Class: DataProvider::Container

Inherits:
Object
  • Object
show all
Defined in:
lib/data_provider/container.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(_opts = {}) ⇒ Container

Returns a new instance of Container.



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# File 'lib/data_provider/container.rb', line 20

def initialize _opts = {}
  @options = _opts.is_a?(Hash) ? _opts : {}
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/data_provider/container.rb', line 18

def options
  @options
end

Instance Method Details

#add(container) ⇒ Object 



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# File 'lib/data_provider/container.rb', line 152

def add(container)
  # make a copy and add the container to that 
  give({}).add!(container)
end

#add!(container) ⇒ Object

adds all the providers defined in the given module to this class



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# File 'lib/data_provider/container.rb', line 133

def add!(container)
  ### add container's providers ###
  # internally providers are added in reverse order (last one first)
  # so at runtime you it's easy and fast to grab the latest provider
  # so when adding now, we have to reverse the providers to get them in the original order
  container.providers.reverse.each do |definition|
    add_provider(*definition)
  end

  ### add container's provides (simple providers) ###
  self.provides(container.provides)

  ### fallback provider ###
  @fallback_provider = container.fallback_provider.block if container.fallback_provider

  ### add container's data ###
  give!(container.data)
end

#add_scoped(container, _options = {}) ⇒ Object

adds all the providers defined in the given module to this class, but turns their identifiers into array and prefixes the array with the :scope option



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# File 'lib/data_provider/container.rb', line 181

def add_scoped container, _options = {}
  copy.add_scoped!(container, _options)
end

#add_scoped!(container, _options = {}) ⇒ Object

adds all the providers defined in the given module to this class, but turns their identifiers into array and prefixes the array with the :scope option



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# File 'lib/data_provider/container.rb', line 159

def add_scoped! container, _options = {}
  ### add container's providers ###
  container.providers.reverse.each do |definition|
    identifier = [definition[0]].flatten
    identifier = [_options[:scope]].flatten.compact + identifier if _options[:scope]
    add_provider(*([identifier]+definition[1..-1]))
  end

  ### add container's provides (simple providers) ###
  container.provides.each_pair do |key, value|
    provides(([_options[:scope]].flatten.compact + [key].flatten.compact) => value)
  end

  ### fallback provider ###
  @fallback_provider = container.fallback_provider.block if container.fallback_provider

  ### add container's data ###
  give!(container.data)
end

#copy ⇒ Object

Data-related methods



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# File 'lib/data_provider/container.rb', line 189

def copy
  c = self.class.new
  c.add!(self)
end

#data ⇒ Object 



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# File 'lib/data_provider/container.rb', line 194

def data
  @data || {}
end

#fallback_provider ⇒ Object 



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# File 'lib/data_provider/container.rb', line 65

def fallback_provider
  block = @fallback_provider
  block.nil? ? nil : Provider.new(nil, nil, block)
end

#fallback_provider? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/data_provider/container.rb', line 70

def fallback_provider?
  !fallback_provider.nil?
end

#give(_data = {}) ⇒ Object Also known as: add_scope, add_data 



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# File 'lib/data_provider/container.rb', line 198

def give(_data = {})
  copy.give!(_data)
end

#give!(_data = {}) ⇒ Object Also known as: add_scope!, add_data! 



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# File 'lib/data_provider/container.rb', line 205

def give!(_data = {})
  @data ||= {}
  @data.merge!(_data)
  return self
end

#given(param_name) ⇒ Object Also known as: get_data 



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# File 'lib/data_provider/container.rb', line 214

def given(param_name)
  return data[param_name] if got?(param_name)
  logger.debug "Data provider expected missing data with identifier: #{param_name.inspect}"
  # TODO: raise?
  return nil
end

#got?(param_name) ⇒ Boolean Also known as: has_data?

Returns:

  • (Boolean) 


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# File 'lib/data_provider/container.rb', line 224

def got?(param_name)
  data.has_key?(param_name)
end

#has_provider?(identifier) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/data_provider/container.rb', line 34

def has_provider?(identifier)
  (provides.keys.find{|k| k == identifier} || get_provider(identifier)) != nil
end

#has_providers_with_scope?(args) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/data_provider/container.rb', line 38

def has_providers_with_scope?(args)
  scope = args.is_a?(Array) ? args : [args]
  provider_identifiers.find{|id| id.is_a?(Array) && id.length > scope.length && id[0..(scope.length-1)] == scope} != nil
end

#logger ⇒ Object 



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# File 'lib/data_provider/container.rb', line 24

def logger
  @logger ||= options[:logger] || Logger.new(STDOUT).tap do |lger|
    lger.level = Logger::WARN
  end
end

#missing_provider ⇒ Object 



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# File 'lib/data_provider/container.rb', line 230

def missing_provider
  @missing_provider
end

#provider(identifier, opts = {}, &block) ⇒ Object 



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# File 'lib/data_provider/container.rb', line 30

def provider identifier, opts = {}, &block
  add_provider(identifier, opts, block_given? ? block : nil)
end

#provider_id ⇒ Object 



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# File 'lib/data_provider/container.rb', line 242

def provider_id
  provider_stack.last
end

#provider_identifiers ⇒ Object 



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# File 'lib/data_provider/container.rb', line 43

def provider_identifiers
  (provides.keys + providers.map(&:first)).compact.uniq
end

#provider_missing(&block) ⇒ Object 



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# File 'lib/data_provider/container.rb', line 60

def provider_missing &block
  raise "DataProvider::Base#provider_missing expects a block as an argument" if !block_given?
  @fallback_provider = block
end

#provider_stack ⇒ Object 



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# File 'lib/data_provider/container.rb', line 238

def provider_stack
  (@stack || []).clone
end

#providers ⇒ Object 



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# File 'lib/data_provider/container.rb', line 56

def providers
  @providers || []
end

#provides(_provides = nil) ⇒ Object

provides, when called with a hash param, will define ‘simple providers’ (providers with a simple, static value). When called without a param (or nil) it returns the current cumulative ‘simple providers’ hash



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# File 'lib/data_provider/container.rb', line 50

def provides _provides = nil
  return @provides || {} if _provides.nil?
  add_provides _provides
  return self
end

#scope ⇒ Object 



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# File 'lib/data_provider/container.rb', line 250

def scope
  scopes.last || []
end

#scoped_take(id) ⇒ Object 



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# File 'lib/data_provider/container.rb', line 234

def scoped_take(id)
  take(scope + [id].flatten)
end

#scopes ⇒ Object 



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# File 'lib/data_provider/container.rb', line 246

def scopes
  provider_stack.map{|provider_id| provider_id.is_a?(Array) ? provider_id[0..-2] : []}
end

#take(id, opts = {}) ⇒ Object

Raises:



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# File 'lib/data_provider/container.rb', line 74

def take(id, opts = {})
  logger.debug "DataProvider::Container#take with id: #{id.inspect}"

  # first try the simple providers
  if provides.has_key?(id)
    provider = provides[id]
    return provider.is_a?(Proc) ? provider.call : provider
  end

  # try to get a provider object
  provider = get_provider(id)
  if provider
    @stack = (@stack || []) + [id]
    result = (opts[:scope] || self).instance_eval(&provider.block) 
    @stack.pop
    # execute provider object's block within the scope of self
    return result
  end

  # try to get a scoped provider object
  if scope.length > 0
    scoped_id = [scope, id].flatten
    provider = get_provider(scoped_id)
    if provider
      @stack = (@stack || []) + [scoped_id]
      result = (opts[:scope] || self).instance_eval(&provider.block) 
      @stack.pop
      # execute provider object's block within the scope of self
      return result
    end
  end

  # couldn't find requested provider, let's see if there's a fallback
  if provider = fallback_provider
    # temporarily set the @missing_provider instance variable, so the
    # fallback provider can use it through the missing_provider private method
    @missing_provider = id
    @stack = (@stack || []) + [id]
    result = (opts[:scope] || self).instance_eval(&provider.block) # provider.block.call # with the block.call method the provider can't access private methods like missing_provider
    @stack.pop # = nil
    @missing_provider = nil
    return result
  end

  # no fallback either? Time for an error
  raise ProviderMissingException.new(:provider_id => id) 
end

#try_take(id, opts = {}) ⇒ Object 



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# File 'lib/data_provider/container.rb', line 122

def try_take(id, opts = {})
  return take(id, opts) if self.has_provider?(id) || self.fallback_provider?
  logger.debug "Try for missing provider: #{id.inspect}"
  return nil
end