生成plugin骨架代碼:
Ruby代碼

1. ruby?script\generate?plugin?MyPlugin??

ruby script\generate plugin MyPlugin

功能需求:
在BlogController中把所有符合條件的Post(Model)生成為xml
如果不使用插件,很easy :
in BlogController
Ruby代碼

1. def?export_to_xml??
2. ??posts?=?Post.find(:all,?:order?=>?'published_date',??
3. ??????:conditions?=>?['title?=??',?'love'])??
4. ??send_data?posts.to_xml,?:type?=>?'text/xml;?charset=UTF-8;',??
5. ??????:disposition?=>?"attachment;?filename=posts.xml"??
6. end??

def export_to_xmlposts = Post.find(:all, :order => 'published_date',:conditions => ['title = ?', 'love'])send_data posts.to_xml, :type => 'text/xml; charset=UTF-8;',:disposition => "attachment; filename=posts.xml"
end

如果使用插件,我們要求能這樣:
Ruby代碼

1. class?BlogController?<?ApplicationController??
2. ??my_plugin?:post??
3. ????
4. ??def?to_xml??
5. ????export_to_xml??
6. ??end??
7. end??

class BlogController < ApplicationControllermy_plugin :postdef to_xmlexport_to_xmlend
end

OK,立刻滿足以上的要求,進入你的project:
生成plugin Ruby代碼

1. ruby?script\generate?plugin?MyPlugin??

ruby script\generate plugin MyPlugin

and than to find:
vendor/plugins/my_plugin/lib/my_plugin.rb
接著就是edit了:
Ruby代碼

1. module?MyPlugin??
2. ????
3. ??def?self.included(base)??
4. ????base.extend(ClassMethods)??
5. ??end??
6. ??
7. ??class?Config??
8. ????attr_reader?:model??
9. ????attr_reader?:model_id??
10. ??????
11. ????def?initialize(model_id)??
12. ??????@model_id?=?model_id??
13. ??????@model?=?model_id.to_s.camelize.constantize??
14. ????end??
15. ??????
16. ????def?model_name??
17. ??????@model_id.to_s??
18. ????end??
19. ??end??
20. ????
21. ??module?ClassMethods??
22. ??????
23. ????def?my_plugin(model_id?=?nil)??
24. ??????model_id?=?self.to_s.split('::').last.sub(/Controller$/,?'').pluralize.singularize.underscore?unless?model_id??
25. ??????@my_plugin_config?=?MyPlugin::Config.new(model_id)??
26. ??????include?MyPlugin::InstanceMethods??
27. ????end??
28. ??????
29. ????def?my_plugin_config??
30. ??????@my_plugin_config?||?self.superclass.instance_variable_get('@my_plugin_config')??
31. ????end??
32. ??????
33. ??end??
34. ??
35. ??module?InstanceMethods??
36. ??????
37. ????def?export_to_xml??
38. ??????data?=?self.class.my_plugin_config.model.find(:all,?:order?=>?'published_date',?:conditions?=>?conditions_for_collection)??
39. ??????send_data?data.to_xml,?:type?=>?'text/xml;?charset=UTF-8;',??
40. ????????:disposition?=>?"attachment;?filename=#{self.class.my_plugin_config.model_name.pluralize}.xml"??
41. ????end??
42. ??????
43. ????#?在controller中覆蓋此method,寫入滿足的條件??
44. ????def?conditions_for_collection??
45. ????end??
46. ??????
47. ??end??
48. ??
49. end??

module MyPlugindef self.included(base)base.extend(ClassMethods)endclass Configattr_reader :modelattr_reader :model_iddef initialize(model_id)@model_id = model_id@model = model_id.to_s.camelize.constantizeenddef model_name@model_id.to_sendendmodule ClassMethodsdef my_plugin(model_id = nil)model_id = self.to_s.split('::').last.sub(/Controller$/, '').pluralize.singularize.underscore unless model_id@my_plugin_config = MyPlugin::Config.new(model_id)include MyPlugin::InstanceMethodsenddef my_plugin_config@my_plugin_config || self.superclass.instance_variable_get('@my_plugin_config')endendmodule InstanceMethodsdef export_to_xmldata = self.class.my_plugin_config.model.find(:all, :order => 'published_date', :conditions => conditions_for_collection)send_data data.to_xml, :type => 'text/xml; charset=UTF-8;',:disposition => "attachment; filename=#{self.class.my_plugin_config.model_name.pluralize}.xml"end# 在controller中覆蓋此method,寫入滿足的條件def conditions_for_collectionendendend

OK了嗎? No No No 還要讓rails加載plugin,在rails應用啟動時,會到vendor/plugins目錄查找所有plugin,并執行其中的init.rb
那么就edit init.rb
Ruby代碼

1. ActionController::Base.class_eval?do??
2. ??include?MyPlugin??
3. end??

ActionController::Base.class_eval doinclude MyPlugin
end

或edit這樣:
Ruby代碼

1. require?'my_plugin'??
2. ActionController::Base.send?:include,?MyPlugin??

require 'my_plugin'
ActionController::Base.send :include, MyPlugin

最后就按上面的需求寫入controller了

轉載于:https://www.cnblogs.com/orez88/articles/1550476.html

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