Class: Csv_lazy

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/csv_lazy.rb

Overview

A simple library for parsing CSV-files through IO’s. Solves corrupt file formats automatically like when files contains several spaces after a column and more.

Instance Method Summary collapse

Constructor Details

#initialize(args = {}, &blk) ⇒ Csv_lazy

Examples

File.open("csvfile.csv", "r") do |fp|
  Csv_lazy.new(:io => fp, :quote_char => '"', :col_sep => ";", :row_sep => "\n", :encode => "utf-8") do |row_array|
    puts "Row: #{row_array}"
  end
end



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# File 'lib/csv_lazy.rb', line 16

def initialize(args = {}, &blk)
  @args = {
    :quote_char => '"',
    :row_sep => "\n",
    :col_sep => ";",
    :headers => false,
    :buffer_length => 4096
  }.merge(args)
  
  @io = @args[:io]
  @eof = false
  @buffer = ""
  @debug = @args[:debug]
  @encode = @args[:encode]
  @mutex = Mutex.new
  @buffer_length = @args[:buffer_length]
  @escape_char = "\\"
  @escaped_quote = "#{@escape_char}#{@args[:quote_char]}"
  @escaped_quote_double = "#{@escape_char}#{@escape_char}#{@args[:quote_char]}"
  
  #@debug = true
  
  accepted = [:encode, :quote_char, :row_sep, :col_sep, :io, :debug, :headers, :buffer_length]
  @args.each do |key, val|
    if accepted.index(key) == nil
      raise "Unknown argument: '#{key}'."
    end
  end
  
  raise "No ':quote_char' was given." if @args[:quote_char].to_s.strip.empty?
  raise "No ':col_sep' was given." if @args[:col_sep].to_s.empty?
  raise "No ':row_sep' was given." if @args[:row_sep].to_s.empty?
  raise "No ':io' was given." if !@args[:io]
  
  @regex_begin_quote_char = /\A\s*#{Regexp.escape(@args[:quote_char])}/
  
  @regex_row_end = /\A\s*?#{Regexp.escape(@args[:row_sep])}/
  @regex_colsep_next = /\A#{Regexp.escape(@args[:col_sep])}/
  
  @regex_read_until_quote_char = /\A(.*?)#{Regexp.escape(@args[:quote_char])}/
  @regex_read_until_col_sep = /\A(.*?)#{Regexp.escape(@args[:col_sep])}/
  @regex_read_until_row_sep = /\A(.+?)#{Regexp.escape(@args[:row_sep])}/
  @regex_read_until_end = /\A(.+?)\Z/
  
  if @args[:headers]
    headers = []
    read_row.each do |key|
      headers << key.to_sym
    end
    
    @headers = headers
  end
  
  self.each(&blk) if blk
end

Instance Method Details

#each ⇒ Object

Yields each row as an array.



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# File 'lib/csv_lazy.rb', line 73

def each
  if block_given?
    @mutex.synchronize do
      while row = read_row
        yield(row)
      end
    end
  else
    Enumerable.new do |yielder|
      @mutex.synchronize do
        while row = read_row
          yielder << row
        end
      end
    end
  end
end

#read_row ⇒ Object

Returns the next row.



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# File 'lib/csv_lazy.rb', line 92

def read_row
  @row = []
  while !@eof or !@buffer.empty?
    break if !read_next_col
  end
  
  row = @row
  @row = nil
  
  puts "csv_lazy: Row: #{row}\n\n" if @debug
  
  if row.empty?
    return false
  else
    if @headers
      ret = {}
      row.length.times do |count|
        ret[@headers[count]] = row[count]
      end
      
      return ret
    else
      return row
    end
  end
end