Validators

You can define 3 kind of validators:

1 - File Validators

These validators will run against your xls/csv file.

The built in file validators are:

• File format *

  class SuperheroesParser < Parxer::XlsParser
    validate_file(:file_format, allowed_extensions: [:xls, :xlsx]) # [:csv] with CsvParser
  end

  If you are working with an xls parser and try to upload for example a .doc file, you will get an error.

• File presence *

  class SuperheroesParser < Parxer::XlsParser
    validate_file(:file_presence)
  end

  If you do not upload the file, you will get an error.

• Rows count

  class SuperheroesParser < Parxer::XlsParser
    validate_file(:rows_count, max: 50)
  end

  If you exceed the number of rows to update (50), you will get an error.

• Header order

  class SuperheroesParser < Parxer::XlsParser
    validate_file(:header_order)
  end

  The order is defined by the execution order of the column method. If you have for example:

  class SuperheroesParser < Parxer::XlsParser
    validate_file(:header_order)
  
    column(:name, name: "Name")
    column(:super_power, name: "Super Power")
    column(:publisher, name: "Publisher")
  end

  You will need to upload a xls file with "Name" as first column, "Super Power" as second and "Publisher" as third or you will get an error.

Validators marked with * are included by default in XlsParser and CsvParser parsers.

2 - Column Validators

These validators will run against each cell of your xls/csv file and need to be defined in column context.

The built in file validators are:

• Presence

  class SuperheroesParser < Parxer::XlsParser
    column(:name, name: "Name") do
      validate(:presence)
    end
  end

  Following the previous example, if you have an empty cell under the "Name" column you will get an error.

• Boolean

  class SuperheroesParser < Parxer::XlsParser
    column(:alive, name: "Alive") do
      validate(:boolean)
    end
  end

  According to the previous example, if you have a cell under the "Alive" column with a value different from any of the following: true, "true", "t", "1", false, "false", "f", "0" you will get an error.

• Email

  class SuperheroesParser < Parxer::XlsParser
    column(:email, name: "E-Mail") do
      validate(:email)
    end
  end

  Following the previous example, if you have an invalid email under the "E-mail" column you will get an error.

• URL

  class SuperheroesParser < Parxer::XlsParser
    column(:site_url, name: "Site URL") do
      validate(:url)
    end
  end

  Following the previous example, if you have an invalid URL under the "Site URL" column you will get an error.

• Chilean RUT

  class SuperheroesParser < Parxer::XlsParser
    column(:rut, name: "RUT") do
      validate(:rut)
    end
  end

  Following the previous example, if you have an invalid RUT under the "RUT" column you will get an error.

• Inclusion

  class SuperheroesParser < Parxer::XlsParser
    column(:publisher, name: "Publisher") do
      validate(:inclusion, in: ["Marvel", "DC"])
    end
  end

  According to the previous example, if you have a cell under the "Publisher" column with a value different from any of the following: "Marvel", "DC" you will get an error.

• Datetime

  class SuperheroesParser < Parxer::XlsParser
    column(:created_at, name: "Created At") do
      validate(:datetime, options)
    end
  end

  Options:

  • format: to ensure specific date/time format. If you have for example: validate(:datetime, format: "%Y%M"), you will need to provide "Created At" values like this: "201812".
  • gt: to ensure date/times greater than the given value. For example: validate(:datetime, gt: DateTime.current)
  • gteq: to ensure date/times greater than or equal to the given value.
  • lt: to ensure date/times lower than the given value.
  • lteq: to ensure date/times lower than or equal to the given value.

• Number

  class SuperheroesParser < Parxer::XlsParser
    column(:age, name: "Age") do
      validate(:number, options)
    end
  end

  Options:

  • only_integer: to ensure Integer values. If you have for example: validate(:number, only_integer: true)
  • allow_negative: set to false if you want to work with positive values only. If you have for example: validate(:number, allow_negative: false)
  • gt, gteq, lt and lteq: the same as with the dates.

3 - Row Validators

These validators will run after Column Validators if all the cells in the row are valid.

class SuperheroesParser < Parxer::XlsParser
  column(:name, name: "Name")
    validate(:presence)
  end

  column(:real_name, name: "Real Name") do
    validate(:presence)
  end

  validate_row(:odd_chars, options) do
    (row.name + row.real_name).delete(" ").size.odd?
  end
end

According to the previous example, the custom odd_chars row validator will run after running presence column validators defined for name and real_name columns. Inside the validate_row's block you need to define a conditional.

You can access row attributes using the row method if you need.

Options:

• if_valid: by default row validators will run if all the cells in the row are valid. But, you can set the if_valid option execute the validator if one or more cells are valid. For example: validate_row(:odd_chars, if_valid: [:name, :real_name]). So, on this case, the validator will run if "Name" and "Real Name" are valid.

Custom validators

You can define 2 kind of custom validators:

• Inline Validators:

  This kind of validators take a name (:odd_string) and a block. The block needs to hold a conditional. For example:

  class SuperheroesParser < Parxer::XlsParser
    column(:name, name: "Name")
      validate(:odd_string) do
        value.to_s.odd?
      end
    end
  end

• Reusable Validators:

  If you want to reuse a validator, you can create one like this:

  module Parxer
    module Validator
      class OddString < Base
        def validate
          value.to_s.odd?
        end
      end
    end
  end

  And then you can use it like this:

  class SuperheroesParser < Parxer::XlsParser
    column(:name, name: "Name")
      validate(:odd_string)
    end
  
    column(:publisher, name: "Publisher") do
      validate(:odd_string)
    end
  end

You can use Custom validators with row and file validators too