114 lines
3.1 KiB
Swift
114 lines
3.1 KiB
Swift
class BlockContext {
|
|
class var contextKey: String { return "block_context" }
|
|
|
|
var blocks: [String:BlockNode]
|
|
|
|
init(blocks: [String:BlockNode]) {
|
|
self.blocks = blocks
|
|
}
|
|
|
|
func pop(_ blockName: String) -> BlockNode? {
|
|
return blocks.removeValue(forKey: blockName)
|
|
}
|
|
}
|
|
|
|
|
|
extension Collection {
|
|
func any(_ closure: (Iterator.Element) -> Bool) -> Iterator.Element? {
|
|
for element in self {
|
|
if closure(element) {
|
|
return element
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
}
|
|
|
|
|
|
class ExtendsNode : NodeType {
|
|
let templateName: Variable
|
|
let blocks: [String:BlockNode]
|
|
|
|
class func parse(_ parser: TokenParser, token: Token) throws -> NodeType {
|
|
let bits = token.components()
|
|
|
|
guard bits.count == 2 else {
|
|
throw TemplateSyntaxError("'extends' takes one argument, the template file to be extended")
|
|
}
|
|
|
|
let parsedNodes = try parser.parse()
|
|
guard (parsedNodes.any { $0 is ExtendsNode }) == nil else {
|
|
throw TemplateSyntaxError("'extends' cannot appear more than once in the same template")
|
|
}
|
|
|
|
let blockNodes = parsedNodes.filter { node in node is BlockNode }
|
|
|
|
let nodes = blockNodes.reduce([String:BlockNode]()) { (accumulator, node:NodeType) -> [String:BlockNode] in
|
|
let node = (node as! BlockNode)
|
|
var dict = accumulator
|
|
dict[node.name] = node
|
|
return dict
|
|
}
|
|
|
|
return ExtendsNode(templateName: Variable(bits[1]), blocks: nodes)
|
|
}
|
|
|
|
init(templateName: Variable, blocks: [String: BlockNode]) {
|
|
self.templateName = templateName
|
|
self.blocks = blocks
|
|
}
|
|
|
|
func render(_ context: Context) throws -> String {
|
|
guard let loader = context["loader"] as? TemplateLoader else {
|
|
throw TemplateSyntaxError("Template loader not in context")
|
|
}
|
|
|
|
guard let templateName = try self.templateName.resolve(context) as? String else {
|
|
throw TemplateSyntaxError("'\(self.templateName)' could not be resolved as a string")
|
|
}
|
|
|
|
guard let template = loader.loadTemplate(templateName) else {
|
|
let paths:String = loader.paths.map { $0.description }.joined(separator: ", ")
|
|
throw TemplateSyntaxError("'\(templateName)' template not found in \(paths)")
|
|
}
|
|
|
|
let blockContext = BlockContext(blocks: blocks)
|
|
return try context.push(dictionary: [BlockContext.contextKey: blockContext]) {
|
|
return try template.render(context)
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
class BlockNode : NodeType {
|
|
let name: String
|
|
let nodes: [NodeType]
|
|
|
|
class func parse(_ parser: TokenParser, token: Token) throws -> NodeType {
|
|
let bits = token.components()
|
|
|
|
guard bits.count == 2 else {
|
|
throw TemplateSyntaxError("'block' tag takes one argument, the template file to be included")
|
|
}
|
|
|
|
let blockName = bits[1]
|
|
let nodes = try parser.parse(until(["endblock"]))
|
|
_ = parser.nextToken()
|
|
return BlockNode(name:blockName, nodes:nodes)
|
|
}
|
|
|
|
init(name: String, nodes: [NodeType]) {
|
|
self.name = name
|
|
self.nodes = nodes
|
|
}
|
|
|
|
func render(_ context: Context) throws -> String {
|
|
if let blockContext = context[BlockContext.contextKey] as? BlockContext, let node = blockContext.pop(name) {
|
|
return try node.render(context)
|
|
}
|
|
|
|
return try renderNodes(nodes, context)
|
|
}
|
|
}
|