Ruby on Rails Development

Ruby on Rails Development:

use INCR to make variable increased by 1, it’s atomic command, thread safe.
LPUSH, RPUSH, LLEN, LPOP, RPOP, LRANGE, list commands
SADD, SREM, SISMEMBER, SMEMBERS, SUNION combine two sets
ZADD, Z is a Sorted Sets based on the associated score.
HSET, HGETALL, HGET, hash set in Redis, set value and get value.
For future reading: Redis Doc, Redis Commands, Redis Twitter Clone, Redis data type

Firebug in Firefox is a great tool!!!:
Problem and Tips:
如果想要找到element的绑定事件，请用firebug in firefox
Click the firebug icon, choose the “Enable all active panels” to activate the great functionality.
I can get the binding event for the element.

About the ruby performance optimization: 正在读这本书的Beta版本

Ruby Performance Optimization

两点注意：memory和GC，临时的变量，String::<< is very efficient. Each iterator will get a lot of objects created.

Ruby bad in two areas: large data processing and complex computations. Ruby的两个弱势的地方。

Databases are really good at complex computations and other kinds of data manipulation.
Rewrite the Ruby gem in C.

Q: 智力竞猜，irb有多少的实现？
A: One line: loop { p eval gets }

use PRY the great console instead of the irb:
gem install pry pry-doc gist

gist String#each___line, put the code on github.
help to see command list of pry.
show-method, show-doc
in pry, use . to use the shell command
nesting
jump-to 0
show-input
!
amend-line, change the method code.

Pry can do:

show method definition, ruby and C implementation.
show input of users.
gist the help doc to github
.cd change the locaiton through the shell command.
go into the gem and show contants, method, …
jump-to in the nesting gems
amend-line modify the mistake before.

edit-method method, open a new editor window to modify the code.
binding pry, for debug
whereami

install gem pry in the rails, modify config/environment/devlopment.rb file,

ls -i, show the variables,
Josh Mair, explain the pry
like step in debugging, remote debuggin, pry-exception___explorer open pry after the exception happened,