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Module: ActionView::Helpers::DebugHelper

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Included In:
::ActionDispatch::DebugView, ::ActionView::Base, ::ActionView::Helpers, ::ActionView::TestCase, ::ActionView::TestCase::Behavior
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
self, TagHelper, OutputSafetyHelper, CaptureHelper
Defined in: actionview/lib/action_view/helpers/debug_helper.rb

Overview

Action View Debug Helpers

Provides a set of methods for making it easier to debug Rails objects.

Constant Summary

TagHelper - Included

ARIA_PREFIXES, BOOLEAN_ATTRIBUTES, DATA_PREFIXES, PRE_CONTENT_STRINGS, TAG_TYPES

Instance Method Summary

  • #debug(object)

    Returns a YAML representation of object wrapped with <pre> and </pre>.

TagHelper - Included

#cdata_section

Returns a CDATA section with the given content.
#class_names

Alias for TagHelper#token_list.
#content_tag

Returns an HTML block tag of type name surrounding the content.
#escape_once

Returns an escaped version of html without affecting existing escaped entities.
#tag

Returns an HTML tag.
#token_list

Returns a string of tokens built from args.
#build_tag_values, #ensure_valid_html5_tag_name, #tag_builder

OutputSafetyHelper - Included

#raw

This method outputs without escaping a string.
#safe_join

This method returns an HTML safe string similar to what Array#join would return.
#to_sentence

Converts the array to a comma-separated sentence where the last element is joined by the connector word.

CaptureHelper - Included

#capture

The capture method extracts part of a template as a string object.
#content_for

Calling content_for stores a block of markup in an identifier for later use.
#content_for?

content_for? checks whether any content has been captured yet using content_for.
#provide

The same as content_for but when used with streaming flushes straight back to the layout.
#with_output_buffer

Use an alternate output buffer for the duration of the block.

Instance Method Details

#debug(object)

Returns a YAML representation of object wrapped with <pre> and </pre>. If the object cannot be converted to YAML using to_yaml, inspect will be called instead. Useful for inspecting an object at the time of rendering.

@user = User.new({ username: 'testing', password: 'xyz', age: 42})
debug(@user)
# =>
<pre class='debug_dump'>--- !ruby/object:User
attributes:
  updated_at:
  username: testing
  age: 42
  password: xyz
  created_at:
</pre>
[ GitHub ] 

  


# File 'actionview/lib/action_view/helpers/debug_helper.rb', line 28



def debug(object)
  Marshal.dump(object)
  object = ERB::Util.html_escape(object.to_yaml)
  content_tag(:pre, object, class: "debug_dump")
rescue # errors from Marshal or YAML
  # Object couldn't be dumped, perhaps because of singleton methods -- this is the fallback
  content_tag(:code, object.inspect, class: "debug_dump")
end