []=(key, value)
  @assigns[0][key] = value
end

#add_filters(filter) ⇒ Object

adds filters to this context. this does not register the filters with the main Template object. see Template.register_filter for that



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# File 'lib/liquid/context.rb', line 34

def add_filters(filter)
  return unless filter.is_a?(Module)
  strainer.extend(filter)
end

#has_key?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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

def has_key?(key)
  resolve(key) != nil
end

#invoke(method, *args) ⇒ Object 



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# File 'lib/liquid/context.rb', line 39

def invoke(method, *args)
  if strainer.respond_to?(method)
    strainer.__send__(method, *args)
  else
    return args[0]
  end        
end

#merge(new_assigns) ⇒ Object

merge a hash of variables in the current local scope



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# File 'lib/liquid/context.rb', line 53

def merge(new_assigns)
  @assigns[0].merge!(new_assigns)
end

#pop ⇒ Object

pop from the stack. use Context#stack instead

Raises:



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# File 'lib/liquid/context.rb', line 58

def pop
  raise ContextError if @assigns.size == 1 
  @assigns.shift
end

#push ⇒ Object

push new local scope on the stack. use Context#stack instead



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# File 'lib/liquid/context.rb', line 48

def push
  @assigns.unshift({})
end

#stack(&block) ⇒ Object

pushes a new local scope on the stack, pops it at the end of the block

Example:

context.stack do 
   context['var'] = 'hi'
end
context['var]  #=> nil



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# File 'lib/liquid/context.rb', line 72

def stack(&block)
  push
  begin
    result = yield
  ensure 
    pop
  end
  result      
end

#strainer ⇒ Object 



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

def strainer
  @strainer ||= Strainer.create(self)
end