Module: BarkestCore::StatusHelper

Included in:
ApplicationControllerBase
Defined in:
app/helpers/barkest_core/status_helper.rb

Overview

This module contains helper methods related to status reporting.

Instance Method Summary collapse

Instance Method Details

#clear_system_status ⇒ Object

Clears the system status log file.

If the file does not exist, it is created as a zero byte file. This is important for the status checking, since if there is no log file it will report an error.



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# File 'app/helpers/barkest_core/status_helper.rb', line 96

def clear_system_status
  unless BarkestCore::GlobalStatus.locked?
    # open, truncate, and close.
    File.open(BarkestCore::WorkPath.system_status_file,'w').close
  end
end

#show_system_status(options = {}) ⇒ Object

Shows the system status while optionally performing a long running code block.

Accepted options:

url_on_completion

This is the URL you want to redirect to when the long running code completes. If not set, then the completion button will have an empty HREF which means it will simply reload the status page. It is therefore highly recommended that you provide this value when using this method.

completion_button

This is the label for the button that becomes visible when the long running code completes. Defaults to ‘Continue’.

main_status

This is the initial status to report for the system when a long running code block is provided.

If a code block is provided, this will reset the system status and spawn a thread to run the code block. Before running the code block, it will acquire a GlobalStatus lock and set the initial status. When the code block exits, either through error or normal behavior, the GlobalStatus lock will be released.

It will yield the status object to the code block on a successful lock, or it will yield false to the code block to let it know that a lock could not be acquired. You should check for this in your code block and handle the error as appropriate.

Example 1:

def my_action
  Spawling.new do
    GlobalStatus.lock_for do |status|
      if status
        clear_system_status   # reset the log file.
        # Do something that takes a long time.
        ...
      end
    end
  end
  show_system_status(:url_on_completion => my_target_url)
end

Example 2:

def my_action
  show_system_status(:url_on_completion => my_target_url) do |status|
    if status
      # Do something that takes a long time.
      ...
    end
  end
end

The benefits of Example 2 is that it handles the thread spawning and status locking for you.



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# File 'app/helpers/barkest_core/status_helper.rb', line 60

def show_system_status(options = {})
  options = {
      url_on_completion: nil,
      completion_button: 'Continue',
      main_status: 'System is busy'
  }.merge(options || {})

  if block_given?
    clear_system_status
    Spawnling.new do
      status = BarkestCore::GlobalStatus.new
      if status.acquire_lock
        status.set_message options[:main_status]
        begin
          yield status
        ensure
          status.release_lock
        end
      else
        yield false
      end
    end
  end

  session[:status_comp_url] = options[:url_on_completion]
  session[:status_comp_lbl] = options[:completion_button]

  redirect_to status_current_url
end

#status_button_label ⇒ Object

Gets the label for the button to show when the long running process completes.



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# File 'app/helpers/barkest_core/status_helper.rb', line 113

def status_button_label
  session[:status_comp_lbl].to_s
end

#status_redirect_url ⇒ Object

Gets the URL to redirect to when the long running process completes.



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# File 'app/helpers/barkest_core/status_helper.rb', line 106

def status_redirect_url
  session[:status_comp_url].to_s
end