Module: Denko::Behaviors::Reader

Includes:
Callbacks
Included in:
AnalogIO::ADS111X, AnalogIO::Input, Poller, DigitalIO::Input, EEPROM::BuiltIn, I2C::Bus, I2C::Peripheral, OneWire::Bus, SPI::BitBang, SPI::Bus, Sensor::HTU21D
Defined in:
lib/denko/behaviors/reader.rb

Instance Attribute Summary

Attributes included from Callbacks

#callback_mutex

Instance Method Summary collapse

Methods included from Callbacks

#add_callback, #callbacks, #initialize, #pre_callback_filter, #remove_callback, #update

Methods included from State

#initialize, #state

Instance Method Details

#_read ⇒ Object

Raises:

  • (NotImplementedError) 


44
45
46
47
 
# File 'lib/denko/behaviors/reader.rb', line 44

def _read
  raise NotImplementedError
    .new("#{self.class.name}#_read is not defined.")
end

#read(*args, **kwargs, &block) ⇒ Object

Defalt behavior for #read is to delegate to #_read. Define #_read in including classes.



10
11
12
 
# File 'lib/denko/behaviors/reader.rb', line 10

def read(*args, **kwargs, &block)
  read_using(self.method(:_read), *args, **kwargs, &block)
end

#read_using(reader, *args, **kwargs, &block) ⇒ Object

Take a proc/lambda/method as the first agrument and use it to read. Arguments are passed through, allowing dynamic read methods to be defined. Eg. send commands (in args) to a bus, then wait for data read back.

Block given is added as a one-time callback in the :read key, and the curent thread waits until data is received. Returns the result of calling #pre_callback_filter with the data.



23
24
25
26
27
28
29
30
31
32
33
34
35
 
# File 'lib/denko/behaviors/reader.rb', line 23

def read_using(reader, *args, **kwargs, &block)
  add_callback(:read, &block) if block_given?

  return_value = nil
  add_callback(:read) do |filtered_data|
    return_value = filtered_data
  end
  
  reader.call(*args, **kwargs)
  wait_for_read

  return_value
end

#wait_for_read ⇒ Object 



37
38
39
40
41
42
 
# File 'lib/denko/behaviors/reader.rb', line 37

def wait_for_read
  loop do
    break if !callbacks[:read]
    sleep 0.001
  end
end