Class: Rapporteur::Checker

Inherits:
Object
  • Object
show all
Extended by:
CheckerDeprecations
Includes:
ActiveModel::Validations
Defined in:
lib/rapporteur/checker.rb

Overview

The center of the Rapporteur library, Checker manages holding and running the custom checks, holding any application error messages, and provides the controller with that data for rendering.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Checker

Returns a new instance of Checker.



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# File 'lib/rapporteur/checker.rb', line 13

def initialize
  @messages = Hash.new
  @checks = Set.new
  reset
end

Instance Method Details

#add_check(object_or_nil_with_block = nil, &block) ⇒ Object

Public: Add a pre-built or custom check to your status endpoint. These checks are used to test the state of the world of the application, and need only respond to ‘#call`.

Once added, the given check will be called and passed an instance of this checker. If everything is good, do nothing! If there is a problem, use ‘add_error` to add an error message to the checker.

Examples

Rapporteur.add_check { |checker|
  checker.add_error("Bad luck.") if rand(2) == 1
}

Returns self. Raises ArgumentError if the given check does not respond to call.



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# File 'lib/rapporteur/checker.rb', line 37

def add_check(object_or_nil_with_block=nil, &block)
  if block_given?
    @checks << block
  elsif object_or_nil_with_block.respond_to?(:call)
    @checks << object_or_nil_with_block
  else
    raise ArgumentError, "A check must respond to #call."
  end
  self
end

#add_error(key, message, options = {}) ⇒ Object

Public: Add an error message to the checker in order to have it rendered in the status request.

It is suggested that you use I18n and locale files for these messages, as is done with the pre-built checks. If you’re using I19n, you’ll need to define ‘activemodel.errors.models.rapporteur/checker.attributes.base.<your key>`.

Examples

checker.add_error("You failed.")
checker.add_error(:i18n_key_is_better)

Returns self.



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# File 'lib/rapporteur/checker.rb', line 102

def add_error(key, message, options={})
  options[:scope] = [:rapporteur, :errors, key]
  options[:default] = [message, message.to_s.humanize]
  errors.add(key, message, options)
  self
end

#add_message(name, message) ⇒ Object

Public: Adds a status message for inclusion in the success response.

name - A String containing the name or identifier for your message. This

is unique and may be overriden by other checks using the name
message name key.

message - A String or Numeric for the value of the message.

Examples

checker.add_message(:repository, '[email protected]/user/repo.git')
checker.add_message(:load, 0.934)

Returns self.



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# File 'lib/rapporteur/checker.rb', line 124

def add_message(name, message)
  @messages[name] = message
  self
end

#as_json(args = {}) ⇒ Object

Internal: Returns a hash of messages suitable for conversion into JSON.



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# File 'lib/rapporteur/checker.rb', line 132

def as_json(args={})
  @messages
end

#clear ⇒ Object

Public: Empties all configured checks from the checker. This may be useful for testing and for cases where you might’ve built up some basic checks but for one reason or another (environment constraint) need to start from scratch.

Returns self.



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# File 'lib/rapporteur/checker.rb', line 55

def clear
  @checks.clear
  self
end

#halt! ⇒ Object

Public: Checks can call this method to halt any further processing. This is useful for critical or fatal check failures.

For example, if load is too high on a machine you may not want to run any other checks.

Returns true.



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# File 'lib/rapporteur/checker.rb', line 69

def halt!
  @halted = true
end

#read_attribute_for_serialization(key) ⇒ Object Also known as: read_attribute_for_validation

Internal: Used by Rails’ JSON serialization, specifically in ActionController::Responder.



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# File 'lib/rapporteur/checker.rb', line 140

def read_attribute_for_serialization(key)
  @messages[key]
end

#run ⇒ Object

Public: This is the primary execution point for this class. Use run to exercise the configured checker and collect any application errors or data for rendering.

Returns self.



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# File 'lib/rapporteur/checker.rb', line 79

def run
  reset
  @checks.each do |object|
    object.call(self)
    break if @halted
  end
  self
end