0001    // The MIT License
0002    //
0003    // Copyright (c) 2015 Gwendal Roué
0004    //
0005    // Permission is hereby granted, free of charge, to any person obtaining a copy
0006    // of this software and associated documentation files (the "Software"), to deal
0007    // in the Software without restriction, including without limitation the rights
0008    // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
0009    // copies of the Software, and to permit persons to whom the Software is
0010    // furnished to do so, subject to the following conditions:
0011    //
0012    // The above copyright notice and this permission notice shall be included in
0013    // all copies or substantial portions of the Software.
0014    //
0015    // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0016    // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0017    // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
0018    // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
0019    // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
0020    // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
0021    // THE SOFTWARE.
0022    
0023    /**
0024    A Context represents a state of the Mustache "context stack".
0025    
0026    The context stack grows and shrinks as the Mustache engine enters and leaves
0027    Mustache sections.
0028    
0029    The top of the context stack is called the "current context". It is the value
0030    rendered by the `{{.}}` tag:
0031    
0032        // Renders "Kitty, Pussy, Melba, "
0033        let template = try! Template(string: "{{#cats}}{{.}}, {{/cats}}")
0034        try! template.render(Box(["cats": ["Kitty", "Pussy", "Melba"]]))
0035    
0036    Key lookup starts with the current context and digs down the stack until if
0037    finds a value:
0038    
0039        // Renders "<child>, <parent>, "
0040        let template = try! Template(string: "{{#children}}<{{name}}>, {{/children}}")
0041        let data = [
0042          "name": "parent",
0043          "children": [
0044              ["name": "child"],
0045              [:]    // a child without a name
0046          ]
0047        ]
0048        try! template.render(Box(data))
0049    
0050    See also:
0051    
0052    - Configuration
0053    - TemplateRepository
0054    - RenderFunction
0055    */
0056    final public class Context
Configuration.swift:100
        baseContext = Context()
Configuration.swift:202
    public var baseContext: Context
Context.swift:75
        self.init(type: .Box(box: box, parent: Context()))
Context.swift:87
        self.init(type: .Root, registeredKeysContext: Context(Box(boxable: [key: box])))
Context.swift:102
    public func extendedContext(box: MustacheBox) -> Context {
Context.swift:103
        return Context(type: .Box(box: box, parent: self), registeredKeysContext: registeredKeysContext)
Context.swift:115
    public func contextWithRegisteredKey(key: String, box: MustacheBox) -> Context {
Context.swift:116
        let registeredKeysContext = (self.registeredKeysContext ?? Context()).extendedContext(Box(boxable: [key: box]))
Context.swift:117
        return Context(type: self.type, registeredKeysContext: registeredKeysContext)
Context.swift:215
        case Box(box: MustacheBox, parent: Context)
Context.swift:216
        case PartialOverride(partialOverride: TemplateASTNode.PartialOverride, parent: Context)
Context.swift:219
    private var registeredKeysContext: Context?
Context.swift:263
    private init(type: ContextType, registeredKeysContext: Context? = nil) {
Context.swift:268
    func extendedContext(partialOverride partialOverride: TemplateASTNode.PartialOverride) -> Context {
Context.swift:269
        return Context(type: .PartialOverride(partialOverride: partialOverride, parent: self), registeredKeysContext: registeredKeysContext)
Context.swift:273
extension Context: CustomDebugStringConvertible {
CoreFunctions.swift:753
    public var context: Context
ExpressionInvocation.swift:26
    func invokeWithContext(context: Context) throws -> MustacheBox {
ExpressionInvocation.swift:30
    private func evaluate(context context: Context, expression: Expression) throws -> MustacheBox {
RenderingEngine.swift:25
    init(templateAST: TemplateAST, context: Context) {
RenderingEngine.swift:41
    private let baseContext: Context
RenderingEngine.swift:44
    private func renderTemplateAST(templateAST: TemplateAST, inContext context: Context) throws {
RenderingEngine.swift:82
    private func renderNode(node: TemplateASTNode, inContext context: Context) throws {
RenderingEngine.swift:127
    private func renderTag(tag: LocatedTag, escapesHTML: Bool, inverted: Bool, expression: Expression, inContext context: Context) throws {
RenderingEngine.swift:209
    private func resolveBlock(block: TemplateASTNode.Block, inContext context: Context) -> TemplateASTNode.Block {
Template.swift:80
    public func render(context: Context) throws -> Rendering {
Template.swift:118
    public var baseContext: Context
Template.swift:207
    init(repository: TemplateRepository, templateAST: TemplateAST, baseContext: Context) {
SectionTag.swift:47
    func render(context: Context) throws -> Rendering {
Tag.swift:147
    func render(context: Context) throws -> Rendering
VariableTag.swift:46
    func render(context: Context) throws -> Rendering {
 {
0057    
0058        // =========================================================================
0059        // MARK: - Creating Contexts
0060    
0061        /**
0062        Builds an empty Context.
0063        */
0064        public convenience init
Configuration.swift:100
        baseContext = Context()
Context.swift:75
        self.init(type: .Box(box: box, parent: Context()))
Context.swift:116
        let registeredKeysContext = (self.registeredKeysContext ?? Context()).extendedContext(Box(boxable: [key: box]))
() {
0065            self.init(type: .Root)
0066        }
0067    
0068        /**
0069        Builds a context that contains the provided box.
0070    
0071        - parameter box: A box.
0072        - returns: A new context that contains *box*.
0073        */
0074        public convenience init
Context.swift:87
        self.init(type: .Root, registeredKeysContext: Context(Box(boxable: [key: box])))
(_ box: MustacheBox) {
0075            self.init(type: .Box(box: box, parent: Context()))
0076        }
0077    
0078        /**
0079        Builds a context with a registered key. Registered keys are looked up first
0080        when evaluating Mustache tags.
0081    
0082        - parameter key: An identifier.
0083        - parameter box: A box.
0084        - returns: A new context with *box* registered for *key*.
0085        */
0086        public convenience init(registeredKey key: String, box: MustacheBox) {
0087            self.init(type: .Root, registeredKeysContext: Context(Box(boxable: [key: box])))
0088        }
0089    
0090    
0091        // =========================================================================
0092        // MARK: - Deriving New Contexts
0093    
0094        /**
0095        Returns a new context with the provided box pushed at the top of the context
0096        stack.
0097    
0098        - parameter box: A box.
0099        - returns: A new context with *box* pushed at the top of the stack.
0100        */
0101        @warn_unused_result(message="Context.extendedContext returns a new Context.")
0102        public func extendedContext
Configuration.swift:241
        baseContext = baseContext.extendedContext(box)
EachFilter.swift:55
                info.context = info.context.extendedContext(Box(boxable: position))
EachFilter.swift:87
                info.context = info.context.extendedContext(Box(boxable: position))
ZipFilter.swift:77
            var context = zippedBoxes.reduce(info.context) { (context, box) in context.extendedContext(box) }
Box.swift:186
                        return try info.tag.render(info.context.extendedContext(Box(boolValue: self)))
Box.swift:243
                        return try info.tag.render(info.context.extendedContext(Box(value: self)))
Box.swift:300
                        return try info.tag.render(info.context.extendedContext(Box(value: self)))
Box.swift:357
                        return try info.tag.render(info.context.extendedContext(Box(value: self)))
Box.swift:938
                    return try info.tag.render(info.context.extendedContext(self.mustacheBoxWithSetValue(value, box: box)))
Box.swift:994
                    return try info.tag.render(info.context.extendedContext(self.mustacheBoxWithArrayValue(value, box: box)))
Context.swift:116
        let registeredKeysContext = (self.registeredKeysContext ?? Context()).extendedContext(Box(boxable: [key: box]))
CoreFunctions.swift:688
            let context = info.context.extendedContext(Box(render: Lambda(lambda)))
MustacheBox.swift:491
                    let context = info.context.extendedContext(self)
Template.swift:58
        let rendering = try render(baseContext.extendedContext(box))
Template.swift:136
        baseContext = baseContext.extendedContext(box)
(box: MustacheBox) -> Context {
0103            return Context(type: .Box(box: box, parent: self), registeredKeysContext: registeredKeysContext)
0104        }
0105    
0106        /**
0107        Returns a new context with the provided box at the top of the context stack.
0108        Registered keys are looked up first when evaluating Mustache tags.
0109    
0110        - parameter key: An identifier.
0111        - parameter box: A box.
0112        - returns: A new context with *box* registered for *key*.
0113        */
0114        @warn_unused_result(message="Context.contextWithRegisteredKey returns a new Context.")
0115        public func contextWithRegisteredKey
Configuration.swift:288
        baseContext = baseContext.contextWithRegisteredKey(key, box: box)
Template.swift:160
        baseContext = baseContext.contextWithRegisteredKey(key, box: box)
(key: String, box: MustacheBox) -> Context {
0116            let registeredKeysContext = (self.registeredKeysContext ?? Context()).extendedContext(Box(boxable: [key: box]))
0117            return Context(type: self.type, registeredKeysContext: registeredKeysContext)
0118        }
0119    
0120    
0121        // =========================================================================
0122        // MARK: - Fetching Values from the Context Stack
0123    
0124        /**
0125        Returns the top box of the context stack, the one that would be rendered by
0126        the `{{.}}` tag.
0127        */
0128        public var topBox
Context.swift:135
            return parent.topBox
ExpressionInvocation.swift:35
            return context.topBox
: MustacheBox {
0129            switch type {
0130            case .Root:
0131                return Box()
0132            case .Box(box: let box, parent: _):
0133                return box
0134            case .PartialOverride(partialOverride: _, parent: let parent):
0135                return parent.topBox
0136            }
0137        }
0138    
0139        /**
0140        Returns the boxed value stored in the context stack for the given key.
0141    
0142        The following search pattern is used:
0143    
0144        1. If the key is "registered", returns the registered box for that key.
0145    
0146        2. Otherwise, searches the context stack for a box that has a non-empty
0147           box for the key (see `InspectFunction`).
0148    
0149        3. If none of the above situations occurs, returns the empty box.
0150    
0151                let data = ["name": "Groucho Marx"]
0152                let context = Context(Box(data))
0153    
0154                // "Groucho Marx"
0155                context.mustacheBoxForKey("name").value
0156    
0157        If you want the value for a full Mustache expression such as `user.name` or
0158        `uppercase(user.name)`, use the `mustacheBoxForExpression` method.
0159    
0160        - parameter key: A key.
0161        - returns: The MustacheBox for *key*.
0162        */
0163        public func mustacheBoxForKey
Context.swift:165
            let box = registeredKeysContext.mustacheBoxForKey(key)
Context.swift:177
                return parent.mustacheBoxForKey(key)
Context.swift:182
            return parent.mustacheBoxForKey(key)
ExpressionInvocation.swift:40
            return context.mustacheBoxForKey(identifier)
(key: String) -> MustacheBox {
0164            if let registeredKeysContext = registeredKeysContext {
0165                let box = registeredKeysContext.mustacheBoxForKey(key)
0166                if !box.isEmpty {
0167                    return box
0168                }
0169            }
0170    
0171            switch type {
0172            case .Root:
0173                return Box()
0174            case .Box(box: let box, parent: let parent):
0175                let innerBox = box.mustacheBoxForKey(key)
0176                if innerBox.isEmpty {
0177                    return parent.mustacheBoxForKey(key)
0178                } else {
0179                    return innerBox
0180                }
0181            case .PartialOverride(partialOverride: _, parent: let parent):
0182                return parent.mustacheBoxForKey(key)
0183            }
0184        }
0185    
0186        /**
0187        Evaluates a Mustache expression such as `name`, or `uppercase(user.name)`.
0188    
0189            let data = ["person": ["name": "Albert Einstein"]]
0190            let context = Context(Box(data))
0191    
0192            // "Albert Einstein"
0193            try! context.mustacheBoxForExpression("person.name").value
0194    
0195        - parameter string: The expression string.
0196        - parameter error:  If there is a problem parsing or evaluating the
0197                            expression, throws an error that describes the problem.
0198    
0199        - returns: The value of the expression.
0200        */
0201        public func mustacheBoxForExpression(string: String) throws -> MustacheBox {
0202            let parser = ExpressionParser()
0203            var empty = false
0204            let expression = try parser.parse(string, empty: &empty)
0205            let invocation = ExpressionInvocation(expression: expression)
0206            return try invocation.invokeWithContext(self)
0207        }
0208    
0209    
0210        // =========================================================================
0211        // MARK: - Not public
0212    
0213        private enum ContextType
Context.swift:220
    private let type: ContextType
Context.swift:263
    private init(type: ContextType, registeredKeysContext: Context? = nil) {
 {
0214            case Root
Context.swift:65
        self.init(type: .Root)
Context.swift:87
        self.init(type: .Root, registeredKeysContext: Context(Box(boxable: [key: box])))
Context.swift:130
        case .Root:
Context.swift:172
        case .Root:
Context.swift:224
        case .Root:
Context.swift:239
        case .Root:
Context.swift:254
        case .Root:
Context.swift:277
        case .Root:

0215            case Box
Context.swift:75
        self.init(type: .Box(box: box, parent: Context()))
Context.swift:103
        return Context(type: .Box(box: box, parent: self), registeredKeysContext: registeredKeysContext)
Context.swift:132
        case .Box(box: let box, parent: _):
Context.swift:174
        case .Box(box: let box, parent: let parent):
Context.swift:226
        case .Box(box: let box, parent: let parent):
Context.swift:241
        case .Box(box: let box, parent: let parent):
Context.swift:256
        case .Box(box: _, parent: let parent):
Context.swift:279
        case .Box(box: let box, parent: let parent):
(box: MustacheBox, parent: Context)
0216            case PartialOverride
Context.swift:134
        case .PartialOverride(partialOverride: _, parent: let parent):
Context.swift:181
        case .PartialOverride(partialOverride: _, parent: let parent):
Context.swift:232
        case .PartialOverride(partialOverride: _, parent: let parent):
Context.swift:247
        case .PartialOverride(partialOverride: _, parent: let parent):
Context.swift:258
        case .PartialOverride(partialOverride: let partialOverride, parent: let parent):
Context.swift:269
        return Context(type: .PartialOverride(partialOverride: partialOverride, parent: self), registeredKeysContext: registeredKeysContext)
Context.swift:281
        case .PartialOverride(partialOverride: _, parent: let parent):
(partialOverride: TemplateASTNode.PartialOverride, parent: Context)
0217        }
0218    
0219        private var registeredKeysContext
Context.swift:103
        return Context(type: .Box(box: box, parent: self), registeredKeysContext: registeredKeysContext)
Context.swift:116
        let registeredKeysContext = (self.registeredKeysContext ?? Context()).extendedContext(Box(boxable: [key: box]))
Context.swift:164
        if let registeredKeysContext = registeredKeysContext {
Context.swift:265
        self.registeredKeysContext = registeredKeysContext
Context.swift:269
        return Context(type: .PartialOverride(partialOverride: partialOverride, parent: self), registeredKeysContext: registeredKeysContext)
: Context?
0220        private let type
Context.swift:117
        return Context(type: self.type, registeredKeysContext: registeredKeysContext)
Context.swift:129
        switch type {
Context.swift:171
        switch type {
Context.swift:223
        switch type {
Context.swift:238
        switch type {
Context.swift:253
        switch type {
Context.swift:264
        self.type = type
Context.swift:276
        switch type {
: ContextType
0221    
0222        var willRenderStack
Context.swift:228
                return [willRender] + parent.willRenderStack
Context.swift:230
                return parent.willRenderStack
Context.swift:233
            return parent.willRenderStack
RenderingEngine.swift:150
        for willRender in context.willRenderStack {
: [WillRenderFunction] {
0223            switch type {
0224            case .Root:
0225                return []
0226            case .Box(box: let box, parent: let parent):
0227                if let willRender = box.willRender {
0228                    return [willRender] + parent.willRenderStack
0229                } else {
0230                    return parent.willRenderStack
0231                }
0232            case .PartialOverride(partialOverride: _, parent: let parent):
0233                return parent.willRenderStack
0234            }
0235        }
0236    
0237        var didRenderStack
Context.swift:243
                return parent.didRenderStack + [didRender]
Context.swift:245
                return parent.didRenderStack
Context.swift:248
            return parent.didRenderStack
RenderingEngine.swift:180
            for didRender in context.didRenderStack {
RenderingEngine.swift:201
        for didRender in context.didRenderStack {
: [DidRenderFunction] {
0238            switch type {
0239            case .Root:
0240                return []
0241            case .Box(box: let box, parent: let parent):
0242                if let didRender = box.didRender {
0243                    return parent.didRenderStack + [didRender]
0244                } else {
0245                    return parent.didRenderStack
0246                }
0247            case .PartialOverride(partialOverride: _, parent: let parent):
0248                return parent.didRenderStack
0249            }
0250        }
0251    
0252        var partialOverrideStack
Context.swift:257
            return parent.partialOverrideStack
Context.swift:259
            return [partialOverride] + parent.partialOverrideStack
RenderingEngine.swift:217
        return context.partialOverrideStack.reduce(block) { (block, partialOverride) in
: [TemplateASTNode.PartialOverride] {
0253            switch type {
0254            case .Root:
0255                return []
0256            case .Box(box: _, parent: let parent):
0257                return parent.partialOverrideStack
0258            case .PartialOverride(partialOverride: let partialOverride, parent: let parent):
0259                return [partialOverride] + parent.partialOverrideStack
0260            }
0261        }
0262    
0263        private init
Context.swift:65
        self.init(type: .Root)
Context.swift:75
        self.init(type: .Box(box: box, parent: Context()))
Context.swift:87
        self.init(type: .Root, registeredKeysContext: Context(Box(boxable: [key: box])))
Context.swift:103
        return Context(type: .Box(box: box, parent: self), registeredKeysContext: registeredKeysContext)
Context.swift:117
        return Context(type: self.type, registeredKeysContext: registeredKeysContext)
Context.swift:269
        return Context(type: .PartialOverride(partialOverride: partialOverride, parent: self), registeredKeysContext: registeredKeysContext)
(type: ContextType, registeredKeysContext: Context? = nil) {
0264            self.type = type
0265            self.registeredKeysContext = registeredKeysContext
0266        }
0267    
0268        func extendedContext
RenderingEngine.swift:95
            let context = context.extendedContext(partialOverride: partialOverride)
(partialOverride partialOverride: TemplateASTNode.PartialOverride) -> Context {
0269            return Context(type: .PartialOverride(partialOverride: partialOverride, parent: self), registeredKeysContext: registeredKeysContext)
0270        }
0271    }
0272    
0273    extension Context: CustomDebugStringConvertible {
0274        /// A textual representation of `self`, suitable for debugging.
0275        public var debugDescription
Context.swift:280
            return "Context.Box(\(box)):\(parent.debugDescription)"
Context.swift:282
            return "Context.PartialOverride:\(parent.debugDescription)"
: String {
0276            switch type {
0277            case .Root:
0278                return "Context.Root"
0279            case .Box(box: let box, parent: let parent):
0280                return "Context.Box(\(box)):\(parent.debugDescription)"
0281            case .PartialOverride(partialOverride: _, parent: let parent):
0282                return "Context.PartialOverride:\(parent.debugDescription)"
0283            }
0284        }
0285    }