Class: HexaPDF::Configuration

Inherits:
Object
  • Object
show all
Defined in:
lib/hexapdf/configuration.rb

Overview

Manages both the global and document specific configuration options for HexaPDF.

Overview

HexaPDF allows detailed control over many aspects of PDF manipulation. If there is a need to use a certain default value somewhere, it is defined as a configuration option so that it can easily be changed.

Some options are defined as global options because they are needed on the class level - see HexaPDF::GlobalConfiguration. Other options can be configured for individual documents as they allow to fine-tune some behavior - see HexaPDF::DefaultDocumentConfiguration.

A configuration option name is dot-separted to provide a hierarchy of option names. For example, io.chunk_size.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Configuration

Creates a new Configuration object using the provided hash argument.



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# File 'lib/hexapdf/configuration.rb', line 66

def initialize(options = {})
  @options = options
end

Class Method Details

.with_defaults(values = {}) ⇒ Object

Creates a new document specific Configuration object by merging the values into the default configuration object.



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# File 'lib/hexapdf/configuration.rb', line 61

def self.with_defaults(values = {})
  DefaultDocumentConfiguration.merge(values)
end

Instance Method Details

#[](name) ⇒ Object

Returns the value for the configuration option name.



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# File 'lib/hexapdf/configuration.rb', line 77

def [](name)
  options[name]
end

#[]=(name, value) ⇒ Object

Uses value as the value for the configuration option name.



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# File 'lib/hexapdf/configuration.rb', line 82

def []=(name, value)
  options[name] = value
end

#constantize(name, *keys) ⇒ Object

:call-seq:

config.constantize(name, *keys)                  -> constant
config.constantize(name, *keys) {|name| block}   -> obj

Returns the constant the option name is referring to. If keys are provided and the value of the option name responds to #dig, the constant to which the keys refer is returned.

If no constant can be found and no block is provided, an error is raised. If a block is provided it is called with the option name and its result will be returned.

config.constantize('encryption.aes')      #=> HexaPDF::Encryption::FastAES
config.constantize('filter.map', :Fl)     #=> HexaPDF::Filter::FlateDecode



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# File 'lib/hexapdf/configuration.rb', line 121

def constantize(name, *keys)
  data = self[name]
  data = data.dig(*keys) if data.respond_to?(:dig)
  (data = ::Object.const_get(data) rescue nil) if data.kind_of?(String)
  if data.nil? && block_given?
    data = yield(name)
  elsif data.nil?
    raise HexaPDF::Error, "Error getting constant for configuration option '#{name}'" +
      (keys.empty? ? "" : " and keys '#{keys.join(', ')}'")
  end
  data
end

#key?(name) ⇒ Boolean Also known as: option?

Returns true if the given option exists.

Returns:

  • (Boolean) 


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# File 'lib/hexapdf/configuration.rb', line 71

def key?(name)
  options.key?(name)
end

#merge(config) ⇒ Object

Returns a new Configuration object containing the options from the given configuration object (or hash) and this configuration object.

If a key already has a value in this object, its value is overwritten by the one from config. However, hash values are merged instead of being overwritten. Array values are duplicated.



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# File 'lib/hexapdf/configuration.rb', line 92

def merge(config)
  config = (config.kind_of?(self.class) ? config.options : config)
  merged_config = options.each_with_object({}) do |(key, old), conf|
    new = config[key]
    conf[key] = if old.kind_of?(Hash) && new.kind_of?(Hash)
                  old.merge(new)
                elsif new.kind_of?(Array) || old.kind_of?(Array)
                  (new || old).dup
                elsif config.key?(key)
                  new
                else
                  old
                end
  end
  self.class.new(merged_config)
end