Thinking in Patterns chapter 3: Simplifying Idioms

Thinking in Patterns with Java V0.9: chapter 3: Simplifying Idioms: TIPatterns.htm#_Toc41169691

1, Sections name of today's learning;

    Messenger. 22

    Collecting Parameter. 24

2, What is it talk about in these sections and my comments and feeling for the content:

  Bruce's book always give me good reading experiment.

  He puts the Messenger and Collecting parameter at Simplifying Idioms

chapter, I think the reason is that these two patterns can be used in the basis implementation of a process which performing a specific task.

  1), Messenger.

  If we need translate many related parameters into a method, we can package

these parameters into an object, then we can translate this object into that method instead.

  I think I can use this Messenger pattern in our LearnDiary Open Source

Project like this: Because we use Struts framework, it need tranlate some

attributes from a Struts Action into a Jsp page, my method before is set these

attributes into request scope seperately, then get these attributes in Jsp

page seperately; Now, if some of these attributes is related, we can package some of these attributes into an attribute object, then translate this packaged attribute object into Jsp page. But, I think this need balance, we can't package all the attributes into only an attribute object without any proper reason.

  2), Collecting Parameter.

  Frankly speaking, I have never used Collecting Parameter patterns before, I

haven't ever thought that a parameter can be used like this: pass a parameter

into a method, let this method do some change on this parameter, then pass

this changed parameter into another method, and let this another method do

some change on this changed parameter again, and so on. That's really an

intresting use of a parameter. Just like flow line production:). But,

remember, the parameter is always only one same object, only the content of

this object changed. 

  Let me think a while, how can I use this pattern into our LearnDiary

project? aha, a little example coming, in our project, there is an Email

object, it consists of email address and title, content, and so on. Email

address can be gotten from user object, and email's title and content can be

gotten from an article object. So, create method at user and article object

for adding some field into email object. Then, translate email object into

user and article object's corresponding method to do some change in turn.  

 

3, My questions about the english language;

  1), Strange words:

  trivial, pass around, magnitude, dummy, pollen, accumulating