Class: RailsSpreadsheetReader::Base

Inherits:
Object
  • Object
show all
Includes:
ActiveModel::Model, ActiveModel::Validations::Callbacks
Defined in:
lib/rails_spreadsheet_reader/base.rb

Defined Under Namespace

Classes: InvalidTypeError, MethodNotImplementedError

Constant Summary collapse

BASE_ATTRIBUTES = 
%w(row_number record_with_error copied_errors collection)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(arr_or_hash = {}) ⇒ Base

Generalizes the constructor of ActiveModel::Model to make it work with an array argument. When an array argument is passed, it calls formatted_hash method to generate a Hash and then pass it to the ActiveModel::Model constructor

Parameters:

arr_or_hash

Array or Hash of values which represents an excel column.



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# File 'lib/rails_spreadsheet_reader/base.rb', line 135

def initialize(arr_or_hash = {})
  self.copied_errors = ActiveModel::Errors.new(self)
  if arr_or_hash.is_a?(Array)
    super(self.class.formatted_hash(arr_or_hash))
  else
    super(arr_or_hash)
  end
end

Instance Attribute Details

#collection ⇒ Object

Returns the value of attribute collection.



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# File 'lib/rails_spreadsheet_reader/base.rb', line 18

def collection
  @collection
end

#copied_errors ⇒ Object

Returns the value of attribute copied_errors.



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# File 'lib/rails_spreadsheet_reader/base.rb', line 17

def copied_errors
  @copied_errors
end

#record_with_error ⇒ Object

Returns the value of attribute record_with_error.



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# File 'lib/rails_spreadsheet_reader/base.rb', line 16

def record_with_error
  @record_with_error
end

#row_number ⇒ Object

Returns the value of attribute row_number.



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# File 'lib/rails_spreadsheet_reader/base.rb', line 15

def row_number
  @row_number
end

Class Method Details

.array_to_hash(arr) ⇒ Object

Transform an array [a0, a1, a2, …] to a Hash { a0 => 0, a1 => 1, etc } which is the format required by the #formatted_hash method.



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# File 'lib/rails_spreadsheet_reader/base.rb', line 209

def self.array_to_hash(arr)
  Hash[[*arr.map { |e| e.to_sym }.map.with_index]]
end

.formatted_hash(array) ⇒ Object

Returns the Hash representation of a given array using self.format method (which internally uses self.columns). The keys of this Hash are defined in the self.columns method and the values of each key depends on the order of the columns.

For example, given the following self.columns definition

def self.headers
  [:username, :email, :gender]
end

Or

def self.headers
  { :username => 0, :email => 1, :gender => 2 }
end

Row.formatted([username [email protected] male]) will return { username: ‘username’, email: ‘[email protected]’, gender: ‘male’ }

Parameters:

array

Array of values which represents an excel column.

Returns:

Hash representation of the given array which maps columns names to the array values.



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# File 'lib/rails_spreadsheet_reader/base.rb', line 115

def self.formatted_hash(array)

  if format.keys.count > 0
    parsed_row = {}
    format.each_pair { |key, col| parsed_row[key] = array[col] }
    return parsed_row
  end

  return nil
end

.headers ⇒ Object

Defines the columns of the excel that the class will read. This method must return a Array of strings/symbols (representing columns names) or a Hash (which map column names to columns indexes).

Array Example

def self.headers
  [:username, :email, :gender]
end

Hash Example

def self.headers
  { :username => 0, :email => 1, :gender => 2 }
end

Returns:

An Array or a Hash defining the columns of the excel.



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# File 'lib/rails_spreadsheet_reader/base.rb', line 85

def self.headers
  fail(
      MethodNotImplementedError,
      'Please implement this method in your class.'
  )
end

.last_record ⇒ Object 



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# File 'lib/rails_spreadsheet_reader/base.rb', line 32

def self.last_record
  @last_record ||= nil
end

.last_record=(record) ⇒ Object 



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# File 'lib/rails_spreadsheet_reader/base.rb', line 36

def self.last_record=(record)
  @last_record = record
end

.open(spreadsheet_file) ⇒ Object 



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# File 'lib/rails_spreadsheet_reader/base.rb', line 171

def self.open(spreadsheet_file)
  Roo::Spreadsheet.open(spreadsheet_file)
end

.persist(collection) ⇒ Object

Persist all rows of collection if they all are valid

Parameters:

row_collection

SpreadsheetReader::RowCollection instance



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# File 'lib/rails_spreadsheet_reader/base.rb', line 149

def self.persist(collection)
  if collection.valid?
    ActiveRecord::Base.transaction do
      collection.each do |row|
        # If any of validations fail ActiveRecord::RecordInvalid gets raised.
        # If any of the before_* callbacks return false the action is cancelled and save! raises ActiveRecord::RecordNotSaved.
        begin
          row.persist
        rescue ActiveRecord::RecordInvalid => e
          row.record_with_error = e.record
          collection.invalid_row = row
          rollback
        rescue ActiveRecord::RecordNotSaved => e
          row.model_with_error = e.record
          collection.invalid_row = row
          rollback
        end
      end
    end
  end
end

.read(spreadsheet_file) ⇒ Object

Read and validates the given #spreadsheet_file. Persistence is triggered after all validation pass

Parameters:

spreadsheet_file

File instance

Returns:

row_collection

SpreadsheetReader::RowCollection instance



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# File 'lib/rails_spreadsheet_reader/base.rb', line 184

def self.read(spreadsheet_file)

  if headers.empty?
    raise MethodNotImplementedError
  end

  spreadsheet = open(spreadsheet_file)
  collection = RailsSpreadsheetReader::RowCollection.new

  # Populate collection
  (starting_row..spreadsheet.last_row).each do |row_number|
    parameters = formatted_hash(spreadsheet.row(row_number))
    parameters[:row_number] = row_number
    parameters[:collection] = collection
    collection << self.new(parameters)
  end

  # Validation and persist
  persist(collection)

  collection
end

.starting_row ⇒ Object

Defines the starting row of the excel where the class should start reading the data.

Returns:

A integer representing the starting row of the data.



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# File 'lib/rails_spreadsheet_reader/base.rb', line 65

def self.starting_row
  2
end

Instance Method Details

#check_record_with_error ⇒ Object 



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# File 'lib/rails_spreadsheet_reader/base.rb', line 24

def check_record_with_error
  if record_with_error.present? and record_with_error.errors.any?
    record_with_error.errors.full_messages.each do |msg|
      @errors.add(:base, msg)
    end
  end
end

#models ⇒ Object 



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# File 'lib/rails_spreadsheet_reader/base.rb', line 40

def models
  fail(
      MethodNotImplementedError,
      'Please implement this method in your class.'
  )
end

#persist ⇒ Object 



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# File 'lib/rails_spreadsheet_reader/base.rb', line 47

def persist
  models = self.class.models.is_a?(Array) ? self.class.models : [self.class.models]
  models.each do |model|
    method_name = model.model_name.human.downcase
    if respond_to?(method_name)
      instance = model.new(send(model.model_name.human.downcase))
    else
      instance = model.new(as_json(except: BASE_ATTRIBUTES))
    end
    instance.save!
  end
end