Module: Sequel::Postgres::Comment

Defined in:

lib/sequel/extensions/pg_comment.rb

Overview

PostgreSQL-specific extension to set and retrieve comments on all database objects.

Constant Summary

STANDALONE_TYPES =

The types of PostgreSQL object that are commented on in their own right.

[
	:aggregate,
	:cast,
	:collation,
	:conversion,
	:database,
	:domain,
	:extension,
	:event_trigger,
	:foreign_data_wrapper,
	:foreign_table,
	:function,
	:index,
	:large_object,
	:materialized_view,
	:operator,
	:operator_class,
	:operator_family,
	:language,
	:procedural_language,
	:role,
	:schema,
	:sequence,
	:server,
	:table,
	:tablespace,
	:text_search_configuration,
	:text_search_dictionary,
	:text_search_parser,
	:text_search_template,
	:type,
	:view
]

CONTAINED_TYPES =

[
	:column,
	:constraint,
	:rule,
	:trigger
]

Class Method Summary

• .normalise_comment(comment) ⇒ String

  Strip indenting whitespace from a comment string.

Class Method Details

.normalise_comment(comment) ⇒ String

Strip indenting whitespace from a comment string.

Two rules are applied by this method:

1. Empty lines (that is, lines which have no characters in them, not even whitespace) are removed from the beginning and end of the string.

2. Whatever whitespace characters may be present before the first line of text will be removed from the beginning of each subsequent line of the comment, if it exists.

This means you can use heredocs and multi-line strings without having to play your own silly-buggers in order to not make the comments look like arse. If you like heredocs, you're encouraged to use this style:

comment_for :table, :foo, <<-EOF This is my comment.

 And here's another line.

EOF

On the other hand, if percent-quotes are more your cup of tea, you can go at them like this:

comment_for :table, :foo, %( This is my comment.

 And here's another line.

)

Be sure to not start the first line of your comment on the same line as the quote character, though, because that will mean the first line of the comment doesn't have any leading whitespace, and so whitespace won't be trimmed from the rest of the comment. So, don't do this:

comment_for :table, :foo, %(This won't work at all well. Since the first line of text doesn't have leading whitespace, these lines won't have it stripped either, and everything will look weird. )

# File 'lib/sequel/extensions/pg_comment.rb', line 96

def self.normalise_comment(comment)
	comment.tap do |s|
		s.gsub!(/\A\n+/, '')
		s.gsub!(/\n+\Z/, '')

		(s =~ /\A(\s+)/ and lede = $1) or lede = ''
		s.gsub!(/^#{lede}/, '')
	end
end