25 Programming details for Ruby

This article mainly introduces Ruby's 25 programming details (tips, practical code snippet), this article directly gives the topic and the corresponding code, needs the friend may refer to under

1.try never throws an exception to return nil when not

The code is as follows:

province_id = Province.find_by_name (Prov). Try (: ID)

2.find (: A: Condotions) method does not speak but with

The code is as follows:

Mobile_info = Mobileinfo.find (: I,: Conditions => ["Mobile_num =?", Mobile_num.to_i])

3.find (: All,: SELECT,: Conditions)

The code is as follows:

Support_amount_a = Provincemerchantchangevalue.find (: All,: Select => "DISTINCT change_value_id",

: Conditions => [status = 1 and merchant_id =? and province_id =? and channel_id in (select ID from channels where status = 1) ",

MERCHANT_ID, province_id]). map {|cv| cv.change_value_id}.compact

support_amount_s = Changevalue.find (: All,:select => "price": Conditions => ["IDs in (?)", Support_amount_a])

. map {|cv| cv.try (:p rice). To_i}.compact

4. Send POST request can be executed in shell

The code is as follows:

Curl-d "channel= Citic different pay &action_type= Entertainment people's Day-mobile recharge &user_indicate=13911731997&original_amount=10000" http:// Xx.xxx.xxx:3000/search.json

5.Ruby Pure Data structure (STRUCT and openstruct)

Tell the difference between them:

Struct need to begin with a clear declaration of the field; And openstruct people like their name, you can add attributes at any time

Excellent Struct performance; And Openstruct almost, the specific performance gap can be seen here: http://stackoverflow.com/questions/1177594/ruby-struct-vs-openstruct

Struct is a Ruby interpreter built in, implemented in C; Openstruct is the Ruby Standard library, Ruby implements

Different APIs: Struct API and Openstruct

6. Mime::type.register

The code is as follows:

Mime::type.register "Application/json",: Ejson

Config/initializers/mime_types.rb

7.config/initializers/secure_problem_solved.rb

The code is as follows:

Activesupport::coreextensions::hash::conversions::xml_parsing.delete (' symbol ')

Activesupport::coreextensions::hash::conversions::xml_parsing.delete (' Yaml ')

8.config/initializers/new_rails_default.rb

The code is as follows:

If defined? (ActiveRecord)

# Include Active record class name as root for JSON serialized output.

Activerecord::base.include_root_in_json = True

# Store the full class name (including module namespace) in STI type column.

Activerecord::base.store_full_sti_class = True

End

Actioncontroller::routing.generate_best_match = False

# Use the ISO 8601 format for JSON serialized The Times and dates.

Activesupport.use_standard_json_time_format = True

# Don ' t escape HTML entities in JSON, leave this for the #json_escape helper.

# If you ' re including raw JSON into an HTML page.

Activesupport.escape_html_entities_in_json = False

9.MemCacheStore Cache

The code is as follows:

@_cache = Activesupport::cache::memcachestore.new (

config[' Host ', {: namespace => ' #{config[' namespace ']}::#{@name} '}

)

Localhost::callback_lock

@_cache.write (pay_channel.channel_id, ' true ')

v = @_cache.read (pay_channel.channel_id)

If V.nil? | | V!= ' true '

return False

Else

return True

End

End

10. Federated Index

The code is as follows:

Gem ' Composite_primary_keys ', ' 6.0.1 '

Https://github.com/momoplan

0.Hash Assert_valid_keys White List

11.puma-c puma_service_qa.rb

12.pow

Time

The code is as follows:

Start_time = Start_time.to_s.to_datetime.at_beginning_of_day

End_time = End_time.to_s.to_datetime.end_of_day

14.merchant.instance_of? Mplusmerchant

The code is as follows:

M_ORDER[:MERCHANT_ID] = (merchant.instance_of? mplusmerchant)? Merchant.id:merchant

15.will_paginate Rails

CONFIG/ENVIRONMENT.RB files need to be modified after installation

At the end of the file add:

The code is as follows:

Require ' will_paginate '

To modify the index method in the controller file:

# @products = Product.find (: All)

@products = Product.paginate:p Age => params[:p age],

:p Er_page => 2

. pagination

= Will_paginate @mplus_orders,: Class => ' digg_pagination '

Better have an include

# Excel Generator

The code is as follows:

Gem ' spreadsheet ', ' ~> 0.7.3 '

province =%w{Anhui Beijing Fujian Gansu Guangdong Guangxi Guizhou Hainan Hebei Henan Heilongjiang Hubei

Hunan Jilin Jiangsu Jiangxi Liaoning Inner Mongolia Ningxia Qinghai Shandong Shanxi Shaanxi Shanghai

Sichuan Tianjin Tibet Xinjiang Yunnan Zhejiang Chongqing

MONTH = 1.upto (in). to_a

Def self.total_to_xls (year = ' = ', opts = {})

Book = Spreadsheet::workbook.new

Sheet1 = Book.create_worksheet

months = MONTH

months = Opts[:month].to_s.split (/,/) if Opts[:month]

Fixed_row = months.collect{|m| m.to_s + ' month '}.insert (0, ')

Sheet1.row (0). Concat (Fixed_row)

Row1 = [']

(Months.size-1). Times {Row1 << [' Number of users ', ' Amount ', ' Order number ']}

Sheet1.row (1). Concat (row1.flatten!)

row = 2

Sheet1.row (Row). Insert (0, ' national ')

Months.each_with_index do |m, i|

Sheet1.row (Row). Insert (i*3 + 1, Self.monthly_users_count (m))

Sheet1.row (Row). Insert (I*3 + 2, Self.monthly_amount (m))

Sheet1.row (Row). Insert (I*3 + 3, Self.monthly_orders_count (m))

End

Province.each do |province|

row = 1

Sheet1.row (Row). Insert (0, province)

Months.each_with_index do |m, i|

Sheet1.row (Row). Insert (i*3 + 1, self.monthly_users_count_by_province (M, province))

Sheet1.row (Row). Insert (I*3 + 2, self.monthly_amount_by_province (M, province))

Sheet1.row (Row). Insert (I*3 + 3, self.monthly_orders_count_by_province (M, province))

End

End

Path = "Tmp/phone_recharge.xls"

Book.write Path

Path

End

Inject ({})

The code is as follows:

Selected_conditions = Base_conditions.inject ({}) do |hash, data|

Hash[data.first] = Data.last unless Data.last.blank?

Hash

End

18.time_str.instance_of?

The code is as follows:

Return TIME_STR if time_str.instance_of? Time

19.person.instance_eval

The code is as follows:

Person.instance_eval do

def species

"Homo Sapien"

End

End

20.class_eval

The code is as follows:

Class Foo

End

Metaclass = (class << Foo; self; end)

Metaclass.class_eval do

def species

"Homo Sapien"

End

End

End

21.Ruby in respond_to? And the use of send

Http://galeki.is-programmer.com/posts/183.html

Because obj objects cannot respond to talk this message, if you use respond_to? This method enables you to determine whether an object can respond to a given message.

The code is as follows:

obj = object.new

If obj.respond_to? ("Talk")

Obj.talk

Else

Puts "Sorry, object can ' t talk!"

End

Request = Gets.chomp

If book.respond_to? (Request)

Puts Book.send (request)

Else

Puts "Input error"

End

22.method_missing, a Ruby Programmer's dream Lover

The code is as follows:

Def method_missing (method, *args)

If method.to_s =~/(. *) _with_cent$/

Attr_name = $

If self.respond_to? (Attr_name)

'%.2f '% (Self.send (attr_name). to_f/100.00)

Else

Super

End

End

End

23.chomp

The Chomp method is to remove the trailing character of the string, such as N,r ... and gets the default separator is n

hash.each_pair{|k,v|} & Send ()

The code is as follows:

If bank_order.present?

Data_hash.each_pair {|k, v| bank_order.send ("#{k}=", V)}

Else

Bank_order = Bankorder.new Data_hash

End

25.config.middleware through Rake-t can be viewed in config/-removal of unnecessary middleware

26.1.day.ago.strftime ('%y%m%d ')