问题描述
我有一个方法可以调用一个对象，但我似乎无法提取这个对象的属性，我不明白为什么。
def set_cashier
test = User.first
result = test.login
Rails.logger.debug "User is: #{result}"
因为我在 rubymine IDE 的第二行设置了一个断点（我可以看到以下内容）
def set_cashier
test = User.first test: #<User:0x00000004809ea0>
result = test.login result: nil test: #<User:0x00000004809ea0>
Rails.logger.debug "User is: #{result}"
我知道我有这个对象的属性，比如 id 和 login。当我在我的 IDE 中运行调试器时，我可以看到 @attributes = Hash(17 elements) 并且我可以看到它们被列为 'id' = "433" 和 'login' = "firstname.lastname" 等......在 rubymine 调试器中它看起来有点像这样。 ..
result = nil
test = {User}#<User:0x00000004809ea0>
@attributes = Hash(17 elements)
'id' = "433"
'login' = "firstname.lastname"
...
如何返回“登录”的值？
test = User.first 似乎给出了一个我可以在调试器变量选项卡中看到的对象，我可以打开它并查看“@attributes = Hash(17 个元素)”的值，我可以在其中看到这些值。 ……然而……
"result = test.login" 给出了一个令人困惑的 nil 结果
我认为“test = User.first.login”应该可以工作......
def set_cashier
test = User.first.login
result = test
Rails.logger.debug "User.first is: #{result}"
但这给出了同样的错误......太令人困惑了。
You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.map
我已经在这几天了。如果这个问题没有意义，请告诉我。
感谢您抽出宝贵时间。
更新：
根据评论者的要求，我将包含用户模型的代码 （顺便说一下……我继承了这段代码……所以这个文件中没有任何内容是我写的）
注意： Rails 3.1（从 rails 2.x 应用程序更新） 红宝石 1.9.3p551
用户.rb
class User < ActiveRecord::Base
acts_as_userstamp
has_and_belongs_to_many "roles"
# Virtual attribute for the unencrypted password
attr_accessor :password
validates_presence_of :login,:email
validates_presence_of :password,:if => :password_required?
validates_presence_of :password_confirmation,:if => :password_required?
validates_length_of :password,:within => 4..40,:if => :password_required?,:allow_nil => true
validates_confirmation_of :password,:if => :password_required?
validates_length_of :login,:within => 3..40,:allow_nil => true
validates_length_of :email,:within => 3..100,:allow_nil => true
validates_uniqueness_of :login,:email,:case_sensitive => false
validates_uniqueness_of :cashier_code,:if => :cashier_code
validates_format_of :login,:with => /[^0-9]/,:message => "must contain a non-numeric character"
before_save :encrypt_password
before_save :add_cashier_code
before_save :disable_reason_cannot_login_on_reenable
def disable_reason_cannot_login_on_reenable
return unless self.can_login && self.can_login_changed?
self.reason_cannot_login = "" if self.reason_cannot_login && self.reason_cannot_login.length > 0
end
belongs_to :contact
has_one :skedjulnator_access
####################################################
# I HAVE NO IDEA WHAT THIS IS HERE FOR,BUT IF YOU #
# FORGET ABOUT IT YOU WILL SPEND AN HOUR TRYING TO #
# figURE OUT WHAT YOU DID WRONG #
####################################################
# prevents a user from submitting a crafted form that bypasses activation
# anything else you want your user to change should be added here.
attr_accessible :login,:password,:password_confirmation,:can_login,:shared
scope :can_login,{:conditions => ["can_login = 't'"]}
def self.hidden_columns
super + [:crypted_password,:salt]
end
def can_view_disciplinary_information?
!! (self.contact and self.contact.worker and self.contact.worker.worker_type_today and self.contact.worker.worker_type_today.name != 'inactive')
end
def update_skedjulnator_access_time
self.skedjulnator_access ||= SkedjulnatorAccess.new
self.skedjulnator_access.user_id_will_change!
self.skedjulnator_access.save!
end
def grantable_roles
self.roles.include?(Role.find_by_name('ADMIN')) ? Role.find(:all) : self.roles
end
def to_s
login
end
def self.reset_all_cashier_codes
self.find(:all).each{|x|
x.reset_cashier_code
x.save
}
end
def contact_display_name
self.contact ? self.contact.display_name : self.login
end
def add_cashier_code
reset_cashier_code if !self.shared and cashier_code.nil?
end
def reset_cashier_code
valid_codes = (1000..9999).to_a - User.find(:all).collect{|x| x.cashier_code}
my_code = valid_codes[rand(valid_codes.length)]
self.cashier_code = my_code
end
def merge_in(other)
for i in [:actions,:donations,:sales,:types,:users,:volunteer_tasks,:contacts,:gizmo_returns]
User.connection.execute("UPDATE #{i.to_s} SET created_by = #{self.id} WHERE created_by = #{other.id}")
User.connection.execute("UPDATE #{i.to_s} SET updated_by = #{self.id} WHERE updated_by = #{other.id}")
end
["donations","sales","volunteer_tasks","disbursements","recyclings","contacts"].each{|x|
User.connection.execute("UPDATE #{x.to_s} SET cashier_created_by = #{self.id} WHERE cashier_created_by = #{other.id}")
User.connection.execute("UPDATE #{x.to_s} SET cashier_updated_by = #{self.id} WHERE cashier_updated_by = #{other.id}")
}
self.roles = (self.roles + other.roles).uniq
self.save!
end
# Authenticates a user by their login name and unencrypted password. Returns the user or nil.
def self.authenticate(login,password)
if login.to_i.to_s == login
u = find_by_contact_id(login.to_i)
else
u = find_by_login(login) # need to get the salt
end
return u if u && u.can_login && u.authenticated?(password)
return nil
end
# Encrypts some data with the salt.
def self.encrypt(password,salt)
Digest::SHA1.hexdigest("--#{salt}--#{password}--")
end
# Encrypts the password with the user salt
def encrypt(password)
self.class.encrypt(password,salt)
end
def authenticated?(password)
crypted_password == encrypt(password)
end
def remember_token?
remember_token_expires_at && Time.Now.utc < remember_token_expires_at
end
# These create and unset the fields required for remembering users between browser closes
def remember_me
remember_me_for 2.weeks
end
def remember_me_for(time)
remember_me_until time.from_Now.utc
end
def remember_me_until(time)
self.remember_token_expires_at = time
self.remember_token = encrypt("#{email}--#{remember_token_expires_at}")
save(false)
end
def forget_me
self.remember_token_expires_at = nil
self.remember_token = nil
save(false)
end
# start auth junk
def User.current_user
Thread.current['user'] || User.fake_new
end
attr_accessor :fake_logged_in
def User.fake_new
u = User.new
u.fake_logged_in = true
u
end
def logged_in
! fake_logged_in
end
def to_privileges
return "logged_in" if self.logged_in
end
def privileges
@privileges ||= _privileges
end
def _privileges
olda = []
return olda if !self.can_login
a = [self,self.contact,self.contact ? self.contact.worker : nil,self.roles].flatten.select{|x| !x.nil?}.map{|x| x.to_privileges}.flatten.select{|x| !x.nil?}.map{|x| Privilege.by_name(x)}
while olda != a
a = a.select{|x| !x.restrict} if self.shared
olda = a.dup
a << olda.map{|x| x.children}.flatten
a = a.flatten.sort_by(&:name).uniq
a = a.select{|x| !x.restrict} if self.shared
end
a = a.map{|x| x.name}
a
end
def has_privileges(*privs)
positive_privs = []
negative_privs = []
privs.flatten!
for i in privs
if i.match(/^!/)
negative_privs << i.sub(/^!/,"")
else
positive_privs << i
end
end
if positive_privs.length > 0
positive_privs << "role_admin"
end
if negative_privs.length > 0
negative_privs << "role_admin"
end
my_privs = self.privileges
#puts "NEG: #{negative_privs.inspect},POS: #{positive_privs.inspect},MY: #{my_privs.inspect}"
return (negative_privs & my_privs).length == 0 && ((positive_privs & my_privs).length > 0 || positive_privs.length == 0)
end
# end auth junk
protected
# before filter
def encrypt_password
return if password.blank?
self.salt = Digest::SHA1.hexdigest("--#{Time.Now.to_s}--#{login}--") if new_record?
self.crypted_password = encrypt(password)
end
def password_required?
crypted_password.blank? || !password.blank?
end
end
消除 IDE 作为问题的根源：
所以我运行 Rails 控制台并得到以下错误...
irb(main):001:0> User.first
User Load (0.5ms) SELECT "users".* FROM "users" LIMIT 1
(0.1ms) SHOW search_path
User Indexes (1.1ms) SELECT distinct i.relname,d.indisunique,d.indkey,t.oid
FROM pg_class t
INNER JOIN pg_index d ON t.oid = d.indrelid
INNER JOIN pg_class i ON d.indexrelid = i.oid
WHERE i.relkind = 'i'
AND d.indisprimary = 'f'
AND t.relname = 'users'
AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname IN ('"$user"','public') )
ORDER BY i.relname
User Indexes (0.4ms) SELECT c2.relname,i.indisunique,pg_catalog.pg_get_indexdef(i.indexrelid,true)
FROM pg_catalog.pg_class c,pg_catalog.pg_class c2,pg_catalog.pg_index i
WHERE c.relname = 'users'
AND c.oid = i.indrelid AND i.indexrelid = c2.oid
AND i.indisprimary = 'f'
AND i.indexprs IS NOT NULL
ORDER BY 1
(Object doesn't support #inspect)
=>
irb(main):002:0>
...非常混乱
解决方法
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