FindCalleesNotInFileVisitor.java

/*
 * Copyright 2008 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.template.soy.shared.internal;

import com.google.common.base.Preconditions;
import com.google.template.soy.soytree.AbstractSoyNodeVisitor;
import com.google.template.soy.soytree.CallBasicNode;
import com.google.template.soy.soytree.SoyFileNode;
import com.google.template.soy.soytree.SoyNode;
import com.google.template.soy.soytree.SoyNode.ParentSoyNode;
import com.google.template.soy.soytree.TemplateNode;
import java.util.LinkedHashSet;
import java.util.Set;

/**
 * Visitor for finding the templates called in a file that are not defined in the file.
 *
 * <p>Important: Only deals with basic callees (not delegates). Calls to delegates are not
 * applicable here because we cannot tell at compile time which delegate will be called (if any).
 *
 * <p>Precondition: All template and callee names should be full names (i.e. you must execute {@code
 * SetFullCalleeNamesVisitor} before executing this visitor).
 *
 * <p>{@link #exec} should be called on a {@code SoyFileNode}. The returned set will be the full
 * names of all templates called by the templates in this file that that not in this file. In other
 * words, if T is the set of templates in this file and U is the set of templates not in this file,
 * then the returned set consists of the full names of all templates in U called by any template in
 * T.
 *
 */
public final class FindCalleesNotInFileVisitor extends AbstractSoyNodeVisitor<Set<CallBasicNode>> {

  /** The names of templates defined in this file. */
  private Set<String> templatesInFile;

  /** The call nodes of templates not defined in this file (the result). */
  private Set<CallBasicNode> calleesNotInFile;

  @Override
  public Set<CallBasicNode> exec(SoyNode node) {
    Preconditions.checkArgument(node instanceof SoyFileNode);
    visit(node);
    return calleesNotInFile;
  }

  // -----------------------------------------------------------------------------------------------
  // Implementations for specific nodes.

  @Override
  protected void visitSoyFileNode(SoyFileNode node) {
    templatesInFile = new LinkedHashSet<>();
    for (TemplateNode template : node.getChildren()) {
      templatesInFile.add(template.getTemplateName());
    }

    calleesNotInFile = new LinkedHashSet<>();
    visitChildren(node);
  }

  @Override
  protected void visitCallBasicNode(CallBasicNode node) {
    String calleeName = node.getCalleeName();
    if (!templatesInFile.contains(calleeName)) {
      calleesNotInFile.add(node);
    }
    visitChildren(node);
  }

  // -----------------------------------------------------------------------------------------------
  // Fallback implementation.

  @Override
  protected void visitSoyNode(SoyNode node) {
    if (node instanceof ParentSoyNode<?>) {
      visitChildren((ParentSoyNode<?>) node);
    }
  }
}