Merge pull request #11 from g-Off/t-filter

Implemented t filter

Author: katbutler

Sources/Liquid/Context.swift

@@ -47,17 +47,19 @@ public final class Context {
 	private var registers: [String: Any] = [:]
 
 	public let filters: [String: FilterFunc]
+	public let translations: [String: String]?
 	public let tags: [String: TagBuilder]
 	public let environment: Environment
 	public let encoder: Encoder
 	public let fileSystem: FileSystem
 
-	init(fileSystem: FileSystem, values: [String: Value] = [:], environment: Environment = Environment(), tags: [String: TagBuilder], filters: [String: FilterFunc] = [:], encoder: Encoder) {
+	init(fileSystem: FileSystem, values: [String: Value] = [:], environment: Environment = Environment(), tags: [String: TagBuilder], filters: [String: FilterFunc] = [:], translations: [String: String]? = nil, encoder: Encoder) {
 		self.fileSystem = fileSystem
 		self.scopes = [Scope(values: values)]
 		self.environment = environment
 		self.tags = tags
 		self.filters = filters
+		self.translations = translations
 		self.encoder = encoder
 	}
 

Sources/Liquid/Filter+Standard.swift

@@ -54,6 +54,7 @@ enum Filters {
 		template.registerFilter(name: "sort", filter: sortFilter)
 		template.registerFilter(name: "sort_natural", filter: sortNaturalFilter)
 		template.registerFilter(name: "date", filter: dateFilter)
+		template.registerFilter(name: "t", filter: tFilter)
 	}
 
 	static func appendFilter(value: Value, args: [Value], kwargs: [String: Value], context: FilterContext) throws -> Value {
@@ -512,6 +513,25 @@ enum Filters {
 		}
 		return Value(formatter.string(from: date))
 	}
+
+	static func tFilter(value: Value, args: [Value], kwargs: [String: Value], context: FilterContext) throws -> Value {
+		guard let translations = context.translations else {
+			throw RuntimeError.reason("No translations dictionary available")
+		}
+		
+		guard let val = translations[value.toString()] else {
+			throw RuntimeError.reason("Invalid translation key")
+		}
+		
+		if kwargs.isEmpty && args.isEmpty {
+			return Value(val)
+		}
+		if !kwargs.isEmpty {
+			return Value(val.replaceWithValues(kwargs))
+		}
+		
+		throw RuntimeError.unimplemented
+	}
 
 	private static func convertValueToDate(_ value: Value, context: FilterContext) -> Date? {
 		if value.isInteger {
@@ -530,3 +550,28 @@ enum Filters {
 		return context.encoder.dateEncodingStrategry.date(from: string)
 	}
 }
+
+private extension String {
+	func replaceWithValues(_ values: [String: Value]) -> String {
+		let scanner = Scanner(string: self)
+		scanner.charactersToBeSkipped = CharacterSet.newlines
+		
+		var result: String = ""
+		var temp: NSString?
+		
+		while !scanner.isAtEnd {
+			scanner.scanUpTo("%{", into: &temp)
+			scanner.scanCharacters(from: CharacterSet.init(charactersIn: "%{"), into: nil)
+			
+			result = "\(result)\(temp ?? "")"
+			
+			scanner.scanUpTo("}", into: &temp)
+			scanner.scanCharacters(from: CharacterSet.init(charactersIn: "}"), into: nil)
+			
+			let resultValue = values[String(temp ?? "")]?.toString() ?? ""
+			result = "\(result)\(resultValue)"
+		}
+		
+		return result
+	}
+}

Sources/Liquid/FilterContext.swift

@@ -9,12 +9,14 @@ import Foundation
 
 public struct FilterContext {
 	public let encoder: Encoder
+	public let translations: [String: String]?
 
 	init(context: Context) {
-		self.init(encoder: context.encoder)
+		self.init(encoder: context.encoder, translations: context.translations)
 	}
 
-	init(encoder: Encoder) {
+	init(encoder: Encoder, translations: [String: String]? = nil) {
 		self.encoder = encoder
+		self.translations = translations
 	}
 }

Sources/Liquid/Template.swift

@@ -22,7 +22,9 @@ public final class Template {
 
 	private let fileSystem: FileSystem
 
-	public convenience init(sourceURL: URL, encoder: Encoder = Encoder(), environment: Environment = Environment()) throws {
+	private let translations: [String: String]?
+	
+	public convenience init(sourceURL: URL, encoder: Encoder = Encoder(), environment: Environment = Environment(), translations: [String: String]? = nil) throws {
 		let source = try String(contentsOf: sourceURL)
 		let fileSystem = LocalFileSystem(baseURL: sourceURL.deletingLastPathComponent())
 		self.init(source: source, fileSystem: fileSystem, encoder: encoder, environment: environment)
@@ -43,13 +45,15 @@ public final class Template {
 		self.environment = context.environment
 		self.fileSystem = context.fileSystem
 		self.filters = context.filters
+		self.translations = context.translations
 		self.tags = context.tags
 	}
 
-	private init(source: String, fileSystem: FileSystem, encoder: Encoder, environment: Environment) {
+	private init(source: String, fileSystem: FileSystem, encoder: Encoder, environment: Environment, translations: [String: String]? = nil) {
 		self.source = source
 		self.fileSystem = fileSystem
 		self.environment = environment
+		self.translations = translations
 		self.encoder = encoder
 
 		tags["assign"] = Assign.init
@@ -88,7 +92,7 @@ public final class Template {
 	}
 
 	public func render(values: [String: Value] = [:]) throws -> String {
-		let context = Context(fileSystem: fileSystem, values: values, environment: environment, tags: tags, filters: filters, encoder: encoder)
+		let context = Context(fileSystem: fileSystem, values: values, environment: environment, tags: tags, filters: filters, translations: translations, encoder: encoder)
 		return try render(context: context)
 	}
 

Tests/LiquidTests/FilterTests.swift

@@ -271,6 +271,21 @@ final class FilterTests: XCTestCase {
 		XCTAssertEqual(try Filters.dateFilter(value: Value("1152098955"), args: [Value("%m/%d/%Y")], kwargs: [:], context: FilterContext(encoder: encoder)), Value("07/05/2006"))
 	}
 
+	func testTranslate() {
+		var encoder = Encoder()
+		encoder.locale = Locale(identifier: "en_US")
+		
+		let sampleTranslationDict: [String: String] = [
+			"x.files.main.characters": "%{argA} and %{argB}",
+			"x.files.title": "The X-Files",
+		]
+		
+		let filterContext = FilterContext(encoder: encoder, translations: sampleTranslationDict)
+		
+		XCTAssertEqual(try Filters.tFilter(value: Value("x.files.title"), args: [], kwargs: [:], context: filterContext), Value("The X-Files"))
+		XCTAssertEqual(try Filters.tFilter(value: Value("x.files.main.characters"), args: [], kwargs: ["argA": Value("Fox Mulder"), "argB": Value("Dana Scully")], context: filterContext), Value("Fox Mulder and Dana Scully"))
+	}
+	
 	func testFilterArgs() {
 		let echoFilter: FilterFunc = { (value, args, kwargs, encoder) -> Value in
 			let strArgs = args.map { "\($0)" }.sorted()