cesare/csv_generator

CsvGenerator

Just a CSV generator :)
It ensures string fields quoted.

What is the difference from standard CSV library?

Standard CSV also can quote values with force_quotes option, like this:

CSV.open(filename, 'w', force_quotes: true) do |csv|
  csv << ['0123', 987]
end

This example above quotes ALL values (including the numeric value 987).
It generates

"0123","987"

Note that the numeric value 987 is also quoted. In most cases, this behavior is sufficient.

However, sometimes it would be useful if you can distinguish string values and numeric values with quotation, in following manner:

• if a value is quoted, it is a string
• if not, it is a number

CsvGenerator follows these rules.
You can generate:

"0123",987

As you see, numeric value 987 is not quoted.

Some CSV-readable application might interpret "0123" as a string, 987 as a number. Is such a case, CsvGenerator will be useful.

Installation

Add this line to your application's Gemfile:

gem 'csv_generator'

And then execute:

$ bundle

Or install it yourself as:

$ gem install csv_generator

Usage

Basic usage is something like this:

CsvGenerator.open('example.csv') do |csv|
  csv << ['0123', 456, 'this is a string']
end
# writes to example.csv:
# "0123",456,"this is a string"

If you have multiple rows,

rows = [
  ['0123', 456, 'this is a string'],
  ['1234', 987, 'this is the second row']
]

CsvGenerator.open('example.csv') do |csv|
  rows.each do |row|
    csv << row
  end
end
# writes to example.csv:
# "0123",456,"this is a string"
# "1234",987,"this is the second row"

Or using CsvGenerator#generate,

rows = [
  ['0123', 456, 'this is a string'],
  ['1234', 987, 'this is the second row']
]

CsvGenerator.open('example.csv').generate(rows)
# writes to example.csv:
# "0123",456,"this is a string"
# "1234",987,"this is the second row"

Data source of a row does not have to be an array. If you have objects (such as ActiveRecord instances),

class User
  attr_reader :name, :score
end

users = [
  User.new(name: 'test1', score: 123),
  User.new(name: 'test2', socre: 987)
]

CsvGenerator.open('example.csv') do |csv|
  csv.generate(users) do |user|
    [user.name, user.score]
  end
end
# writes to example.csv:
# "test1",123
# "test2",987

If you need a string instead of a file, use StringIO like this:

io = StringIO.new
CsvGenerator.new(io) do |csv|
  csv << ['test', 123]
end

io.string # => "test",123

Contributing

1. Fork it ( https://github.com/cesare/csv_generator/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request