Ruby on Rails:验证CSV文件 [英] Ruby on Rails: Validate CSV file
问题描述
在导入CSV时遵循了RailsCast( http://railscasts.com/Episodes/396-importing-csv-and-excel ),我正在尝试验证要上传的文件是CSV文件.
Having followed the RailsCast on importing CSV (http://railscasts.com/episodes/396-importing-csv-and-excel), I am trying to validate that the file being uploaded is a CSV file.
我使用了宝石csv_validator
来做到这一点,如此处 https://github.com/mattfordham所述/csv_validator
I have used the gem csv_validator
to do so, as documented here https://github.com/mattfordham/csv_validator
所以我的模型如下:
class Contact < ActiveRecord::Base
belongs_to :user
attr_accessor :my_csv_file
validates :my_csv_file, :csv => true
def self.to_csv(options = {})
CSV.generate(options) do |csv|
csv << column_names
all.each do |contact|
csv << contact.attributes.values_at(*column_names)
end
end
end
def self.import(file, user)
allowed_attributes = ["firstname","surname","email","user_id","created_at","updated_at", "title"]
CSV.foreach(file.path, headers: true) do |row|
contact = find_by_email_and_user_id(row["email"], user) || new
contact.user_id = user
contact.attributes = row.to_hash.select { |k,v| allowed_attributes.include? k }
contact.save!
end
end
end
但是我的系统仍然允许我选择导入非CSV文件(例如.xls),并且收到结果错误:invalid byte sequence in UTF-8
.
But my system still allows me to select to import non-CSV files (such as .xls), and I receive the resulting error: invalid byte sequence in UTF-8
.
有人可以告诉我为什么以及如何解决吗?
Can someone please tell me why and how to resolve this?
请注意,我正在使用Rails 4.2.6
Please note that I am using Rails 4.2.6
推荐答案
您可以创建一个新类,例如ContactCsvRowValidator
:
You can create a new class, let's say ContactCsvRowValidator
:
class ContactCsvRowValidator
def initialize(row)
@row = row.with_indifferent_access # allows you to use either row[:a] and row['a']
@errors = []
end
def validate_fields
if @row['firstname'].blank?
@errors << 'Firstname cannot be empty'
end
# etc.
end
def errors
@errors.join('. ')
end
end
然后像这样使用它:
# contact.rb
def self.import(file, user)
allowed_attributes = ["firstname","surname","email","user_id","created_at","updated_at", "title"]
if file.path.split('.').last.to_s.downcase != 'csv'
some_method_which_handle_the_fact_the_file_is_not_csv!
end
CSV.foreach(file.path, headers: true) do |row|
row_validator = ContactCsvRowValidator.new(row)
errors = row_validator.errors
if errors.present?
some_method_to_handle_invaid_row!(row)
return
end
# other logic
end
end
可以轻松修改此模式以适合您的需求.例如,如果需要在多个不同的模型上进行导入,则可以创建一个基本的CsvRowValidator,以提供诸如validate_fields
,initialize
和errors
之类的基本方法.然后,您可以为所需的每个模型创建一个从CsvRowValidator继承的类,并实现自己的验证.
This pattern can easily be modified to fit your needs. For example, if you need to have import on several different models, you could create a base CsvRowValidator to provide basic methods such as validate_fields
, initialize
and errors
. Then, you could create a class inheriting from this CsvRowValidator for each model you want, having its own validations implemented.
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