1/*
2 * Copyright (C) 2010 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.clearsilver.jsilver.interpreter;
18
19import com.google.clearsilver.jsilver.autoescape.EscapeMode;
20import com.google.clearsilver.jsilver.resourceloader.ResourceLoader;
21import com.google.clearsilver.jsilver.syntax.TemplateSyntaxTree;
22
23import java.util.ArrayList;
24import java.util.List;
25
26/**
27 * Wraps a template factory with a series of optimization steps. Any null optimization steps are
28 * ignored.
29 */
30public class OptimizingTemplateFactory implements TemplateFactory {
31  private final TemplateFactory wrapped;
32  private final List<OptimizerProvider> optimizers;
33
34  /**
35   * Creates a factory from the given optimization steps that wraps another TemplateFactory.
36   *
37   * @param wrapped the template factory instance to be wrapped.
38   * @param optimizers the optimizers to apply (null optimizations are ignored).
39   */
40  public OptimizingTemplateFactory(TemplateFactory wrapped, OptimizerProvider... optimizers) {
41    this.wrapped = wrapped;
42    // Ignore null providers during construction.
43    this.optimizers = new ArrayList<OptimizerProvider>();
44    for (OptimizerProvider optimizer : optimizers) {
45      if (optimizer != null) {
46        this.optimizers.add(optimizer);
47      }
48    }
49  }
50
51  private void optimize(TemplateSyntaxTree ast) {
52    for (OptimizerProvider optimizer : optimizers) {
53      ast.apply(optimizer.getOptimizer());
54    }
55  }
56
57  @Override
58  public TemplateSyntaxTree createTemp(String content, EscapeMode escapeMode) {
59    TemplateSyntaxTree result = wrapped.createTemp(content, escapeMode);
60    optimize(result);
61    return result;
62  }
63
64  @Override
65  public TemplateSyntaxTree find(String templateName, ResourceLoader resourceLoader,
66      EscapeMode escapeMode) {
67    TemplateSyntaxTree result = wrapped.find(templateName, resourceLoader, escapeMode);
68    optimize(result);
69    return result;
70  }
71}
72