DefaultTemplateSystem.java

package com.google.sitebricks;

import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.Singleton;
import com.google.sitebricks.compiler.TemplateCompiler;

import java.util.Map;
import java.util.Set;

@Singleton
public class DefaultTemplateSystem implements TemplateSystem {
  private static final String DEFAULT = "flat";
  private final Map<String, Class<? extends TemplateCompiler>> templateCompilers;
  private final Injector injector;

  @Inject
  public DefaultTemplateSystem(Map<String, Class<? extends TemplateCompiler>> templateCompilers, Injector injector) {
    this.templateCompilers = templateCompilers;
    this.injector = injector;
  }

  @Override
  public TemplateCompiler compilerFor(String templateName) {
    String extension = templateName.substring(templateName.lastIndexOf(".") + 1);
    Class<? extends TemplateCompiler> type = templateCompilers.get(extension);
    if (type == null)
      type = templateCompilers.get(DEFAULT);
    return injector.getInstance(type);
  }

  @Override
  public String[] getTemplateExtensions() {
    Set<String> keys = templateCompilers.keySet();

    if (keys.isEmpty()) {
      return new String[0];
    }

    String[] extensions = new String[keys.size()];

    int i = 0;
    for (String ext : keys) {
      extensions[i++] = "%s." + ext;
    }

    return extensions;
  }
}