diff options
Diffstat (limited to 'railties/guides/source/active_support_core_extensions.textile')
| -rw-r--r-- | railties/guides/source/active_support_core_extensions.textile | 72 |
1 files changed, 35 insertions, 37 deletions
diff --git a/railties/guides/source/active_support_core_extensions.textile b/railties/guides/source/active_support_core_extensions.textile index dfc4d38112..7333a81cf9 100644 --- a/railties/guides/source/active_support_core_extensions.textile +++ b/railties/guides/source/active_support_core_extensions.textile @@ -167,6 +167,12 @@ def log_info(sql, name, ms) end </ruby> ++try+ can also be called without arguments but a block, which will only be executed if the object is not nil: + +<ruby> +@person.try { |p| "#{p.first_name} #{p.last_name}" } +</ruby> + NOTE: Defined in +active_support/core_ext/object/try.rb+. h4. +singleton_class+ @@ -395,39 +401,6 @@ C.new(0, 1).instance_values # => {"x" => 0, "y" => 1} NOTE: Defined in +active_support/core_ext/object/instance_variables.rb+. -h5. +copy_instance_variables_from(object, exclude = [])+ - -Copies the instance variables of +object+ into +self+. - -Instance variable names in the +exclude+ array are ignored. If +object+ -responds to +protected_instance_variables+ the ones returned are -also ignored. For example, Rails controllers implement that method. - -In both arrays strings and symbols are understood, and they have to include -the at sign. - -<ruby> -class C - def initialize(x, y, z) - @x, @y, @z = x, y, z - end - - def protected_instance_variables - %w(@z) - end -end - -a = C.new(0, 1, 2) -b = C.new(3, 4, 5) - -a.copy_instance_variables_from(b, [:@y]) -# a is now: @x = 3, @y = 1, @z = 2 -</ruby> - -In the example +object+ and +self+ are of the same type, but they don't need to. - -NOTE: Defined in +active_support/core_ext/object/instance_variables.rb+. - h4. Silencing Warnings, Streams, and Exceptions The methods +silence_warnings+ and +enable_warnings+ change the value of +$VERBOSE+ accordingly for the duration of their block, and reset it afterwards: @@ -1216,6 +1189,12 @@ To insert something verbatim use the +raw+ helper rather than calling +html_safe <%= raw @cms.current_template %> <%# inserts @cms.current_template as is %> </erb> +or, equivalently, use <tt><%==</tt>: + +<erb> +<%== @cms.current_template %> <%# inserts @cms.current_template as is %> +</erb> + The +raw+ helper calls +html_safe+ for you: <ruby> @@ -2859,9 +2838,9 @@ d.end_of_week # => Sun, 09 May 2010 +beginning_of_week+ is aliased to +monday+ and +at_beginning_of_week+. +end_of_week+ is aliased to +sunday+ and +at_end_of_week+. -h6. +next_week+ +h6. +prev_week+, +next_week+ -+next_week+ receives a symbol with a day name in English (in lowercase, default is +:monday+) and it returns the date corresponding to that day in the next week: +The method +next_week+ receives a symbol with a day name in English (in lowercase, default is +:monday+) and it returns the date corresponding to that day: <ruby> d = Date.new(2010, 5, 9) # => Sun, 09 May 2010 @@ -2869,6 +2848,14 @@ d.next_week # => Mon, 10 May 2010 d.next_week(:saturday) # => Sat, 15 May 2010 </ruby> +The method +prev_week+ is analogous: + +<ruby> +d.prev_week # => Mon, 26 Apr 2010 +d.prev_week(:saturday) # => Sat, 01 May 2010 +d.prev_week(:friday) # => Fri, 30 Apr 2010 +</ruby> + h6. +beginning_of_month+, +end_of_month+ The methods +beginning_of_month+ and +end_of_month+ return the dates for the beginning and end of the month: @@ -2946,6 +2933,15 @@ Date.new(2010, 4, 30).months_ago(2) # => Sun, 28 Feb 2010 Date.new(2009, 12, 31).months_since(2) # => Sun, 28 Feb 2010 </ruby> +h6. +weeks_ago+ + +The method +weeks_ago+ works analogously for weeks: + +<ruby> +Date.new(2010, 5, 24).weeks_ago(1) # => Mon, 17 May 2010 +Date.new(2010, 5, 24).weeks_ago(2) # => Mon, 10 May 2010 +</ruby> + h6. +advance+ The most generic way to jump to other days is +advance+. This method receives a hash with keys +:years+, +:months+, +:weeks+, +:days+, and returns a date advanced as much as the present keys indicate: @@ -3067,6 +3063,8 @@ yesterday tomorrow beginning_of_week (monday, at_beginning_of_week) end_on_week (at_end_of_week) +weeks_ago +prev_week next_week months_ago months_since @@ -3239,6 +3237,8 @@ beginning_of_day (midnight, at_midnight, at_beginning_of_day) end_of_day beginning_of_week (monday, at_beginning_of_week) end_on_week (at_end_of_week) +weeks_ago +prev_week next_week months_ago months_since @@ -3407,7 +3407,5 @@ NOTE: Defined in +active_support/core_ext/load_error.rb+. h3. Changelog -"Lighthouse ticket":https://rails.lighthouseapp.com/projects/16213/tickets/67 - * August 10, 2010: Starts to take shape, added to the index. * April 18, 2009: Initial version by "Xavier Noria":credits.html#fxn |