kolan
/
Redmine
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
Redmine/lib/faster_csv.rb

1985 lines
69 KiB
Ruby
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#!/usr/local/bin/ruby -w
# = faster_csv.rb -- Faster CSV Reading and Writing
#
# Created by James Edward Gray II on 2005-10-31.
# Copyright 2005 Gray Productions. All rights reserved.
#
# See FasterCSV for documentation.
if RUBY_VERSION >= "1.9"
abort <<-VERSION_WARNING.gsub(/^\s+/, "")
Please switch to Ruby 1.9's standard CSV library. It's FasterCSV plus
support for Ruby 1.9's m17n encoding engine.
VERSION_WARNING
end
require "forwardable"
require "English"
require "enumerator"
require "date"
require "stringio"
#
# This class provides a complete interface to CSV files and data. It offers
# tools to enable you to read and write to and from Strings or IO objects, as
# needed.
#
# == Reading
#
# === From a File
#
# ==== A Line at a Time
#
# FasterCSV.foreach("path/to/file.csv") do |row|
# # use row here...
# end
#
# ==== All at Once
#
# arr_of_arrs = FasterCSV.read("path/to/file.csv")
#
# === From a String
#
# ==== A Line at a Time
#
# FasterCSV.parse("CSV,data,String") do |row|
# # use row here...
# end
#
# ==== All at Once
#
# arr_of_arrs = FasterCSV.parse("CSV,data,String")
#
# == Writing
#
# === To a File
#
# FasterCSV.open("path/to/file.csv", "w") do |csv|
# csv << ["row", "of", "CSV", "data"]
# csv << ["another", "row"]
# # ...
# end
#
# === To a String
#
# csv_string = FasterCSV.generate do |csv|
# csv << ["row", "of", "CSV", "data"]
# csv << ["another", "row"]
# # ...
# end
#
# == Convert a Single Line
#
# csv_string = ["CSV", "data"].to_csv # to CSV
# csv_array = "CSV,String".parse_csv # from CSV
#
# == Shortcut Interface
#
# FCSV { |csv_out| csv_out << %w{my data here} } # to $stdout
# FCSV(csv = "") { |csv_str| csv_str << %w{my data here} } # to a String
# FCSV($stderr) { |csv_err| csv_err << %w{my data here} } # to $stderr
#
class FasterCSV
# The version of the installed library.
VERSION = "1.5.0".freeze
#
# A FasterCSV::Row is part Array and part Hash. It retains an order for the
# fields and allows duplicates just as an Array would, but also allows you to
# access fields by name just as you could if they were in a Hash.
#
# All rows returned by FasterCSV will be constructed from this class, if
# header row processing is activated.
#
class Row
#
# Construct a new FasterCSV::Row from +headers+ and +fields+, which are
# expected to be Arrays. If one Array is shorter than the other, it will be
# padded with +nil+ objects.
#
# The optional +header_row+ parameter can be set to +true+ to indicate, via
# FasterCSV::Row.header_row?() and FasterCSV::Row.field_row?(), that this is
# a header row. Otherwise, the row is assumes to be a field row.
#
# A FasterCSV::Row object supports the following Array methods through
# delegation:
#
# * empty?()
# * length()
# * size()
#
def initialize(headers, fields, header_row = false)
@header_row = header_row
# handle extra headers or fields
@row = if headers.size > fields.size
headers.zip(fields)
else
fields.zip(headers).map { |pair| pair.reverse }
end
end
# Internal data format used to compare equality.
attr_reader :row
protected :row
### Array Delegation ###
extend Forwardable
def_delegators :@row, :empty?, :length, :size
# Returns +true+ if this is a header row.
def header_row?
@header_row
end
# Returns +true+ if this is a field row.
def field_row?
not header_row?
end
# Returns the headers of this row.
def headers
@row.map { |pair| pair.first }
end
#
# :call-seq:
# field( header )
# field( header, offset )
# field( index )
#
# This method will fetch the field value by +header+ or +index+. If a field
# is not found, +nil+ is returned.
#
# When provided, +offset+ ensures that a header match occurrs on or later
# than the +offset+ index. You can use this to find duplicate headers,
# without resorting to hard-coding exact indices.
#
def field(header_or_index, minimum_index = 0)
# locate the pair
finder = header_or_index.is_a?(Integer) ? :[] : :assoc
pair = @row[minimum_index..-1].send(finder, header_or_index)
# return the field if we have a pair
pair.nil? ? nil : pair.last
end
alias_method :[], :field
#
# :call-seq:
# []=( header, value )
# []=( header, offset, value )
# []=( index, value )
#
# Looks up the field by the semantics described in FasterCSV::Row.field()
# and assigns the +value+.
#
# Assigning past the end of the row with an index will set all pairs between
# to <tt>[nil, nil]</tt>. Assigning to an unused header appends the new
# pair.
#
def []=(*args)
value = args.pop
if args.first.is_a? Integer
if @row[args.first].nil? # extending past the end with index
@row[args.first] = [nil, value]
@row.map! { |pair| pair.nil? ? [nil, nil] : pair }
else # normal index assignment
@row[args.first][1] = value
end
else
index = index(*args)
if index.nil? # appending a field
self << [args.first, value]
else # normal header assignment
@row[index][1] = value
end
end
end
#
# :call-seq:
# <<( field )
# <<( header_and_field_array )
# <<( header_and_field_hash )
#
# If a two-element Array is provided, it is assumed to be a header and field
# and the pair is appended. A Hash works the same way with the key being
# the header and the value being the field. Anything else is assumed to be
# a lone field which is appended with a +nil+ header.
#
# This method returns the row for chaining.
#
def <<(arg)
if arg.is_a?(Array) and arg.size == 2 # appending a header and name
@row << arg
elsif arg.is_a?(Hash) # append header and name pairs
arg.each { |pair| @row << pair }
else # append field value
@row << [nil, arg]
end
self # for chaining
end
#
# A shortcut for appending multiple fields. Equivalent to:
#
# args.each { |arg| faster_csv_row << arg }
#
# This method returns the row for chaining.
#
def push(*args)
args.each { |arg| self << arg }
self # for chaining
end
#
# :call-seq:
# delete( header )
# delete( header, offset )
# delete( index )
#
# Used to remove a pair from the row by +header+ or +index+. The pair is
# located as described in FasterCSV::Row.field(). The deleted pair is
# returned, or +nil+ if a pair could not be found.
#
def delete(header_or_index, minimum_index = 0)
if header_or_index.is_a? Integer # by index
@row.delete_at(header_or_index)
else # by header
@row.delete_at(index(header_or_index, minimum_index))
end
end
#
# The provided +block+ is passed a header and field for each pair in the row
# and expected to return +true+ or +false+, depending on whether the pair
# should be deleted.
#
# This method returns the row for chaining.
#
def delete_if(&block)
@row.delete_if(&block)
self # for chaining
end
#
# This method accepts any number of arguments which can be headers, indices,
# Ranges of either, or two-element Arrays containing a header and offset.
# Each argument will be replaced with a field lookup as described in
# FasterCSV::Row.field().
#
# If called with no arguments, all fields are returned.
#
def fields(*headers_and_or_indices)
if headers_and_or_indices.empty? # return all fields--no arguments
@row.map { |pair| pair.last }
else # or work like values_at()
headers_and_or_indices.inject(Array.new) do |all, h_or_i|
all + if h_or_i.is_a? Range
index_begin = h_or_i.begin.is_a?(Integer) ? h_or_i.begin :
index(h_or_i.begin)
index_end = h_or_i.end.is_a?(Integer) ? h_or_i.end :
index(h_or_i.end)
new_range = h_or_i.exclude_end? ? (index_begin...index_end) :
(index_begin..index_end)
fields.values_at(new_range)
else
[field(*Array(h_or_i))]
end
end
end
end
alias_method :values_at, :fields
#
# :call-seq:
# index( header )
# index( header, offset )
#
# This method will return the index of a field with the provided +header+.
# The +offset+ can be used to locate duplicate header names, as described in
# FasterCSV::Row.field().
#
def index(header, minimum_index = 0)
# find the pair
index = headers[minimum_index..-1].index(header)
# return the index at the right offset, if we found one
index.nil? ? nil : index + minimum_index
end
# Returns +true+ if +name+ is a header for this row, and +false+ otherwise.
def header?(name)
headers.include? name
end
alias_method :include?, :header?
#
# Returns +true+ if +data+ matches a field in this row, and +false+
# otherwise.
#
def field?(data)
fields.include? data
end
include Enumerable
#
# Yields each pair of the row as header and field tuples (much like
# iterating over a Hash).
#
# Support for Enumerable.
#
# This method returns the row for chaining.
#
def each(&block)
@row.each(&block)
self # for chaining
end
#
# Returns +true+ if this row contains the same headers and fields in the
# same order as +other+.
#
def ==(other)
@row == other.row
end
#
# Collapses the row into a simple Hash. Be warning that this discards field
# order and clobbers duplicate fields.
#
def to_hash
# flatten just one level of the internal Array
Hash[*@row.inject(Array.new) { |ary, pair| ary.push(*pair) }]
end
#
# Returns the row as a CSV String. Headers are not used. Equivalent to:
#
# faster_csv_row.fields.to_csv( options )
#
def to_csv(options = Hash.new)
fields.to_csv(options)
end
alias_method :to_s, :to_csv
# A summary of fields, by header.
def inspect
str = "#<#{self.class}"
each do |header, field|
str << " #{header.is_a?(Symbol) ? header.to_s : header.inspect}:" <<
field.inspect
end
str << ">"
end
end
#
# A FasterCSV::Table is a two-dimensional data structure for representing CSV
# documents. Tables allow you to work with the data by row or column,
# manipulate the data, and even convert the results back to CSV, if needed.
#
# All tables returned by FasterCSV will be constructed from this class, if
# header row processing is activated.
#
class Table
#
# Construct a new FasterCSV::Table from +array_of_rows+, which are expected
# to be FasterCSV::Row objects. All rows are assumed to have the same
# headers.
#
# A FasterCSV::Table object supports the following Array methods through
# delegation:
#
# * empty?()
# * length()
# * size()
#
def initialize(array_of_rows)
@table = array_of_rows
@mode = :col_or_row
end
# The current access mode for indexing and iteration.
attr_reader :mode
# Internal data format used to compare equality.
attr_reader :table
protected :table
### Array Delegation ###
extend Forwardable
def_delegators :@table, :empty?, :length, :size
#
# Returns a duplicate table object, in column mode. This is handy for
# chaining in a single call without changing the table mode, but be aware
# that this method can consume a fair amount of memory for bigger data sets.
#
# This method returns the duplicate table for chaining. Don't chain
# destructive methods (like []=()) this way though, since you are working
# with a duplicate.
#
def by_col
self.class.new(@table.dup).by_col!
end
#
# Switches the mode of this table to column mode. All calls to indexing and
# iteration methods will work with columns until the mode is changed again.
#
# This method returns the table and is safe to chain.
#
def by_col!
@mode = :col
self
end
#
# Returns a duplicate table object, in mixed mode. This is handy for
# chaining in a single call without changing the table mode, but be aware
# that this method can consume a fair amount of memory for bigger data sets.
#
# This method returns the duplicate table for chaining. Don't chain
# destructive methods (like []=()) this way though, since you are working
# with a duplicate.
#
def by_col_or_row
self.class.new(@table.dup).by_col_or_row!
end
#
# Switches the mode of this table to mixed mode. All calls to indexing and
# iteration methods will use the default intelligent indexing system until
# the mode is changed again. In mixed mode an index is assumed to be a row
# reference while anything else is assumed to be column access by headers.
#
# This method returns the table and is safe to chain.
#
def by_col_or_row!
@mode = :col_or_row
self
end
#
# Returns a duplicate table object, in row mode. This is handy for chaining
# in a single call without changing the table mode, but be aware that this
# method can consume a fair amount of memory for bigger data sets.
#
# This method returns the duplicate table for chaining. Don't chain
# destructive methods (like []=()) this way though, since you are working
# with a duplicate.
#
def by_row
self.class.new(@table.dup).by_row!
end
#
# Switches the mode of this table to row mode. All calls to indexing and
# iteration methods will work with rows until the mode is changed again.
#
# This method returns the table and is safe to chain.
#
def by_row!
@mode = :row
self
end
#
# Returns the headers for the first row of this table (assumed to match all
# other rows). An empty Array is returned for empty tables.
#
def headers
if @table.empty?
Array.new
else
@table.first.headers
end
end
#
# In the default mixed mode, this method returns rows for index access and
# columns for header access. You can force the index association by first
# calling by_col!() or by_row!().
#
# Columns are returned as an Array of values. Altering that Array has no
# effect on the table.
#
def [](index_or_header)
if @mode == :row or # by index
(@mode == :col_or_row and index_or_header.is_a? Integer)
@table[index_or_header]
else # by header
@table.map { |row| row[index_or_header] }
end
end
#
# In the default mixed mode, this method assigns rows for index access and
# columns for header access. You can force the index association by first
# calling by_col!() or by_row!().
#
# Rows may be set to an Array of values (which will inherit the table's
# headers()) or a FasterCSV::Row.
#
# Columns may be set to a single value, which is copied to each row of the
# column, or an Array of values. Arrays of values are assigned to rows top
# to bottom in row major order. Excess values are ignored and if the Array
# does not have a value for each row the extra rows will receive a +nil+.
#
# Assigning to an existing column or row clobbers the data. Assigning to
# new columns creates them at the right end of the table.
#
def []=(index_or_header, value)
if @mode == :row or # by index
(@mode == :col_or_row and index_or_header.is_a? Integer)
if value.is_a? Array
@table[index_or_header] = Row.new(headers, value)
else
@table[index_or_header] = value
end
else # set column
if value.is_a? Array # multiple values
@table.each_with_index do |row, i|
if row.header_row?
row[index_or_header] = index_or_header
else
row[index_or_header] = value[i]
end
end
else # repeated value
@table.each do |row|
if row.header_row?
row[index_or_header] = index_or_header
else
row[index_or_header] = value
end
end
end
end
end
#
# The mixed mode default is to treat a list of indices as row access,
# returning the rows indicated. Anything else is considered columnar
# access. For columnar access, the return set has an Array for each row
# with the values indicated by the headers in each Array. You can force
# column or row mode using by_col!() or by_row!().
#
# You cannot mix column and row access.
#
def values_at(*indices_or_headers)
if @mode == :row or # by indices
( @mode == :col_or_row and indices_or_headers.all? do |index|
index.is_a?(Integer) or
( index.is_a?(Range) and
index.first.is_a?(Integer) and
index.last.is_a?(Integer) )
end )
@table.values_at(*indices_or_headers)
else # by headers
@table.map { |row| row.values_at(*indices_or_headers) }
end
end
#
# Adds a new row to the bottom end of this table. You can provide an Array,
# which will be converted to a FasterCSV::Row (inheriting the table's
# headers()), or a FasterCSV::Row.
#
# This method returns the table for chaining.
#
def <<(row_or_array)
if row_or_array.is_a? Array # append Array
@table << Row.new(headers, row_or_array)
else # append Row
@table << row_or_array
end
self # for chaining
end
#
# A shortcut for appending multiple rows. Equivalent to:
#
# rows.each { |row| self << row }
#
# This method returns the table for chaining.
#
def push(*rows)
rows.each { |row| self << row }
self # for chaining
end
#
# Removes and returns the indicated column or row. In the default mixed
# mode indices refer to rows and everything else is assumed to be a column
# header. Use by_col!() or by_row!() to force the lookup.
#
def delete(index_or_header)
if @mode == :row or # by index
(@mode == :col_or_row and index_or_header.is_a? Integer)
@table.delete_at(index_or_header)
else # by header
@table.map { |row| row.delete(index_or_header).last }
end
end
#
# Removes any column or row for which the block returns +true+. In the
# default mixed mode or row mode, iteration is the standard row major
# walking of rows. In column mode, interation will +yield+ two element
# tuples containing the column name and an Array of values for that column.
#
# This method returns the table for chaining.
#
def delete_if(&block)
if @mode == :row or @mode == :col_or_row # by index
@table.delete_if(&block)
else # by header
to_delete = Array.new
headers.each_with_index do |header, i|
to_delete << header if block[[header, self[header]]]
end
to_delete.map { |header| delete(header) }
end
self # for chaining
end
include Enumerable
#
# In the default mixed mode or row mode, iteration is the standard row major
# walking of rows. In column mode, interation will +yield+ two element
# tuples containing the column name and an Array of values for that column.
#
# This method returns the table for chaining.
#
def each(&block)
if @mode == :col
headers.each { |header| block[[header, self[header]]] }
else
@table.each(&block)
end
self # for chaining
end
# Returns +true+ if all rows of this table ==() +other+'s rows.
def ==(other)
@table == other.table
end
#
# Returns the table as an Array of Arrays. Headers will be the first row,
# then all of the field rows will follow.
#
def to_a
@table.inject([headers]) do |array, row|
if row.header_row?
array
else
array + [row.fields]
end
end
end
#
# Returns the table as a complete CSV String. Headers will be listed first,
# then all of the field rows.
#
def to_csv(options = Hash.new)
@table.inject([headers.to_csv(options)]) do |rows, row|
if row.header_row?
rows
else
rows + [row.fields.to_csv(options)]
end
end.join
end
alias_method :to_s, :to_csv
def inspect
"#<#{self.class} mode:#{@mode} row_count:#{to_a.size}>"
end
end
# The error thrown when the parser encounters illegal CSV formatting.
class MalformedCSVError < RuntimeError; end
#
# A FieldInfo Struct contains details about a field's position in the data
# source it was read from. FasterCSV will pass this Struct to some blocks
# that make decisions based on field structure. See
# FasterCSV.convert_fields() for an example.
#
# <b><tt>index</tt></b>:: The zero-based index of the field in its row.
# <b><tt>line</tt></b>:: The line of the data source this row is from.
# <b><tt>header</tt></b>:: The header for the column, when available.
#
FieldInfo = Struct.new(:index, :line, :header)
# A Regexp used to find and convert some common Date formats.
DateMatcher = / \A(?: (\w+,?\s+)?\w+\s+\d{1,2},?\s+\d{2,4} |
\d{4}-\d{2}-\d{2} )\z /x
# A Regexp used to find and convert some common DateTime formats.
DateTimeMatcher =
/ \A(?: (\w+,?\s+)?\w+\s+\d{1,2}\s+\d{1,2}:\d{1,2}:\d{1,2},?\s+\d{2,4} |
\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:\d{2} )\z /x
#
# This Hash holds the built-in converters of FasterCSV that can be accessed by
# name. You can select Converters with FasterCSV.convert() or through the
# +options+ Hash passed to FasterCSV::new().
#
# <b><tt>:integer</tt></b>:: Converts any field Integer() accepts.
# <b><tt>:float</tt></b>:: Converts any field Float() accepts.
# <b><tt>:numeric</tt></b>:: A combination of <tt>:integer</tt>
# and <tt>:float</tt>.
# <b><tt>:date</tt></b>:: Converts any field Date::parse() accepts.
# <b><tt>:date_time</tt></b>:: Converts any field DateTime::parse() accepts.
# <b><tt>:all</tt></b>:: All built-in converters. A combination of
# <tt>:date_time</tt> and <tt>:numeric</tt>.
#
# This Hash is intetionally left unfrozen and users should feel free to add
# values to it that can be accessed by all FasterCSV objects.
#
# To add a combo field, the value should be an Array of names. Combo fields
# can be nested with other combo fields.
#
Converters = { :integer => lambda { |f| Integer(f) rescue f },
:float => lambda { |f| Float(f) rescue f },
:numeric => [:integer, :float],
:date => lambda { |f|
f =~ DateMatcher ? (Date.parse(f) rescue f) : f
},
:date_time => lambda { |f|
f =~ DateTimeMatcher ? (DateTime.parse(f) rescue f) : f
},
:all => [:date_time, :numeric] }
#
# This Hash holds the built-in header converters of FasterCSV that can be
# accessed by name. You can select HeaderConverters with
# FasterCSV.header_convert() or through the +options+ Hash passed to
# FasterCSV::new().
#
# <b><tt>:downcase</tt></b>:: Calls downcase() on the header String.
# <b><tt>:symbol</tt></b>:: The header String is downcased, spaces are
# replaced with underscores, non-word characters
# are dropped, and finally to_sym() is called.
#
# This Hash is intetionally left unfrozen and users should feel free to add
# values to it that can be accessed by all FasterCSV objects.
#
# To add a combo field, the value should be an Array of names. Combo fields
# can be nested with other combo fields.
#
HeaderConverters = {
:downcase => lambda { |h| h.downcase },
:symbol => lambda { |h|
h.downcase.tr(" ", "_").delete("^a-z0-9_").to_sym
}
}
#
# The options used when no overrides are given by calling code. They are:
#
# <b><tt>:col_sep</tt></b>:: <tt>","</tt>
# <b><tt>:row_sep</tt></b>:: <tt>:auto</tt>
# <b><tt>:quote_char</tt></b>:: <tt>'"'</tt>
# <b><tt>:converters</tt></b>:: +nil+
# <b><tt>:unconverted_fields</tt></b>:: +nil+
# <b><tt>:headers</tt></b>:: +false+
# <b><tt>:return_headers</tt></b>:: +false+
# <b><tt>:header_converters</tt></b>:: +nil+
# <b><tt>:skip_blanks</tt></b>:: +false+
# <b><tt>:force_quotes</tt></b>:: +false+
#
DEFAULT_OPTIONS = { :col_sep => ",",
:row_sep => :auto,
:quote_char => '"',
:converters => nil,
:unconverted_fields => nil,
:headers => false,
:return_headers => false,
:header_converters => nil,
:skip_blanks => false,
:force_quotes => false }.freeze
#
# This method will build a drop-in replacement for many of the standard CSV
# methods. It allows you to write code like:
#
# begin
# require "faster_csv"
# FasterCSV.build_csv_interface
# rescue LoadError
# require "csv"
# end
# # ... use CSV here ...
#
# This is not a complete interface with completely identical behavior.
# However, it is intended to be close enough that you won't notice the
# difference in most cases. CSV methods supported are:
#
# * foreach()
# * generate_line()
# * open()
# * parse()
# * parse_line()
# * readlines()
#
# Be warned that this interface is slower than vanilla FasterCSV due to the
# extra layer of method calls. Depending on usage, this can slow it down to
# near CSV speeds.
#
def self.build_csv_interface
Object.const_set(:CSV, Class.new).class_eval do
def self.foreach(path, rs = :auto, &block) # :nodoc:
FasterCSV.foreach(path, :row_sep => rs, &block)
end
def self.generate_line(row, fs = ",", rs = "") # :nodoc:
FasterCSV.generate_line(row, :col_sep => fs, :row_sep => rs)
end
def self.open(path, mode, fs = ",", rs = :auto, &block) # :nodoc:
if block and mode.include? "r"
FasterCSV.open(path, mode, :col_sep => fs, :row_sep => rs) do |csv|
csv.each(&block)
end
else
FasterCSV.open(path, mode, :col_sep => fs, :row_sep => rs, &block)
end
end
def self.parse(str_or_readable, fs = ",", rs = :auto, &block) # :nodoc:
FasterCSV.parse(str_or_readable, :col_sep => fs, :row_sep => rs, &block)
end
def self.parse_line(src, fs = ",", rs = :auto) # :nodoc:
FasterCSV.parse_line(src, :col_sep => fs, :row_sep => rs)
end
def self.readlines(path, rs = :auto) # :nodoc:
FasterCSV.readlines(path, :row_sep => rs)
end
end
end
#
# This method allows you to serialize an Array of Ruby objects to a String or
# File of CSV data. This is not as powerful as Marshal or YAML, but perhaps
# useful for spreadsheet and database interaction.
#
# Out of the box, this method is intended to work with simple data objects or
# Structs. It will serialize a list of instance variables and/or
# Struct.members().
#
# If you need need more complicated serialization, you can control the process
# by adding methods to the class to be serialized.
#
# A class method csv_meta() is responsible for returning the first row of the
# document (as an Array). This row is considered to be a Hash of the form
# key_1,value_1,key_2,value_2,... FasterCSV::load() expects to find a class
# key with a value of the stringified class name and FasterCSV::dump() will
# create this, if you do not define this method. This method is only called
# on the first object of the Array.
#
# The next method you can provide is an instance method called csv_headers().
# This method is expected to return the second line of the document (again as
# an Array), which is to be used to give each column a header. By default,
# FasterCSV::load() will set an instance variable if the field header starts
# with an @ character or call send() passing the header as the method name and
# the field value as an argument. This method is only called on the first
# object of the Array.
#
# Finally, you can provide an instance method called csv_dump(), which will
# be passed the headers. This should return an Array of fields that can be
# serialized for this object. This method is called once for every object in
# the Array.
#
# The +io+ parameter can be used to serialize to a File, and +options+ can be
# anything FasterCSV::new() accepts.
#
def self.dump(ary_of_objs, io = "", options = Hash.new)
obj_template = ary_of_objs.first
csv = FasterCSV.new(io, options)
# write meta information
begin
csv << obj_template.class.csv_meta
rescue NoMethodError
csv << [:class, obj_template.class]
end
# write headers
begin
headers = obj_template.csv_headers
rescue NoMethodError
headers = obj_template.instance_variables.sort
if obj_template.class.ancestors.find { |cls| cls.to_s =~ /\AStruct\b/ }
headers += obj_template.members.map { |mem| "#{mem}=" }.sort
end
end
csv << headers
# serialize each object
ary_of_objs.each do |obj|
begin
csv << obj.csv_dump(headers)
rescue NoMethodError
csv << headers.map do |var|
if var[0] == ?@
obj.instance_variable_get(var)
else
obj[var[0..-2]]
end
end
end
end
if io.is_a? String
csv.string
else
csv.close
end
end
#
# :call-seq:
# filter( options = Hash.new ) { |row| ... }
# filter( input, options = Hash.new ) { |row| ... }
# filter( input, output, options = Hash.new ) { |row| ... }
#
# This method is a convenience for building Unix-like filters for CSV data.
# Each row is yielded to the provided block which can alter it as needed.
# After the block returns, the row is appended to +output+ altered or not.
#
# The +input+ and +output+ arguments can be anything FasterCSV::new() accepts
# (generally String or IO objects). If not given, they default to
# <tt>ARGF</tt> and <tt>$stdout</tt>.
#
# The +options+ parameter is also filtered down to FasterCSV::new() after some
# clever key parsing. Any key beginning with <tt>:in_</tt> or
# <tt>:input_</tt> will have that leading identifier stripped and will only
# be used in the +options+ Hash for the +input+ object. Keys starting with
# <tt>:out_</tt> or <tt>:output_</tt> affect only +output+. All other keys
# are assigned to both objects.
#
# The <tt>:output_row_sep</tt> +option+ defaults to
# <tt>$INPUT_RECORD_SEPARATOR</tt> (<tt>$/</tt>).
#
def self.filter(*args)
# parse options for input, output, or both
in_options, out_options = Hash.new, {:row_sep => $INPUT_RECORD_SEPARATOR}
if args.last.is_a? Hash
args.pop.each do |key, value|
case key.to_s
when /\Ain(?:put)?_(.+)\Z/
in_options[$1.to_sym] = value
when /\Aout(?:put)?_(.+)\Z/
out_options[$1.to_sym] = value
else
in_options[key] = value
out_options[key] = value
end
end
end
# build input and output wrappers
input = FasterCSV.new(args.shift || ARGF, in_options)
output = FasterCSV.new(args.shift || $stdout, out_options)
# read, yield, write
input.each do |row|
yield row
output << row
end
end
#
# This method is intended as the primary interface for reading CSV files. You
# pass a +path+ and any +options+ you wish to set for the read. Each row of
# file will be passed to the provided +block+ in turn.
#
# The +options+ parameter can be anything FasterCSV::new() understands.
#
def self.foreach(path, options = Hash.new, &block)
open(path, "rb", options) do |csv|
csv.each(&block)
end
end
#
# :call-seq:
# generate( str, options = Hash.new ) { |faster_csv| ... }
# generate( options = Hash.new ) { |faster_csv| ... }
#
# This method wraps a String you provide, or an empty default String, in a
# FasterCSV object which is passed to the provided block. You can use the
# block to append CSV rows to the String and when the block exits, the
# final String will be returned.
#
# Note that a passed String *is* modfied by this method. Call dup() before
# passing if you need a new String.
#
# The +options+ parameter can be anthing FasterCSV::new() understands.
#
def self.generate(*args)
# add a default empty String, if none was given
if args.first.is_a? String
io = StringIO.new(args.shift)
io.seek(0, IO::SEEK_END)
args.unshift(io)
else
args.unshift("")
end
faster_csv = new(*args) # wrap
yield faster_csv # yield for appending
faster_csv.string # return final String
end
#
# This method is a shortcut for converting a single row (Array) into a CSV
# String.
#
# The +options+ parameter can be anthing FasterCSV::new() understands.
#
# The <tt>:row_sep</tt> +option+ defaults to <tt>$INPUT_RECORD_SEPARATOR</tt>
# (<tt>$/</tt>) when calling this method.
#
def self.generate_line(row, options = Hash.new)
options = {:row_sep => $INPUT_RECORD_SEPARATOR}.merge(options)
(new("", options) << row).string
end
#
# This method will return a FasterCSV instance, just like FasterCSV::new(),
# but the instance will be cached and returned for all future calls to this
# method for the same +data+ object (tested by Object#object_id()) with the
# same +options+.
#
# If a block is given, the instance is passed to the block and the return
# value becomes the return value of the block.
#
def self.instance(data = $stdout, options = Hash.new)
# create a _signature_ for this method call, data object and options
sig = [data.object_id] +
options.values_at(*DEFAULT_OPTIONS.keys.sort_by { |sym| sym.to_s })
# fetch or create the instance for this signature
@@instances ||= Hash.new
instance = (@@instances[sig] ||= new(data, options))
if block_given?
yield instance # run block, if given, returning result
else
instance # or return the instance
end
end
#
# This method is the reading counterpart to FasterCSV::dump(). See that
# method for a detailed description of the process.
#
# You can customize loading by adding a class method called csv_load() which
# will be passed a Hash of meta information, an Array of headers, and an Array
# of fields for the object the method is expected to return.
#
# Remember that all fields will be Strings after this load. If you need
# something else, use +options+ to setup converters or provide a custom
# csv_load() implementation.
#
def self.load(io_or_str, options = Hash.new)
csv = FasterCSV.new(io_or_str, options)
# load meta information
meta = Hash[*csv.shift]
cls = meta["class"].split("::").inject(Object) do |c, const|
c.const_get(const)
end
# load headers
headers = csv.shift
# unserialize each object stored in the file
results = csv.inject(Array.new) do |all, row|
begin
obj = cls.csv_load(meta, headers, row)
rescue NoMethodError
obj = cls.allocate
headers.zip(row) do |name, value|
if name[0] == ?@
obj.instance_variable_set(name, value)
else
obj.send(name, value)
end
end
end
all << obj
end
csv.close unless io_or_str.is_a? String
results
end
#
# :call-seq:
# open( filename, mode="rb", options = Hash.new ) { |faster_csv| ... }
# open( filename, mode="rb", options = Hash.new )
#
# This method opens an IO object, and wraps that with FasterCSV. This is
# intended as the primary interface for writing a CSV file.
#
# You may pass any +args+ Ruby's open() understands followed by an optional
# Hash containing any +options+ FasterCSV::new() understands.
#
# This method works like Ruby's open() call, in that it will pass a FasterCSV
# object to a provided block and close it when the block termminates, or it
# will return the FasterCSV object when no block is provided. (*Note*: This
# is different from the standard CSV library which passes rows to the block.
# Use FasterCSV::foreach() for that behavior.)
#
# An opened FasterCSV object will delegate to many IO methods, for
# convenience. You may call:
#
# * binmode()
# * close()
# * close_read()
# * close_write()
# * closed?()
# * eof()
# * eof?()
# * fcntl()
# * fileno()
# * flush()
# * fsync()
# * ioctl()
# * isatty()
# * pid()
# * pos()
# * reopen()
# * seek()
# * stat()
# * sync()
# * sync=()
# * tell()
# * to_i()
# * to_io()
# * tty?()
#
def self.open(*args)
# find the +options+ Hash
options = if args.last.is_a? Hash then args.pop else Hash.new end
# default to a binary open mode
args << "rb" if args.size == 1
# wrap a File opened with the remaining +args+
csv = new(File.open(*args), options)
# handle blocks like Ruby's open(), not like the CSV library
if block_given?
begin
yield csv
ensure
csv.close
end
else
csv
end
end
#
# :call-seq:
# parse( str, options = Hash.new ) { |row| ... }
# parse( str, options = Hash.new )
#
# This method can be used to easily parse CSV out of a String. You may either
# provide a +block+ which will be called with each row of the String in turn,
# or just use the returned Array of Arrays (when no +block+ is given).
#
# You pass your +str+ to read from, and an optional +options+ Hash containing
# anything FasterCSV::new() understands.
#
def self.parse(*args, &block)
csv = new(*args)
if block.nil? # slurp contents, if no block is given
begin
csv.read
ensure
csv.close
end
else # or pass each row to a provided block
csv.each(&block)
end
end
#
# This method is a shortcut for converting a single line of a CSV String into
# a into an Array. Note that if +line+ contains multiple rows, anything
# beyond the first row is ignored.
#
# The +options+ parameter can be anthing FasterCSV::new() understands.
#
def self.parse_line(line, options = Hash.new)
new(line, options).shift
end
#
# Use to slurp a CSV file into an Array of Arrays. Pass the +path+ to the
# file and any +options+ FasterCSV::new() understands.
#
def self.read(path, options = Hash.new)
open(path, "rb", options) { |csv| csv.read }
end
# Alias for FasterCSV::read().
def self.readlines(*args)
read(*args)
end
#
# A shortcut for:
#
# FasterCSV.read( path, { :headers => true,
# :converters => :numeric,
# :header_converters => :symbol }.merge(options) )
#
def self.table(path, options = Hash.new)
read( path, { :headers => true,
:converters => :numeric,
:header_converters => :symbol }.merge(options) )
end
#
# This constructor will wrap either a String or IO object passed in +data+ for
# reading and/or writing. In addition to the FasterCSV instance methods,
# several IO methods are delegated. (See FasterCSV::open() for a complete
# list.) If you pass a String for +data+, you can later retrieve it (after
# writing to it, for example) with FasterCSV.string().
#
# Note that a wrapped String will be positioned at at the beginning (for
# reading). If you want it at the end (for writing), use
# FasterCSV::generate(). If you want any other positioning, pass a preset
# StringIO object instead.
#
# You may set any reading and/or writing preferences in the +options+ Hash.
# Available options are:
#
# <b><tt>:col_sep</tt></b>:: The String placed between each field.
# <b><tt>:row_sep</tt></b>:: The String appended to the end of each
# row. This can be set to the special
# <tt>:auto</tt> setting, which requests
# that FasterCSV automatically discover
# this from the data. Auto-discovery
# reads ahead in the data looking for
# the next <tt>"\r\n"</tt>,
# <tt>"\n"</tt>, or <tt>"\r"</tt>
# sequence. A sequence will be selected
# even if it occurs in a quoted field,
# assuming that you would have the same
# line endings there. If none of those
# sequences is found, +data+ is
# <tt>ARGF</tt>, <tt>STDIN</tt>,
# <tt>STDOUT</tt>, or <tt>STDERR</tt>,
# or the stream is only available for
# output, the default
# <tt>$INPUT_RECORD_SEPARATOR</tt>
# (<tt>$/</tt>) is used. Obviously,
# discovery takes a little time. Set
# manually if speed is important. Also
# note that IO objects should be opened
# in binary mode on Windows if this
# feature will be used as the
# line-ending translation can cause
# problems with resetting the document
# position to where it was before the
# read ahead.
# <b><tt>:quote_char</tt></b>:: The character used to quote fields.
# This has to be a single character
# String. This is useful for
# application that incorrectly use
# <tt>'</tt> as the quote character
# instead of the correct <tt>"</tt>.
# FasterCSV will always consider a
# double sequence this character to be
# an escaped quote.
# <b><tt>:encoding</tt></b>:: The encoding to use when parsing the
# file. Defaults to your <tt>$KDOCE</tt>
# setting. Valid values: <tt>`n’</tt> or
# <tt>`N’</tt> for none, <tt>`e’</tt> or
# <tt>`E’</tt> for EUC, <tt>`s’</tt> or
# <tt>`S’</tt> for SJIS, and
# <tt>`u’</tt> or <tt>`U’</tt> for UTF-8
# (see Regexp.new()).
# <b><tt>:field_size_limit</tt></b>:: This is a maximum size FasterCSV will
# read ahead looking for the closing
# quote for a field. (In truth, it
# reads to the first line ending beyond
# this size.) If a quote cannot be
# found within the limit FasterCSV will
# raise a MalformedCSVError, assuming
# the data is faulty. You can use this
# limit to prevent what are effectively
# DoS attacks on the parser. However,
# this limit can cause a legitimate
# parse to fail and thus is set to
# +nil+, or off, by default.
# <b><tt>:converters</tt></b>:: An Array of names from the Converters
# Hash and/or lambdas that handle custom
# conversion. A single converter
# doesn't have to be in an Array.
# <b><tt>:unconverted_fields</tt></b>:: If set to +true+, an
# unconverted_fields() method will be
# added to all returned rows (Array or
# FasterCSV::Row) that will return the
# fields as they were before convertion.
# Note that <tt>:headers</tt> supplied
# by Array or String were not fields of
# the document and thus will have an
# empty Array attached.
# <b><tt>:headers</tt></b>:: If set to <tt>:first_row</tt> or
# +true+, the initial row of the CSV
# file will be treated as a row of
# headers. If set to an Array, the
# contents will be used as the headers.
# If set to a String, the String is run
# through a call of
# FasterCSV::parse_line() with the same
# <tt>:col_sep</tt>, <tt>:row_sep</tt>,
# and <tt>:quote_char</tt> as this
# instance to produce an Array of
# headers. This setting causes
# FasterCSV.shift() to return rows as
# FasterCSV::Row objects instead of
# Arrays and FasterCSV.read() to return
# FasterCSV::Table objects instead of
# an Array of Arrays.
# <b><tt>:return_headers</tt></b>:: When +false+, header rows are silently
# swallowed. If set to +true+, header
# rows are returned in a FasterCSV::Row
# object with identical headers and
# fields (save that the fields do not go
# through the converters).
# <b><tt>:write_headers</tt></b>:: When +true+ and <tt>:headers</tt> is
# set, a header row will be added to the
# output.
# <b><tt>:header_converters</tt></b>:: Identical in functionality to
# <tt>:converters</tt> save that the
# conversions are only made to header
# rows.
# <b><tt>:skip_blanks</tt></b>:: When set to a +true+ value, FasterCSV
# will skip over any rows with no
# content.
# <b><tt>:force_quotes</tt></b>:: When set to a +true+ value, FasterCSV
# will quote all CSV fields it creates.
#
# See FasterCSV::DEFAULT_OPTIONS for the default settings.
#
# Options cannot be overriden in the instance methods for performance reasons,
# so be sure to set what you want here.
#
def initialize(data, options = Hash.new)
# build the options for this read/write
options = DEFAULT_OPTIONS.merge(options)
# create the IO object we will read from
@io = if data.is_a? String then StringIO.new(data) else data end
init_separators(options)
init_parsers(options)
init_converters(options)
init_headers(options)
unless options.empty?
raise ArgumentError, "Unknown options: #{options.keys.join(', ')}."
end
# track our own lineno since IO gets confused about line-ends is CSV fields
@lineno = 0
end
#
# The line number of the last row read from this file. Fields with nested
# line-end characters will not affect this count.
#
attr_reader :lineno
### IO and StringIO Delegation ###
extend Forwardable
def_delegators :@io, :binmode, :close, :close_read, :close_write, :closed?,
:eof, :eof?, :fcntl, :fileno, :flush, :fsync, :ioctl,
:isatty, :pid, :pos, :reopen, :seek, :stat, :string,
:sync, :sync=, :tell, :to_i, :to_io, :tty?
# Rewinds the underlying IO object and resets FasterCSV's lineno() counter.
def rewind
@headers = nil
@lineno = 0
@io.rewind
end
### End Delegation ###
#
# The primary write method for wrapped Strings and IOs, +row+ (an Array or
# FasterCSV::Row) is converted to CSV and appended to the data source. When a
# FasterCSV::Row is passed, only the row's fields() are appended to the
# output.
#
# The data source must be open for writing.
#
def <<(row)
# make sure headers have been assigned
if header_row? and [Array, String].include? @use_headers.class
parse_headers # won't read data for Array or String
self << @headers if @write_headers
end
# Handle FasterCSV::Row objects and Hashes
row = case row
when self.class::Row then row.fields
when Hash then @headers.map { |header| row[header] }
else row
end
@headers = row if header_row?
@lineno += 1
@io << row.map(&@quote).join(@col_sep) + @row_sep # quote and separate
self # for chaining
end
alias_method :add_row, :<<
alias_method :puts, :<<
#
# :call-seq:
# convert( name )
# convert { |field| ... }
# convert { |field, field_info| ... }
#
# You can use this method to install a FasterCSV::Converters built-in, or
# provide a block that handles a custom conversion.
#
# If you provide a block that takes one argument, it will be passed the field
# and is expected to return the converted value or the field itself. If your
# block takes two arguments, it will also be passed a FieldInfo Struct,
# containing details about the field. Again, the block should return a
# converted field or the field itself.
#
def convert(name = nil, &converter)
add_converter(:converters, self.class::Converters, name, &converter)
end
#
# :call-seq:
# header_convert( name )
# header_convert { |field| ... }
# header_convert { |field, field_info| ... }
#
# Identical to FasterCSV.convert(), but for header rows.
#
# Note that this method must be called before header rows are read to have any
# effect.
#
def header_convert(name = nil, &converter)
add_converter( :header_converters,
self.class::HeaderConverters,
name,
&converter )
end
include Enumerable
#
# Yields each row of the data source in turn.
#
# Support for Enumerable.
#
# The data source must be open for reading.
#
def each
while row = shift
yield row
end
end
#
# Slurps the remaining rows and returns an Array of Arrays.
#
# The data source must be open for reading.
#
def read
rows = to_a
if @use_headers
Table.new(rows)
else
rows
end
end
alias_method :readlines, :read
# Returns +true+ if the next row read will be a header row.
def header_row?
@use_headers and @headers.nil?
end
#
# The primary read method for wrapped Strings and IOs, a single row is pulled
# from the data source, parsed and returned as an Array of fields (if header
# rows are not used) or a FasterCSV::Row (when header rows are used).
#
# The data source must be open for reading.
#
def shift
#########################################################################
### This method is purposefully kept a bit long as simple conditional ###
### checks are faster than numerous (expensive) method calls. ###
#########################################################################
# handle headers not based on document content
if header_row? and @return_headers and
[Array, String].include? @use_headers.class
if @unconverted_fields
return add_unconverted_fields(parse_headers, Array.new)
else
return parse_headers
end
end
# begin with a blank line, so we can always add to it
line = String.new
#
# it can take multiple calls to <tt>@io.gets()</tt> to get a full line,
# because of \r and/or \n characters embedded in quoted fields
#
loop do
# add another read to the line
begin
line += @io.gets(@row_sep)
rescue
return nil
end
# copy the line so we can chop it up in parsing
parse = line.dup
parse.sub!(@parsers[:line_end], "")
#
# I believe a blank line should be an <tt>Array.new</tt>, not
# CSV's <tt>[nil]</tt>
#
if parse.empty?
@lineno += 1
if @skip_blanks
line = ""
next
elsif @unconverted_fields
return add_unconverted_fields(Array.new, Array.new)
elsif @use_headers
return FasterCSV::Row.new(Array.new, Array.new)
else
return Array.new
end
end
# parse the fields with a mix of String#split and regular expressions
csv = Array.new
current_field = String.new
field_quotes = 0
parse.split(@col_sep, -1).each do |match|
if current_field.empty? && match.count(@quote_and_newlines).zero?
csv << (match.empty? ? nil : match)
elsif(current_field.empty? ? match[0] : current_field[0]) == @quote_char[0]
current_field << match
field_quotes += match.count(@quote_char)
if field_quotes % 2 == 0
in_quotes = current_field[@parsers[:quoted_field], 1]
raise MalformedCSVError unless in_quotes
current_field = in_quotes
current_field.gsub!(@quote_char * 2, @quote_char) # unescape contents
csv << current_field
current_field = String.new
field_quotes = 0
else # we found a quoted field that spans multiple lines
current_field << @col_sep
end
elsif match.count("\r\n").zero?
raise MalformedCSVError, "Illegal quoting on line #{lineno + 1}."
else
raise MalformedCSVError, "Unquoted fields do not allow " +
"\\r or \\n (line #{lineno + 1})."
end
end
# if parse is empty?(), we found all the fields on the line...
if field_quotes % 2 == 0
@lineno += 1
# save fields unconverted fields, if needed...
unconverted = csv.dup if @unconverted_fields
# convert fields, if needed...
csv = convert_fields(csv) unless @use_headers or @converters.empty?
# parse out header rows and handle FasterCSV::Row conversions...
csv = parse_headers(csv) if @use_headers
# inject unconverted fields and accessor, if requested...
if @unconverted_fields and not csv.respond_to? :unconverted_fields
add_unconverted_fields(csv, unconverted)
end
# return the results
break csv
end
# if we're not empty?() but at eof?(), a quoted field wasn't closed...
if @io.eof?
raise MalformedCSVError, "Unclosed quoted field on line #{lineno + 1}."
elsif @field_size_limit and current_field.size >= @field_size_limit
raise MalformedCSVError, "Field size exceeded on line #{lineno + 1}."
end
# otherwise, we need to loop and pull some more data to complete the row
end
end
alias_method :gets, :shift
alias_method :readline, :shift
# Returns a simplified description of the key FasterCSV attributes.
def inspect
str = "<##{self.class} io_type:"
# show type of wrapped IO
if @io == $stdout then str << "$stdout"
elsif @io == $stdin then str << "$stdin"
elsif @io == $stderr then str << "$stderr"
else str << @io.class.to_s
end
# show IO.path(), if available
if @io.respond_to?(:path) and (p = @io.path)
str << " io_path:#{p.inspect}"
end
# show other attributes
%w[ lineno col_sep row_sep
quote_char skip_blanks encoding ].each do |attr_name|
if a = instance_variable_get("@#{attr_name}")
str << " #{attr_name}:#{a.inspect}"
end
end
if @use_headers
str << " headers:#{(@headers || true).inspect}"
end
str << ">"
end
private
#
# Stores the indicated separators for later use.
#
# If auto-discovery was requested for <tt>@row_sep</tt>, this method will read
# ahead in the <tt>@io</tt> and try to find one. +ARGF+, +STDIN+, +STDOUT+,
# +STDERR+ and any stream open for output only with a default
# <tt>@row_sep</tt> of <tt>$INPUT_RECORD_SEPARATOR</tt> (<tt>$/</tt>).
#
# This method also establishes the quoting rules used for CSV output.
#
def init_separators(options)
# store the selected separators
@col_sep = options.delete(:col_sep)
@row_sep = options.delete(:row_sep)
@quote_char = options.delete(:quote_char)
@quote_and_newlines = "#{@quote_char}\r\n"
if @quote_char.length != 1
raise ArgumentError, ":quote_char has to be a single character String"
end
# automatically discover row separator when requested
if @row_sep == :auto
if [ARGF, STDIN, STDOUT, STDERR].include?(@io) or
(defined?(Zlib) and @io.class == Zlib::GzipWriter)
@row_sep = $INPUT_RECORD_SEPARATOR
else
begin
saved_pos = @io.pos # remember where we were
while @row_sep == :auto
#
# if we run out of data, it's probably a single line
# (use a sensible default)
#
if @io.eof?
@row_sep = $INPUT_RECORD_SEPARATOR
break
end
# read ahead a bit
sample = @io.read(1024)
sample += @io.read(1) if sample[-1..-1] == "\r" and not @io.eof?
# try to find a standard separator
if sample =~ /\r\n?|\n/
@row_sep = $&
break
end
end
# tricky seek() clone to work around GzipReader's lack of seek()
@io.rewind
# reset back to the remembered position
while saved_pos > 1024 # avoid loading a lot of data into memory
@io.read(1024)
saved_pos -= 1024
end
@io.read(saved_pos) if saved_pos.nonzero?
rescue IOError # stream not opened for reading
@row_sep = $INPUT_RECORD_SEPARATOR
end
end
end
# establish quoting rules
do_quote = lambda do |field|
@quote_char +
String(field).gsub(@quote_char, @quote_char * 2) +
@quote_char
end
@quote = if options.delete(:force_quotes)
do_quote
else
lambda do |field|
if field.nil? # represent +nil+ fields as empty unquoted fields
""
else
field = String(field) # Stringify fields
# represent empty fields as empty quoted fields
if field.empty? or
field.count("\r\n#{@col_sep}#{@quote_char}").nonzero?
do_quote.call(field)
else
field # unquoted field
end
end
end
end
end
# Pre-compiles parsers and stores them by name for access during reads.
def init_parsers(options)
# store the parser behaviors
@skip_blanks = options.delete(:skip_blanks)
@encoding = options.delete(:encoding) # nil will use $KCODE
@field_size_limit = options.delete(:field_size_limit)
# prebuild Regexps for faster parsing
esc_col_sep = Regexp.escape(@col_sep)
esc_row_sep = Regexp.escape(@row_sep)
esc_quote = Regexp.escape(@quote_char)
@parsers = {
:any_field => Regexp.new( "[^#{esc_col_sep}]+",
Regexp::MULTILINE,
@encoding ),
:quoted_field => Regexp.new( "^#{esc_quote}(.*)#{esc_quote}$",
Regexp::MULTILINE,
@encoding ),
# safer than chomp!()
:line_end => Regexp.new("#{esc_row_sep}\\z", nil, @encoding)
}
end
#
# Loads any converters requested during construction.
#
# If +field_name+ is set <tt>:converters</tt> (the default) field converters
# are set. When +field_name+ is <tt>:header_converters</tt> header converters
# are added instead.
#
# The <tt>:unconverted_fields</tt> option is also actived for
# <tt>:converters</tt> calls, if requested.
#
def init_converters(options, field_name = :converters)
if field_name == :converters
@unconverted_fields = options.delete(:unconverted_fields)
end
instance_variable_set("@#{field_name}", Array.new)
# find the correct method to add the coverters
convert = method(field_name.to_s.sub(/ers\Z/, ""))
# load converters
unless options[field_name].nil?
# allow a single converter not wrapped in an Array
unless options[field_name].is_a? Array
options[field_name] = [options[field_name]]
end
# load each converter...
options[field_name].each do |converter|
if converter.is_a? Proc # custom code block
convert.call(&converter)
else # by name
convert.call(converter)
end
end
end
options.delete(field_name)
end
# Stores header row settings and loads header converters, if needed.
def init_headers(options)
@use_headers = options.delete(:headers)
@return_headers = options.delete(:return_headers)
@write_headers = options.delete(:write_headers)
# headers must be delayed until shift(), in case they need a row of content
@headers = nil
init_converters(options, :header_converters)
end
#
# The actual work method for adding converters, used by both
# FasterCSV.convert() and FasterCSV.header_convert().
#
# This method requires the +var_name+ of the instance variable to place the
# converters in, the +const+ Hash to lookup named converters in, and the
# normal parameters of the FasterCSV.convert() and FasterCSV.header_convert()
# methods.
#
def add_converter(var_name, const, name = nil, &converter)
if name.nil? # custom converter
instance_variable_get("@#{var_name}") << converter
else # named converter
combo = const[name]
case combo
when Array # combo converter
combo.each do |converter_name|
add_converter(var_name, const, converter_name)
end
else # individual named converter
instance_variable_get("@#{var_name}") << combo
end
end
end
#
# Processes +fields+ with <tt>@converters</tt>, or <tt>@header_converters</tt>
# if +headers+ is passed as +true+, returning the converted field set. Any
# converter that changes the field into something other than a String halts
# the pipeline of conversion for that field. This is primarily an efficiency
# shortcut.
#
def convert_fields(fields, headers = false)
# see if we are converting headers or fields
converters = headers ? @header_converters : @converters
fields.enum_for(:each_with_index).map do |field, index| # map_with_index
converters.each do |converter|
field = if converter.arity == 1 # straight field converter
converter[field]
else # FieldInfo converter
header = @use_headers && !headers ? @headers[index] : nil
converter[field, FieldInfo.new(index, lineno, header)]
end
break unless field.is_a? String # short-curcuit pipeline for speed
end
field # return final state of each field, converted or original
end
end
#
# This methods is used to turn a finished +row+ into a FasterCSV::Row. Header
# rows are also dealt with here, either by returning a FasterCSV::Row with
# identical headers and fields (save that the fields do not go through the
# converters) or by reading past them to return a field row. Headers are also
# saved in <tt>@headers</tt> for use in future rows.
#
# When +nil+, +row+ is assumed to be a header row not based on an actual row
# of the stream.
#
def parse_headers(row = nil)
if @headers.nil? # header row
@headers = case @use_headers # save headers
# Array of headers
when Array then @use_headers
# CSV header String
when String
self.class.parse_line( @use_headers,
:col_sep => @col_sep,
:row_sep => @row_sep,
:quote_char => @quote_char )
# first row is headers
else row
end
# prepare converted and unconverted copies
row = @headers if row.nil?
@headers = convert_fields(@headers, true)
if @return_headers # return headers
return FasterCSV::Row.new(@headers, row, true)
elsif not [Array, String].include? @use_headers.class # skip to field row
return shift
end
end
FasterCSV::Row.new(@headers, convert_fields(row)) # field row
end
#
# Thiw methods injects an instance variable <tt>unconverted_fields</tt> into
# +row+ and an accessor method for it called unconverted_fields(). The
# variable is set to the contents of +fields+.
#
def add_unconverted_fields(row, fields)
class << row
attr_reader :unconverted_fields
end
row.instance_eval { @unconverted_fields = fields }
row
end
end
# Another name for FasterCSV.
FCSV = FasterCSV
# Another name for FasterCSV::instance().
def FasterCSV(*args, &block)
FasterCSV.instance(*args, &block)
end
# Another name for FCSV::instance().
def FCSV(*args, &block)
FCSV.instance(*args, &block)
end
class Array
# Equivalent to <tt>FasterCSV::generate_line(self, options)</tt>.
def to_csv(options = Hash.new)
FasterCSV.generate_line(self, options)
end
end
class String
# Equivalent to <tt>FasterCSV::parse_line(self, options)</tt>.
def parse_csv(options = Hash.new)
FasterCSV.parse_line(self, options)
end
end
Reference in New Issue View Git Blame Copy Permalink