Add an include tag

README.md

@@ -128,6 +128,22 @@ A for loop allows you to iterate over an array found by variable lookup.
 {% endif %}
 ```
 
+#### include
+
+You can include another template using the `include` tag.
+
+```html+django
+{% include "comment.html" %}
+```
+
+The `include` tag requires a TemplateLoader to be found inside your context with the paths, or bundles used to lookup the template.
+
+```swift
+let context = Context(dictionary: [
+  "loader": TemplateLoader(bundle:[NSBundle.mainBundle()])
+])
+```
+
 #### Building custom tags
 
 You can build a custom template tag. There are a couple of APIs to allow

Stencil.xcodeproj/project.pbxproj

@@ -10,6 +10,8 @@
 		27CE0ADE1A50BEC3004A105B /* TemplateLoader.swift in Sources */ = {isa = PBXBuildFile; fileRef = 27CE0ADD1A50BEC3004A105B /* TemplateLoader.swift */; };
 		27CE0AE01A50BF05004A105B /* TemplateLoaderTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 27CE0ADF1A50BF05004A105B /* TemplateLoaderTests.swift */; };
 		27CE0AFA1A50C963004A105B /* test.html in Resources */ = {isa = PBXBuildFile; fileRef = 27CE0AF91A50C963004A105B /* test.html */; };
+		27CE0B011A50CBD1004A105B /* Include.swift in Sources */ = {isa = PBXBuildFile; fileRef = 27CE0B001A50CBD1004A105B /* Include.swift */; };
+		27CE0B041A50CBEA004A105B /* IncludeTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 27CE0B031A50CBEA004A105B /* IncludeTests.swift */; };
 		27E2138D1A4CD5F50073E063 /* UniversalFramework_Base.xcconfig in Resources */ = {isa = PBXBuildFile; fileRef = 27E2138A1A4CD5F50073E063 /* UniversalFramework_Base.xcconfig */; };
 		27E2138E1A4CD5F50073E063 /* UniversalFramework_Framework.xcconfig in Resources */ = {isa = PBXBuildFile; fileRef = 27E2138B1A4CD5F50073E063 /* UniversalFramework_Framework.xcconfig */; };
 		27E2138F1A4CD5F50073E063 /* UniversalFramework_Test.xcconfig in Resources */ = {isa = PBXBuildFile; fileRef = 27E2138C1A4CD5F50073E063 /* UniversalFramework_Test.xcconfig */; };
@@ -75,6 +77,8 @@
 		27CE0ADF1A50BF05004A105B /* TemplateLoaderTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TemplateLoaderTests.swift; sourceTree = "<group>"; };
 		27CE0AE11A50BFAF004A105B /* PathKit.xcodeproj */ = {isa = PBXFileReference; lastKnownFileType = "wrapper.pb-project"; name = PathKit.xcodeproj; path = PathKit/PathKit.xcodeproj; sourceTree = "<group>"; };
 		27CE0AF91A50C963004A105B /* test.html */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.html; path = test.html; sourceTree = "<group>"; };
+		27CE0B001A50CBD1004A105B /* Include.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Include.swift; sourceTree = "<group>"; };
+		27CE0B031A50CBEA004A105B /* IncludeTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = IncludeTests.swift; sourceTree = "<group>"; };
 		27E2138A1A4CD5F50073E063 /* UniversalFramework_Base.xcconfig */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.xcconfig; path = UniversalFramework_Base.xcconfig; sourceTree = "<group>"; };
 		27E2138B1A4CD5F50073E063 /* UniversalFramework_Framework.xcconfig */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.xcconfig; path = UniversalFramework_Framework.xcconfig; sourceTree = "<group>"; };
 		27E2138C1A4CD5F50073E063 /* UniversalFramework_Test.xcconfig */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.xcconfig; path = UniversalFramework_Test.xcconfig; sourceTree = "<group>"; };
@@ -128,6 +132,22 @@
 			name = Products;
 			sourceTree = "<group>";
 		};
+		27CE0AFF1A50CBBF004A105B /* TemplateLoader */ = {
+			isa = PBXGroup;
+			children = (
+				27CE0B001A50CBD1004A105B /* Include.swift */,
+			);
+			path = TemplateLoader;
+			sourceTree = "<group>";
+		};
+		27CE0B021A50CBEA004A105B /* TemplateLoader */ = {
+			isa = PBXGroup;
+			children = (
+				27CE0B031A50CBEA004A105B /* IncludeTests.swift */,
+			);
+			path = TemplateLoader;
+			sourceTree = "<group>";
+		};
 		27E213891A4CD5F50073E063 /* Configurations */ = {
 			isa = PBXGroup;
 			children = (
@@ -171,6 +191,7 @@
 				27CE0ADD1A50BEC3004A105B /* TemplateLoader.swift */,
 				7725B3CE19F94214002CF74B /* Tokenizer.swift */,
 				7725B3CC19F92B61002CF74B /* Variable.swift */,
+				27CE0AFF1A50CBBF004A105B /* TemplateLoader */,
 				77FAAE5519F91E480029DC5E /* Supporting Files */,
 			);
 			path = Stencil;
@@ -195,6 +216,7 @@
 				77EB082819FA85F2001870F1 /* LexerTests.swift */,
 				77EB082619F96E9C001870F1 /* TemplateTests.swift */,
 				27CE0ADF1A50BF05004A105B /* TemplateLoaderTests.swift */,
+				27CE0B021A50CBEA004A105B /* TemplateLoader */,
 				27CE0AF91A50C963004A105B /* test.html */,
 				77FAAE6219F91E480029DC5E /* Supporting Files */,
 			);
@@ -345,6 +367,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				27CE0B011A50CBD1004A105B /* Include.swift in Sources */,
 				77FAAE6F19F920750029DC5E /* Context.swift in Sources */,
 				77EB082B19FA8600001870F1 /* Lexer.swift in Sources */,
 				7725B3CF19F94214002CF74B /* Tokenizer.swift in Sources */,
@@ -367,6 +390,7 @@
 				7725B3D919F94A61002CF74B /* ParserTests.swift in Sources */,
 				77EB082719F96E9C001870F1 /* TemplateTests.swift in Sources */,
 				7725B3CB19F92B4F002CF74B /* VariableTests.swift in Sources */,
+				27CE0B041A50CBEA004A105B /* IncludeTests.swift in Sources */,
 				77EB082919FA85F2001870F1 /* LexerTests.swift in Sources */,
 				77FAAE7119F9208C0029DC5E /* ContextTests.swift in Sources */,
 			);

Stencil/Parser.swift

@@ -36,6 +36,7 @@ public class TokenParser {
         registerTag("if", IfNode.parse)
         registerTag("ifnot", IfNode.parse_ifnot)
         registerTag("now", NowNode.parse)
+        registerTag("include", IncludeNode.parse)
     }
 
     /// Registers a new template tag

Stencil/TemplateLoader.swift

@@ -11,7 +11,7 @@ import PathKit
 
 // A class for loading a template from disk
 public class TemplateLoader {
-    let paths:[Path]
+    public let paths:[Path]
 
     public init(paths:[Path]) {
         self.paths = paths

Stencil/TemplateLoader/Include.swift

@@ -0,0 +1,44 @@
+import Foundation
+import PathKit
+
+extension String : Error {
+    public var description:String {
+        return self
+    }
+}
+
+public class IncludeNode : Node {
+    public let templateName:String
+
+    public class func parse(parser:TokenParser, token:Token) -> TokenParser.Result {
+        let bits = token.contents.componentsSeparatedByString("\"")
+
+        if bits.count != 3 {
+            return .Error(error:NodeError(token: token, message: "Tag takes one argument, the template file to be included"))
+        }
+
+        return .Success(node:IncludeNode(templateName: bits[1]))
+    }
+
+    public init(templateName:String) {
+        self.templateName = templateName
+    }
+
+    public func render(context: Context) -> Result {
+        if let loader =  context["loader"] as? TemplateLoader {
+            if let template = loader.loadTemplate(templateName) {
+                return template.render(context)
+            }
+
+            let paths:String = join(", ", loader.paths.map { path in
+                return path.description
+            })
+            let error = "Template '\(templateName)' not found in \(paths)"
+            return .Error(error)
+        }
+
+        let error = "Template loader not in context"
+        return .Error(error)
+    }
+}
+

StencilTests/TemplateLoader/IncludeTests.swift

@@ -0,0 +1,75 @@
+import Foundation
+import XCTest
+import Stencil
+import PathKit
+
+class IncludeTests: NodeTests {
+
+    var loader:TemplateLoader!
+
+    override func setUp() {
+        super.setUp()
+
+        let path = (Path(__FILE__) + Path("../..")).absolute()
+        loader = TemplateLoader(paths: [path])
+    }
+
+    // MARK: Parsing
+
+    func testParseMissingTemplate() {
+        let tokens = [ Token.Block(value: "include") ]
+        let parser = TokenParser(tokens: tokens)
+
+        assertFailure(parser.parse(), "include: Tag takes one argument, the template file to be included")
+    }
+
+    func testParse() {
+        let tokens = [ Token.Block(value: "include \"test.html\"") ]
+        let parser = TokenParser(tokens: tokens)
+
+        assertSuccess(parser.parse()) { nodes in
+            let node = nodes.first! as IncludeNode
+            XCTAssertEqual(nodes.count, 1)
+            XCTAssertEqual(node.templateName, "test.html")
+        }
+    }
+
+    // MARK: Render
+
+    func testRenderWithoutLoader() {
+        let node = IncludeNode(templateName: "test.html")
+        let result = node.render(Context())
+
+        switch result {
+        case .Success(let string):
+            XCTAssert(false, "Unexpected error")
+        case .Error(let error):
+            XCTAssertEqual("\(error)", "Template loader not in context")
+        }
+    }
+
+    func testRenderWithoutTemplateNamed() {
+        let node = IncludeNode(templateName: "unknown.html")
+        let result = node.render(Context(dictionary:["loader":loader]))
+
+        switch result {
+        case .Success(let string):
+            XCTAssert(false, "Unexpected error")
+        case .Error(let error):
+            XCTAssertTrue("\(error)".hasPrefix("Template 'unknown.html' not found"))
+        }
+    }
+
+    func testRender() {
+        let node = IncludeNode(templateName: "test.html")
+        let result = node.render(Context(dictionary:["loader":loader, "target": "World"]))
+
+        switch result {
+        case .Success(let string):
+            XCTAssertEqual(string, "Hello World!")
+        case .Error(let error):
+            XCTAssert(false, "Unexpected error: \(error)")
+        }
+    }
+
+}

StencilTests/test.html

@@ -1 +1 @@
-Hello {{ target }}.
+Hello {{ target }}!