package io.dropwizard.views.mustache;
import com.github.mustachejava.Mustache;
import com.github.mustachejava.MustacheException;
import com.github.mustachejava.MustacheFactory;
import com.google.common.base.Charsets;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.util.concurrent.UncheckedExecutionException;
import io.dropwizard.views.View;
import io.dropwizard.views.ViewRenderer;
import javax.ws.rs.WebApplicationException;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.nio.charset.Charset;
import java.util.Locale;
import java.util.concurrent.ExecutionException;
/**
* A {@link ViewRenderer} which renders Mustache ({@code .mustache}) templates.
*/
public class MustacheViewRenderer implements ViewRenderer {
private final LoadingCache<Class<? extends View>, MustacheFactory> factories;
public MustacheViewRenderer() {
this.factories = CacheBuilder.newBuilder()
.build(new CacheLoader<Class<? extends View>, MustacheFactory>() {
@Override
public MustacheFactory load(Class<? extends View> key) throws Exception {
return new PerClassMustacheFactory(key);
}
});
}
@Override
public boolean isRenderable(View view) {
return view.getTemplateName().endsWith(".mustache");
}
@Override
public void render(View view, Locale locale, OutputStream output) throws IOException, WebApplicationException {
try {
final Mustache template = factories.get(view.getClass())
.compile(view.getTemplateName());
final Charset charset = view.getCharset().or(Charsets.UTF_8);
try (OutputStreamWriter writer = new OutputStreamWriter(output, charset)) {
template.execute(writer, view);
}
} catch (ExecutionException | UncheckedExecutionException | MustacheException ignored) {
throw new FileNotFoundException("Template " + view.getTemplateName() + " not found.");
}
}
}