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Cucumber::Ast::Table

Step Definitions that match a plain text Step with a multiline argument table will receive it as an instance of Table. A Table object holds the data of a table parsed from a feature file and lets you access and manipulate the data in different ways.

For example:

Given I have:
  | a | b |
  | c | d |

And a matching StepDefinition:

Given /I have:/ do |table|
  data = table.raw
end

This will store [['a', 'b'], ['c', 'd']] in the data variable.

Attributes

file[RW]

Public Class Methods

new(raw, conversion_procs = NULL_CONVERSIONS.dup) click to toggle source

Creates a new instance. raw should be an Array of Array of String or an Array of Hash (similar to what hashes returns). You don’t typically create your own Table objects - Cucumber will do it internally and pass them to your Step Definitions.

 
               # File lib/cucumber/ast/table.rb, line 47
def initialize(raw, conversion_procs = NULL_CONVERSIONS.dup)
  @cells_class = Cells
  @cell_class = Cell

  raw = ensure_array_of_array(raw)
  # Verify that it's square
  transposed = raw.transpose
  create_cell_matrix(raw)
  @conversion_procs = conversion_procs
end
            

Public Instance Methods

diff!(other_table, options={}) click to toggle source

Compares other_table to self. If other_table contains columns and/or rows that are not in self, new columns/rows are added at the relevant positions, marking the cells in those rows/columns as surplus. Likewise, if other_table lacks columns and/or rows that are present in self, these are marked as missing.

surplus and missing cells are recognised by formatters and displayed so that it's easy to read the differences.

Cells that are different, but look identical (for example the boolean true and the string “true”) are converted to their Object#inspect representation and preceded with (i) - to make it easier to identify where the difference actually is.

Since all tables that are passed to StepDefinitions always have String objects in their cells, you may want to use map_column! before calling diff!. You can use map_column! on either of the tables.

A Different error is raised if there are missing rows or columns, or surplus rows. An error is not raised for surplus columns. Whether to raise or not raise can be changed by setting values in options to true or false:

  • missing_row : Raise on missing rows (defaults to true)

  • surplus_row : Raise on surplus rows (defaults to true)

  • missing_col : Raise on missing columns (defaults to true)

  • surplus_col : Raise on surplus columns (defaults to false)

The other_table argument can be another Table, an Array of Array or an Array of Hash (similar to the structure returned by hashes).

Calling this method is particularly useful in Then steps that take a Table argument, if you want to compare that table to some actual values.

 
               # File lib/cucumber/ast/table.rb, line 282
def diff!(other_table, options={})
  options = {:missing_row => true, :surplus_row => true, :missing_col => true, :surplus_col => false}.merge(options)

  other_table = ensure_table(other_table)
  other_table.convert_columns!
  ensure_green!

  original_width = cell_matrix[0].length
  other_table_cell_matrix = pad!(other_table.cell_matrix)
  padded_width = cell_matrix[0].length

  missing_col = cell_matrix[0].detect{|cell| cell.status == :undefined}
  surplus_col = padded_width > original_width

  require_diff_lcs
  cell_matrix.extend(Diff::LCS)
  convert_columns!
  changes = cell_matrix.diff(other_table_cell_matrix).flatten

  inserted = 0
  missing  = 0

  row_indices = Array.new(other_table_cell_matrix.length) {|n| n}

  last_change = nil
  missing_row_pos = nil
  insert_row_pos  = nil
  
  changes.each do |change|
    if(change.action == '-')
      missing_row_pos = change.position + inserted
      cell_matrix[missing_row_pos].each{|cell| cell.status = :undefined}
      row_indices.insert(missing_row_pos, nil)
      missing += 1
    else # '+'
      insert_row_pos = change.position + missing
      inserted_row = change.element
      inserted_row.each{|cell| cell.status = :comment}
      cell_matrix.insert(insert_row_pos, inserted_row)
      row_indices[insert_row_pos] = nil
      inspect_rows(cell_matrix[missing_row_pos], inserted_row) if last_change && last_change.action == '-'
      inserted += 1
    end
    last_change = change
  end

  other_table_cell_matrix.each_with_index do |other_row, i|
    row_index = row_indices.index(i)
    row = cell_matrix[row_index] if row_index
    if row
      (original_width..padded_width).each do |col_index|
        surplus_cell = other_row[col_index]
        row[col_index].value = surplus_cell.value if row[col_index]
      end
    end
  end
  
  clear_cache!
  should_raise = 
    missing_row_pos && options[:missing_row] ||
    insert_row_pos  && options[:surplus_row] ||
    missing_col     && options[:missing_col] ||
    surplus_col     && options[:surplus_col]
  raise Different.new(self) if should_raise
end
            
dup() click to toggle source

Creates a copy of this table, inheriting any column mappings. registered with map_headers!

 
               # File lib/cucumber/ast/table.rb, line 61
def dup
  self.class.new(raw.dup, @conversion_procs.dup)
end
            
hashes() click to toggle source

Converts this table into an Array of Hash where the keys of each Hash are the headers in the table. For example, a Table built from the following plain text:

| a | b | sum |
| 2 | 3 | 5   |
| 7 | 9 | 16  |

Gets converted into the following:

[{'a' => '2', 'b' => '3', 'sum' => '5'}, {'a' => '7', 'b' => '9', 'sum' => '16'}]

Use map_column! to specify how values in a column are converted.

 
               # File lib/cucumber/ast/table.rb, line 94
def hashes
  @hashes ||= cells_rows[1..-1].map do |row|
    row.to_hash
  end
end
            
map_column!(column_name, strict=true, &conversion_proc) click to toggle source

Change how hashes converts column values. The column_name argument identifies the column and conversion_proc performs the conversion for each cell in that column. If strict is true, an error will be raised if the column named column_name is not found. If strict is false, no error will be raised. Example:

Given /^an expense report for (.*) with the following posts:$/ do |table|
  posts_table.map_column!('amount') { |a| a.to_i }
  posts_table.hashes.each do |post|
    # post['amount'] is a Fixnum, rather than a String
  end
end
 
               # File lib/cucumber/ast/table.rb, line 243
def map_column!(column_name, strict=true, &conversion_proc)
  verify_column(column_name) if strict
  @conversion_procs[column_name] = conversion_proc
end
            
map_headers(mappings={}) click to toggle source

Returns a new Table where the headers are redefined. See map_headers!

 
               # File lib/cucumber/ast/table.rb, line 225
def map_headers(mappings={})
  table = self.dup
  table.map_headers!(mappings)
  table
end
            
map_headers!(mappings={}, &block) click to toggle source

Redefines the table headers. This makes it possible to use prettier and more flexible header names in the features. The keys of mappings are Strings or regular expressions (anything that responds to === will work) that may match column headings in the table. The values of mappings are desired names for the columns.

Example:

| Phone Number | Address |
| 123456       | xyz     |
| 345678       | abc     |

A StepDefinition receiving this table can then map the columns with both Regexp and String:

table.map_headers!(/phone( number)?/ => :phone, 'Address' => :address)
table.hashes
# => [{:phone => '123456', :address => 'xyz'}, {:phone => '345678', :address => 'abc'}]

You may also pass in a block if you wish to convert all of the headers:

table.map_headers! { |header| header.downcase }
table.hashes.keys
# => ['phone number', 'address']

When a block is passed in along with a hash then the mappings in the hash take precendence:

table.map_headers!('Address' => 'ADDRESS') { |header| header.downcase }
table.hashes.keys
# => ['phone number', 'ADDRESS']
 
               # File lib/cucumber/ast/table.rb, line 205
def map_headers!(mappings={}, &block)
  header_cells = cell_matrix[0]

  if block_given?
    header_values = header_cells.map { |cell| cell.value } - mappings.keys
    mappings = mappings.merge(Hash[*header_values.zip(header_values.map(&block)).flatten])
  end

  mappings.each_pair do |pre, post|
    mapped_cells = header_cells.select{|cell| pre === cell.value}
    raise "No headers matched #{pre.inspect}" if mapped_cells.empty?
    raise "#{mapped_cells.length} headers matched #{pre.inspect}: #{mapped_cells.map{|c| c.value}.inspect}" if mapped_cells.length > 1
    mapped_cells[0].value = post
    if @conversion_procs.has_key?(pre)
      @conversion_procs[post] = @conversion_procs.delete(pre)
    end
  end
end
            
match(pattern) click to toggle source

Matches pattern against the header row of the table. This is used especially for argument transforms.

Example:

| column_1_name | column_2_name |
| x             | y             |

table.match(/table:column_1_name,column_2_name/) #=> non-nil

Note: must use ‘table:’ prefix on match

 
               # File lib/cucumber/ast/table.rb, line 163
def match(pattern)
  header_to_match = "table:#{headers.join(',')}"
  pattern.match(header_to_match)
end
            
raw() click to toggle source

Gets the raw data of this table. For example, a Table built from the following plain text:

| a | b |
| c | d |

gets converted into the following:

[['a', 'b], ['c', 'd']]
 
               # File lib/cucumber/ast/table.rb, line 128
def raw
  cell_matrix.map do |row|
    row.map do |cell|
      cell.value
    end
  end
end
            
rows() click to toggle source

Same as raw, but skips the first (header) row

 
               # File lib/cucumber/ast/table.rb, line 137
def rows
  raw[1..-1]
end
            
rows_hash() click to toggle source

Converts this table into a Hash where the first column is used as keys and the second column is used as values

| a | 2 |
| b | 3 |

Gets converted into the following:

{'a' => '2', 'b' => '3'}

The table must be exactly two columns wide

 
               # File lib/cucumber/ast/table.rb, line 112
def rows_hash
  return @rows_hash if @rows_hash
  verify_table_width(2)
  @rows_hash = self.transpose.hashes[0]
end
            
transpose() click to toggle source

Returns a new, transposed table. Example:

| a | 7 | 4 |
| b | 9 | 2 |

Gets converted into the following:

| a | b |
| 7 | 9 |
| 4 | 2 |
 
               # File lib/cucumber/ast/table.rb, line 76
def transpose
  self.class.new(raw.transpose, @conversion_procs.dup)
end
            

Protected Instance Methods

ensure_array_of_array(array) click to toggle source
 
               # File lib/cucumber/ast/table.rb, line 533
def ensure_array_of_array(array)
  Hash === array[0] ? hashes_to_array(array) : array
end