es-kumagai / escsvparser

A type-safe CSV parser module for swift 2.0.

ESCSVParser

ESCSVParser is a type-safe CSV parser module for Swift 2.

You can write data type which use as a CSV row by simple code, and create an array of the data type from a CSV file easily.

This module is highly inspired by Himotoki which is a type-safe JSON decoding library !

Usage

1. Define a data type

struct StatisticalData : CSVRowRepresentable {
	
	var country:String
	var capital:String
	var population:Int
	var favolite:Bool?
	
	static func fromRawLine(line: RawLine) throws -> StatisticalData {
		
		return try line.make(StatisticalData.init)(from: 1, 2, 3, 4)
	}
}

1. Create a type which conforms to CSVRowRepresentable protocol.
2. Implement properties to the type. If the type of the property is an optional type, the property will assign nil if it meets certain condition (e.g. empty string to Int?).
3. Implement an initializer if necessary. Normally use the default initializer.
4. Implement fromRawLine method. In this method, you must create an instance of self type and return it. At this time, you can use raw csv line data which having line argument. By using make method in line, you can pick up raw columns by column index and convert to values of native type.

2. Create a CSV data from a CSV file.

let csv = try! CSV<StatisticalData>(path: path)

1. Use CSV type which specified RowType by generic parameter (e.g. CSV).
2. Call the initializer with CSV file path, you will get the data by an array of RowType.

3. Use the CSV data.

let raw1:StatisticalData = csv[1]

XCTAssertEqual(raw1.country, "Japan")
XCTAssertEqual(raw1.population, 127767944)

1. you can retrieve a row data in the CSV data by index which starting with 1.

Supported CSV format

• A csv file encoding by UTF-8.
• Columns are written in a natural text or a quoted text by double quotations.

Country,Capital,Population,favolite
Japan,Tokyo,127767944,yes
"U.S.A",Washington,"300007997",no

Supported CSV Column type

You can assign types that conforms to RawColumnConvertible protocol to properties in a type for CSV row.

It is already conforms that types Int, Int8, Int16, Int32, Int64, UInt, UInt8, UInt16, UInt32, UInt64, String, Double, Float, Float80, Bool and Optional<T> which these type have.

You can make any CSV Column type using RawColumnConvertible .

Custom type support

If you want to other types, you will create a type which conforms to RawColumnConvertible protocol. A type which conforms to this protocol and implement fromRawColumn method can convert from a raw column value.

extension Bool : RawColumnConvertible {
	
	public static func fromRawColumn(rawColumn: RawColumn) throws -> Bool {
		
		switch rawColumn.value.lowercaseString {
			
		case "true", "yes", "1":
			return true
			
		case "false", "no", "0":
			return false
			
		default:
			throw FromRawColumnError()
		}
	}
}

It needs to throw FromRawColumnError if the type cannot convert from rawColumn value.

Optional support

If you want to treat the type in Optional<T>, the type will also need to conforms to RawColumnNullable protocol. A type which conforms to this protocol and implement isRawColumnNull method, you can specify the conditions which the value of the type will be convert to nil.

extension Bool : RawColumnNullable {

	static func isRawColumnNull(rawColumn:RawColumn) -> Bool {
	
		return rawColumn.isEmpty
	}
}

Requirements

• Swift 2.1 (Xcode 7.1)
• iOS 8.0 or later / OS X 10.9 or later

Installation

Add following line to your Podfile and run pod install.

pod 'ESCSVParser', :git => 'https://github.com/EZ-NET/ESCSVParser.git'

License

ESCSVParser is released under the MIT License.

escsvparser's Issues

Xcode 7 beta 5 でカラムに Optional 型の値を扱えない。

カラムとして String? のような RawColumnConvertible な要素を持つ Optional を指定したとき、RawColumn からの変換に失敗します。

原因は extension Optional where T : RawColumnConvertible に実装した fromRawColumn が呼ばれずに、常に extension RawColumnConvertibleOptional で実装した fromRawColumn が呼び出されるためです。このため nil が返却されて変換に失敗したことになります。