Module: FlashTruncation

Included in:
ApplicationController
Defined in:
app/controllers/concerns/flash_truncation.rb

Overview

Module FlashTruncation provides the truncate_flash method to automatically trim long flash messages to prevent them from overflowing the cookie

Author:

  • Genome Research Ltd.

Constant Summary collapse

STRING_OVERHEAD =

Encoding a json string results in a two-byte overhead for the " either side. Taking this into account is strictly unnecessary, as we've already got a bit of overhead built in, but lets keep things as predictable as possible.

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Instance Method Summary collapse

Instance Method Details

#max_flash_size ⇒ Object

The maximum cookie size is 4096 bytes, however this is post-encryption, which increases the size. The value of 2048 was obtained by mapping the size of encrypted strings. In practice 2255 bytes was the largest size, but I rounded down to 2kb to provide a bit of overhead for array serialization, additional flash information to and allow for slight implementation changes.



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# File 'app/controllers/concerns/flash_truncation.rb', line 41

has_metadata do
  # NOTE: The following attribute is not required for Microarray Genotyping.
  # I think this might be broken and suggests that there should be separate classes for project: one for
  # next-gen sequencing that includes this attribute in it's metadata, and one for microarray genotyping
  # that doesn't.
  include ProjectManager::Associations
  include BudgetDivision::Associations

  custom_attribute(:project_cost_code, required: true)
  custom_attribute(:funding_comments)
  custom_attribute(:collaborators)
  custom_attribute(:external_funding_source)
  custom_attribute(:sequencing_budget_cost_centre)
  custom_attribute(:project_funding_model, in: PROJECT_FUNDING_MODELS)
  custom_attribute(:gt_committee_tracking_id)

  before_validation do |record|
    record.project_cost_code = nil if record.project_cost_code.blank?
    record.project_funding_model = nil if record.project_funding_model.blank?
  end
end

#truncate_flash(message, max_size = max_flash_size) ⇒ Array, String

Truncates the flash message to avoid an ActionDispatch::Cookies::CookieOverflow. Maximum cookie size is checked against ActionDispatch::Cookies::MAX_COOKIE_SIZE which is 4096 bytes; however:

  • This is the size of the session cookie post encryption, which inflates the size
  • This cookie also needs to contain other data, such as the session_id, user_uuid and user_name

Parameters:

  • message (Array, String) —

    The flash to truncate

  • max_size (Integer) (defaults to: max_flash_size) —

    The maximum allowed flash size

Returns:

  • (Array, String) —

    The truncated message



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# File 'app/controllers/concerns/flash_truncation.rb', line 26

has_metadata do
  # NOTE: The following attribute is not required for Microarray Genotyping.
  # I think this might be broken and suggests that there should be separate classes for project: one for
  # next-gen sequencing that includes this attribute in it's metadata, and one for microarray genotyping
  # that doesn't.
  include ProjectManager::Associations
  include BudgetDivision::Associations

  custom_attribute(:project_cost_code, required: true)
  custom_attribute(:funding_comments)
  custom_attribute(:collaborators)
  custom_attribute(:external_funding_source)
  custom_attribute(:sequencing_budget_cost_centre)
  custom_attribute(:project_funding_model, in: PROJECT_FUNDING_MODELS)
  custom_attribute(:gt_committee_tracking_id)

  before_validation do |record|
    record.project_cost_code = nil if record.project_cost_code.blank?
    record.project_funding_model = nil if record.project_funding_model.blank?
  end
end

#truncate_flash_array(array, max_size = max_flash_size) ⇒ Array

Handles truncation of arrays passed to the flash. This is not intended to be used directly, instead use truncate_flash.

Parameters:

  • array (Array) —

    The flash to truncate

  • max_size (Integer) (defaults to: max_flash_size) —

    The maximum allowed flash size

Returns:

  • (Array) —

    The truncated array

See Also:



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# File 'app/controllers/concerns/flash_truncation.rb', line 54

has_metadata do
  # NOTE: The following attribute is not required for Microarray Genotyping.
  # I think this might be broken and suggests that there should be separate classes for project: one for
  # next-gen sequencing that includes this attribute in it's metadata, and one for microarray genotyping
  # that doesn't.
  include ProjectManager::Associations
  include BudgetDivision::Associations

  custom_attribute(:project_cost_code, required: true)
  custom_attribute(:funding_comments)
  custom_attribute(:collaborators)
  custom_attribute(:external_funding_source)
  custom_attribute(:sequencing_budget_cost_centre)
  custom_attribute(:project_funding_model, in: PROJECT_FUNDING_MODELS)
  custom_attribute(:gt_committee_tracking_id)

  before_validation do |record|
    record.project_cost_code = nil if record.project_cost_code.blank?
    record.project_funding_model = nil if record.project_funding_model.blank?
  end
end