| library mustache.lambda_context; |
| |
| import 'package:mustache/mustache.dart' as m; |
| |
| import 'node.dart'; |
| import 'parser.dart' as parser; |
| import 'renderer.dart'; |
| import 'template_exception.dart'; |
| |
| /// Passed as an argument to a mustache lambda function. |
| class LambdaContext implements m.LambdaContext { |
| |
| final Node _node; |
| final Renderer _renderer; |
| final bool _isSection; |
| bool _closed = false; |
| |
| LambdaContext(this._node, this._renderer, {bool isSection: true}) |
| : _isSection = isSection; |
| |
| void close() { |
| _closed = true; |
| } |
| |
| void _checkClosed() { |
| if (_closed) throw _error('LambdaContext accessed outside of callback.'); |
| } |
| |
| TemplateException _error(String msg) { |
| return new TemplateException(msg, _renderer.templateName, _renderer.source, |
| _node.start); |
| } |
| |
| /// Render the current section tag in the current context and return the |
| /// result as a string. |
| String renderString({Object value}) { |
| _checkClosed(); |
| if (_node is! SectionNode) _error( |
| 'LambdaContext.renderString() can only be called on section tags.'); |
| var sink = new StringBuffer(); |
| _renderSubtree(sink, value); |
| return sink.toString(); |
| } |
| |
| void _renderSubtree(StringSink sink, Object value) { |
| var renderer = new Renderer.subtree(_renderer, sink); |
| SectionNode section = _node; |
| if (value != null) renderer.push(value); |
| renderer.render(section.children); |
| } |
| |
| void render({Object value}) { |
| _checkClosed(); |
| if (_node is! SectionNode) _error( |
| 'LambdaContext.render() can only be called on section tags.'); |
| _renderSubtree(_renderer.sink, value); |
| } |
| |
| void write(Object object) { |
| _checkClosed(); |
| _renderer.write(object); |
| } |
| |
| /// Get the unevaluated template source for the current section tag. |
| String get source { |
| _checkClosed(); |
| |
| if (_node is! SectionNode) return ''; |
| |
| SectionNode node = _node; |
| |
| var nodes = node.children; |
| |
| if (nodes.isEmpty) return ''; |
| |
| if (nodes.length == 1 && nodes.first is TextNode) return nodes.first.text; |
| |
| return _renderer.source.substring(node.contentStart, node.contentEnd); |
| } |
| |
| /// Evaluate the string as a mustache template using the current context. |
| String renderSource(String source, {Object value}) { |
| _checkClosed(); |
| var sink = new StringBuffer(); |
| |
| // Lambdas used for sections should parse with the current delimiters. |
| var delimiters = '{{ }}'; |
| if (_node is SectionNode) { |
| SectionNode node = _node; |
| delimiters = node.delimiters; |
| } |
| |
| var nodes = parser.parse(source, |
| _renderer.lenient, |
| _renderer.templateName, |
| delimiters); |
| |
| var renderer = new Renderer.lambda( |
| _renderer, |
| source, |
| _renderer.indent, |
| sink, |
| delimiters); |
| |
| if (value != null) renderer.push(value); |
| renderer.render(nodes); |
| |
| return sink.toString(); |
| } |
| |
| /// Lookup the value of a variable in the current context. |
| Object lookup(String variableName) { |
| _checkClosed(); |
| return _renderer.resolveValue(variableName); |
| } |
| |
| } |