25 Programming details for Ruby (tips, Practical code Snippets) _ruby topics

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

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

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

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

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

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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 => ["ID in (?)", support_amount_a]) \
. map {|cv| cv.try (:p rice). To_i}.compact

4. Send POST request can be executed in shell

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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

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Mime::type.register "Application/json",: Ejson
Config/initializers/mime_types.rb

7.config/initializers/secure_problem_solved.rb

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

8.config/initializers/new_rails_default.rb

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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

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@_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

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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

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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

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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:

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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

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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 ({})

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Selected_conditions = Base_conditions.inject ({}) do |hash, data|
Hash[data.first] = Data.last unless Data.last.blank?
Hash
End

18.time_str.instance_of?

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Return TIME_STR if time_str.instance_of? Time

19.person.instance_eval

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Person.instance_eval do
def species
"Homo Sapien"
End
End

20.class_eval

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Class Foo
End
Metaclass = (class << Foo; self; end)
Metaclass.class_eval do
def species
"Homo Sapien"
End
End
End

use of respond_to and send in 21.Ruby
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.

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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

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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 the gets default separator is \ n

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

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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 ')