| /* |
| * Copyright 2009 Google Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| * use this file except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| package com.google.gwt.uibinder.parsers; |
| |
| import com.google.gwt.core.ext.UnableToCompleteException; |
| import com.google.gwt.uibinder.parsers.FieldReferenceConverter.Delegate; |
| import com.google.gwt.uibinder.parsers.FieldReferenceConverter.IllegalFieldReferenceException; |
| import com.google.gwt.uibinder.rebind.UiBinderWriter; |
| |
| /** |
| * Fall through attribute parser. Accepts a field reference or nothing. |
| */ |
| public class StrictAttributeParser implements AttributeParser { |
| |
| /** |
| * Package protected for testing |
| */ |
| static class FieldReferenceDelegate implements Delegate { |
| boolean sawReference = false; |
| |
| public String handleFragment(String fragment) |
| throws IllegalFieldReferenceException { |
| if (fragment.length() > 0) { |
| throw new IllegalFieldReferenceException(); |
| } |
| return fragment; |
| } |
| |
| public String handleReference(String reference) |
| throws IllegalFieldReferenceException { |
| assertOnly(); |
| sawReference = true; |
| return reference; |
| } |
| |
| private void assertOnly() { |
| if (sawReference) { |
| throw new IllegalFieldReferenceException(); |
| } |
| } |
| } |
| |
| /** |
| * If the value holds a single field reference "{like.this}", converts it to a |
| * Java Expression. |
| * <p> |
| * In any other case (e.g. more than one field reference), an |
| * UnableToCompleteException is thrown. |
| */ |
| public String parse(String value, UiBinderWriter writer) |
| throws UnableToCompleteException { |
| |
| try { |
| return new FieldReferenceConverter(new FieldReferenceDelegate()).convert(value); |
| } catch (IllegalFieldReferenceException e) { |
| writer.die("Bad field reference: \"%s\"", value); |
| return null; // Unreachable |
| } |
| } |
| } |