Class: HoneyFormat::Header

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/honey_format/matrix/header.rb

Overview

Represents a header

Instance Method Summary collapse

Constructor Details

#initialize(header, converter: HoneyFormat.header_converter, deduplicator: HoneyFormat.config.header_deduplicator) ⇒ Header

Instantiate a Header

Examples:

Instantiate a header with a custom converter

converter = ->(col) { col == 'username' ? 'handle' : col }
header = HoneyFormat::Header.new(['name', 'username'], converter: converter)
header.to_a # => ['name', 'handle']

Parameters:

  • header (Array<String>) —

    array of strings.

  • converter (#call, Symbol, Hash) (defaults to: HoneyFormat.header_converter) —

    header converter that implements a #call method that takes one column (string) argument OR symbol for a registered converter registry OR a hash mapped to a symbol or something that responds to #call.

  • deduplicator (#call, Symbol) (defaults to: HoneyFormat.config.header_deduplicator) —

    header deduplicator that implements a #call method that takes columns Array<String> argument OR symbol for a registered deduplicator registry.

Raises:



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# File 'lib/honey_format/matrix/header.rb', line 28

def initialize(
  header,
  converter: HoneyFormat.header_converter,
  deduplicator: HoneyFormat.config.header_deduplicator
)
  if header.nil? || header.empty?
    raise(Errors::MissingHeaderError, "CSV header can't be empty.")
  end

  @original_header = header
  self.deduplicator = deduplicator
  self.converter = converter
  @columns = build_columns(@original_header)
end

Instance Method Details

#columns ⇒ Array<Symbol>

Returns columns as array.

Returns:

  • (Array<Symbol>) —

    of columns.



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# File 'lib/honey_format/matrix/header.rb', line 65

def columns
  @columns
end

#each {|row| ... } ⇒ Enumerator

Returns If no block is given, an enumerator object will be returned.

Yields:

  • (row) —

    The given block will be passed for every column.

Yield Parameters:

  • a (Row) —

    column in the CSV header.

Returns:

  • (Enumerator) —

    If no block is given, an enumerator object will be returned.



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# File 'lib/honey_format/matrix/header.rb', line 59

def each(&block)
  columns.each(&block)
end

#empty? ⇒ true, false

Returns true if columns contains no elements.

Returns:

  • (true, false) —

    true if columns contains no elements.



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# File 'lib/honey_format/matrix/header.rb', line 51

def empty?
  @columns.empty?
end

#length ⇒ Integer Also known as: size

Return the number of header columns

Returns:

  • (Integer) —

    the number of header columns



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# File 'lib/honey_format/matrix/header.rb', line 77

def length
  columns.length
end

#original ⇒ Array<String>

Returns the original header

Returns:

  • (Array<String>) —

    the original header



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# File 'lib/honey_format/matrix/header.rb', line 45

def original
  @original_header
end

#to_a ⇒ Array<Symbol>

Returns columns as array.

Returns:

  • (Array<Symbol>) —

    of columns.



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# File 'lib/honey_format/matrix/header.rb', line 71

def to_a
  columns
end

#to_csv(columns: nil) ⇒ String

Header as CSV-string

Returns:

  • (String) —

    CSV-string representation.



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# File 'lib/honey_format/matrix/header.rb', line 84

def to_csv(columns: nil)
  attributes = if columns
                 self.columns & columns.map(&:to_sym)
               else
                 self.columns
               end

  ::CSV.generate_line(attributes)
end