Class: ZTK::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/ztk/base.rb

Overview

Base Class

This is the base class inherited by most of the other classes in this library. It provides a standard set of features to control STDOUT, STDERR and STDIN, a configuration mechanism and logging mechanism.

You should never interact with this class directly; you should inherit it and extend functionality as appropriate.

Author:

Direct Known Subclasses

Background, Command, GoogleChart::Base, Parallel, Report, SSH, TCPSocketCheck, UI

Class Method Summary (collapse)

Instance Method Summary (collapse)

Constructor Details

- (Base) initialize(config = {}, override = {})

Returns a new instance of Base

Parameters:

  • config (Hash) (defaults to: {}) —

    Initial configuration hash.

  • override (Hash) (defaults to: {}) —

    Override configuration hash.



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# File 'lib/ztk/base.rb', line 75

def initialize(config={}, override={})
  @config = Base.build_config(config, override)
end

Class Method Details

+ (Object) build_config(config = {}, override = {})

Builds Configuration Object

Builds an OpenStruct backed configuration object.

Parameters:

  • config (Hash) (defaults to: {}) —

    Configuration options hash.

  • override (Hash) (defaults to: {}) —

    Override configuration hash.

Options Hash (config):

  • :ui (ZTK::UI) —

    Instance of ZTK:UI to be used for console IO and logging.



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# File 'lib/ztk/base.rb', line 32

def build_config(config={}, override={})
  config = OpenStruct.new({
    :ui => ::ZTK::UI.new
  }.merge(hash_config(config)).merge(hash_config(override)))

  config.ui.logger.debug { "config=#{config.send(:table).inspect}" }

  config
end

+ (Object) hash_config(config = {})

Hash Configuration

Ensure a configuration is of object type Hash. Since we use OpenStructs we need to convert back to hash from time to time.



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# File 'lib/ztk/base.rb', line 46

def hash_config(config={})
  if config.is_a?(OpenStruct)
    config.send(:table)
  else
    config
  end
end

+ (Object) log_and_raise(logger, exception, message, shift = 1)

Logs an exception and then raises it.

Parameters:

  • logger (Logger) —

    An instance of a class based off the Ruby Logger class.

  • exception (Exception) —

    The exception class to raise.

  • message (String) —

    The message to display with the exception.

  • shift (Integer) (defaults to: 1) —

    (1) How many places to shift the caller stack in the log statement.

Raises:

  • (exception) 


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# File 'lib/ztk/base.rb', line 62

def log_and_raise(logger, exception, message, shift=1)
  if logger.is_a?(ZTK::Logger)
    logger.shift(:fatal, shift) { "EXCEPTION: #{exception.inspect} - #{message.inspect}" }
  else
    logger.fatal { "EXCEPTION: #{exception.inspect} - #{message.inspect}" }
  end
  raise exception, message
end

Instance Method Details

- (OpenStruct) config {|config| ... }

Configuration OpenStruct accessor method.

If no block is given, the method will return the configuration OpenStruct object. If a block is given, the block is yielded with the configuration OpenStruct object.

Yield Parameters:

  • config (OpenStruct) —

    The configuration OpenStruct object.

Returns:

  • (OpenStruct) —

    The configuration OpenStruct object.



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# File 'lib/ztk/base.rb', line 87

def config(&block)
  if block_given?
    block.call(@config)
  else
    @config
  end
end

- (Object) direct_log(log_level) { ... }

Direct logging method.

This method provides direct writing of data to the current log device. This is mainly used for pushing STDOUT and STDERR into the log file in ZTK::SSH and ZTK::Command, but could easily be used by other classes.

The value returned in the block is passed down to the logger specified in the classes configuration.

Parameters:

  • log_level (Symbol) —

    This should be any one of [:debug, :info, :warn, :error, :fatal].

Yields:

  • No value is passed to the block.

Yield Returns:

  • (String) —

    The message to log.



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# File 'lib/ztk/base.rb', line 119

def direct_log(log_level, &blocK)
  @config.ui.logger.nil? and raise BaseError, "You must supply a logger for direct logging support!"

  if !block_given?
    log_and_raise(BaseError, "You must supply a block to the log method!")
  elsif (@config.ui.logger.level <= ::Logger.const_get(log_level.to_s.upcase))
    @config.ui.logger << ZTK::ANSI.uncolor(yield)
  end
end

- (Object) log_and_raise(exception, message, shift = 2)

Logs an exception and then raises it.

Parameters:

  • exception (Exception) —

    The exception class to raise.

  • message (String) —

    The message to display with the exception.

  • shift (Integer) (defaults to: 2) —

    (2) How many places to shift the caller stack in the log statement.

See Also:



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# File 'lib/ztk/base.rb', line 103

def log_and_raise(exception, message, shift=2)
  Base.log_and_raise(config.ui.logger, exception, message, shift)
end