Class: Csvdb::Table

Inherits:
Object
  • Object
show all
Defined in:
lib/csvdb/table.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}) ⇒ Table

Returns a new instance of Table.



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# File 'lib/csvdb/table.rb', line 9

def initialize(opts = {})

  if opts[:file]
    @file = opts[:file]
    table = CSV.read(@file)
    @cols = table[0].map.with_index {|head,idx| [head.to_sym,idx] }.to_h
    table.delete_at(0)
  elsif opts[:ary]
    table = opts[:ary]
    @cols = opts[:cols]
  else
    raise ParseError, 'No table or file to parse.'
  end

  @cols.each do |col, val|
    add_attr(col, val)
  end

  @table = []
  table.each_with_index do |row, idx|
    @table[idx] = Row.new(row, self, idx)
  end

end

Instance Attribute Details

#cols ⇒ Object

Returns the value of attribute cols.



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# File 'lib/csvdb/table.rb', line 7

def cols
  @cols
end

#table ⇒ Object

Returns the value of attribute table.



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# File 'lib/csvdb/table.rb', line 7

def table
  @table
end

Instance Method Details

#all ⇒ Object 



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# File 'lib/csvdb/table.rb', line 43

def all
  @table
end

#count ⇒ Object 



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# File 'lib/csvdb/table.rb', line 47

def count
  @table.count
end

#create(attrs) ⇒ Object 



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# File 'lib/csvdb/table.rb', line 51

def create(attrs)
  new_row = []
  attrs.each do |att, new_val|
    new_row[@cols[att]] = new_val
  end
  @table << Row.new(new_row, self, @table.length)
end

#find(idx = nil) ⇒ Object 



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# File 'lib/csvdb/table.rb', line 63

def find(idx = nil)
  if block_given?
    @table.select { |row| yield(row) }.first
  elsif idx
    @table[idx]
  else
    raise ArgumentError, 'Must pass either an index or a block.'
  end
end

#pluck(header) ⇒ Object

Raises:



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# File 'lib/csvdb/table.rb', line 73

def pluck(header)
  col = @cols[header.to_sym] ; vals = []
  raise SearchError, "Column #{header} does not exist." unless col
  @table.each do |row|
    vals << row[col]
  end
  vals
end

#pretty ⇒ Object 



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# File 'lib/csvdb/table.rb', line 82

def pretty
  table = Terminal::Table.new headings: @cols.keys, rows: @table
  puts table
end

#where ⇒ Object 



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# File 'lib/csvdb/table.rb', line 59

def where
  Table.new(ary: @table.select { |row| yield(row) }, cols: self.cols)
end

#write(file = @file) ⇒ Object 



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# File 'lib/csvdb/table.rb', line 34

def write(file = @file)
  CSV.open(file, 'wb') do |csv|
    csv << @cols.keys
    @table.each do |row|
      csv << row
    end
  end
end