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 = {}, rethrow_errors = false) ⇒ Context

Returns a new instance of Context.



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

def initialize(assigns = {}, registers = {}, rethrow_errors = false)
  @scopes     = [(assigns || {})]
  @registers  = registers
  @errors     = []
  @rethrow_errors = rethrow_errors
end

Instance Attribute Details

#errors ⇒ Object (readonly)

Returns the value of attribute errors.



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# File 'lib/liquid/context.rb', line 17

def errors
  @errors
end

#registers ⇒ Object (readonly)

Returns the value of attribute registers.



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# File 'lib/liquid/context.rb', line 17

def registers
  @registers
end

#scopes ⇒ Object (readonly)

Returns the value of attribute scopes.



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# File 'lib/liquid/context.rb', line 16

def scopes
  @scopes
end

Instance Method Details

#[](key) ⇒ Object 



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# File 'lib/liquid/context.rb', line 105

def [](key)
  resolve(key)
end

#[]=(key, value) ⇒ Object

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



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# File 'lib/liquid/context.rb', line 101

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

#add_filters(filters) ⇒ 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 33

def add_filters(filters)
  filters = [filters].flatten.compact

  filters.each do |f|
    raise ArgumentError, "Expected module but got: #{f.class}" unless f.is_a?(Module)
    strainer.extend(f)
  end
end

#handle_error(e) ⇒ Object 



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

def handle_error(e)
  errors.push(e)
  raise if @rethrow_errors

  case e
  when SyntaxError
    "Liquid syntax error: #{e.message}"
  else
    "Liquid error: #{e.message}"
  end
end

#has_key?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/liquid/context.rb', line 109

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

#invoke(method, *args) ⇒ Object 



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# File 'lib/liquid/context.rb', line 55

def invoke(method, *args)
  if strainer.respond_to?(method)
    strainer.__send__(method, *args)
  else
    raise FilterNotFound, "Filter '#{method}' not found"
  end
end

#merge(new_scopes) ⇒ Object

merge a hash of variables in the current local scope



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# File 'lib/liquid/context.rb', line 70

def merge(new_scopes)
  @scopes[0].merge!(new_scopes)
end

#pop ⇒ Object

pop from the stack. use Context#stack instead

Raises:



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# File 'lib/liquid/context.rb', line 75

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

#push ⇒ Object

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

Raises:



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# File 'lib/liquid/context.rb', line 64

def push
  raise StackLevelError, "Nesting too deep" if @scopes.length > 100
  @scopes.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 89

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

#strainer ⇒ Object 



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# File 'lib/liquid/context.rb', line 26

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