Class: Pinion::Conversion

Inherits:
Object
  • Object
show all
Defined in:
lib/pinion/conversion.rb

Overview

A conversion describes how to convert certain types of files and create asset links for them. Conversions.create() provides a tiny DSL for defining new conversions

Constant Summary collapse

@@conversions = 
{}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(from_type, to_type) ⇒ Conversion

Returns a new instance of Conversion.



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# File 'lib/pinion/conversion.rb', line 26

def initialize(from_type, to_type)
  @loaded = false
  @from_type = from_type
  @to_type = to_type
  @gem_required = nil
  @conversion_fn = nil
  @watch_fn = Proc.new {} # Don't do anything by default
  @context = {}
end

Instance Attribute Details

#from_type ⇒ Object (readonly)

Returns the value of attribute from_type.



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# File 'lib/pinion/conversion.rb', line 24

def from_type
  @from_type
end

#gem_required ⇒ Object (readonly)

Returns the value of attribute gem_required.



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# File 'lib/pinion/conversion.rb', line 24

def gem_required
  @gem_required
end

#to_type ⇒ Object (readonly)

Returns the value of attribute to_type.



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# File 'lib/pinion/conversion.rb', line 24

def to_type
  @to_type
end

Class Method Details

.[](from_and_to) ⇒ Object 



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# File 'lib/pinion/conversion.rb', line 11

def self.[](from_and_to) @@conversions[from_and_to] end

.add_watch_directory(path) ⇒ Object 



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# File 'lib/pinion/conversion.rb', line 13

def self.add_watch_directory(path) @@conversions.values.each { |c| c.add_watch_directory(path) } end

.conversions_for(to) ⇒ Object 



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# File 'lib/pinion/conversion.rb', line 12

def self.conversions_for(to) @@conversions.values.select { |c| c.to_type == to } end

.create(from_and_to, &block) ⇒ Object 



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# File 'lib/pinion/conversion.rb', line 14

def self.create(from_and_to, &block)
  unless from_and_to.is_a?(Hash) && from_and_to.size == 1
    raise Error, "Unexpected argument to Conversion.create: #{from_and_to.inspect}"
  end
  conversion = Conversion.new *from_and_to.to_a[0]
  conversion.instance_eval &block
  conversion.verify
  @@conversions[conversion.signature] = conversion
end

Instance Method Details

#add_watch_directory(path) ⇒ Object 



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# File 'lib/pinion/conversion.rb', line 47

def add_watch_directory(path) @watch_fn.call(path, @context) end

#convert(file_contents) ⇒ Object 



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# File 'lib/pinion/conversion.rb', line 43

def convert(file_contents)
  require_dependency
  @conversion_fn.call(file_contents, @context)
end

#render(&block) ⇒ Object 



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# File 'lib/pinion/conversion.rb', line 38

def render(&block) @conversion_fn = block end

#require_gem(gem_name) ⇒ Object

DSL methods



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# File 'lib/pinion/conversion.rb', line 37

def require_gem(gem_name) @gem_required = gem_name end

#signature ⇒ Object

Instance methods



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# File 'lib/pinion/conversion.rb', line 42

def signature() { @from_type => @to_type } end

#verify ⇒ Object 



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# File 'lib/pinion/conversion.rb', line 49

def verify
  unless [@from_type, @to_type].all? { |s| s.is_a? Symbol }
    raise Error, "Expecting symbol key/value but got #{from_and_to.inspect}"
  end
  unless @conversion_fn
    raise Error, "Must provide a conversion function with convert { |file_contents| ... }."
  end
end

#watch(&block) ⇒ Object 



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# File 'lib/pinion/conversion.rb', line 39

def watch(&block) @watch_fn = block end