/*
* Copyright 2012 Objectos, Fábrica de Software LTDA.
*
* 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 br.com.objectos.way.ui.form;
import static com.google.common.collect.Lists.newArrayList;
import static com.google.common.collect.Maps.newHashMap;
import java.lang.annotation.Annotation;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.validation.ConstraintViolation;
import br.com.objectos.way.relational.Crud;
import br.com.objectos.way.ui.BaseUrl;
import br.com.objectos.way.ui.Context;
import br.com.objectos.way.ui.form.FormResponse.Error;
import br.com.objectos.way.ui.json.EntityJson;
import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.inject.Provider;
import com.google.sitebricks.client.transport.Json;
import com.google.sitebricks.headless.Reply;
import com.google.sitebricks.headless.Request;
/**
* @author marcio.endo@objectos.com.br (Marcio Endo)
*/
class EntityFormImpl<T extends EntityJson> implements EntityForm<T> {
private final Class<T> type;
private final BaseUrl baseUrl;
private final Crud crud;
private final Provider<Request> requests;
private final Validator javaxValidator;
private MethodFilter<T> filter = new AlwaysMethodFilter<T>();
private ActionListener<T> listener = new EmptyActionListener<T>();
private ContextDecorator<T> decorator;
private Redirect<T> redirect;
private AbstractValidator<T> validator;
private final Map<Method, Action<T>> actionMap;
private final Map<Method, Redirect<T>> redirectMap = newHashMap();
private final Map<Method, AbstractValidator<T>> validatorMap = newHashMap();
public EntityFormImpl(Class<T> type,
BaseUrl baseUrl,
Crud crud,
Provider<Request> requests,
Validator validator) {
this.type = type;
this.baseUrl = baseUrl;
this.crud = crud;
this.requests = requests;
this.javaxValidator = validator;
actionMap = newHashMap();
actionMap.put(Method.POST, new DefaultCreateAction());
actionMap.put(Method.PUT, new DefaultUpdateAction());
actionMap.put(Method.DELETE, new DefaultDeleteAction());
}
@Override
public EntityForm<T> withMethodFilter(MethodFilter<T> filter) {
this.filter = filter;
return this;
}
@Override
public EntityForm<T> withActionListener(ActionListener<T> listener) {
this.listener = listener;
return this;
}
@Override
public EntityForm<T> withContextDecorator(ContextDecorator<T> decorator) {
Preconditions.checkArgument(redirect == null,
"You cannot use a decorator and a redirect at the same time");
this.decorator = decorator;
return this;
}
@Override
public EntityForm<T> withRedirect(Redirect<T> redirect) {
Preconditions.checkArgument(decorator == null,
"You cannot use a decorator and a redirect at the same time");
this.redirect = redirect;
return this;
}
@Override
public EntityForm<T> withValidator(AbstractValidator<T> validator) {
this.validator = validator;
return this;
}
@Override
public OnMethod<T> on(final Class<? extends Annotation> methodAnnotation) {
Preconditions.checkArgument(decorator == null,
"You cannot use a decorator and a redirect at the same time");
return new OnMethod<T>() {
@Override
public EntityForm<T> execute(Action<T> action) {
Method method = Method.parse(methodAnnotation);
actionMap.put(method, action);
return EntityFormImpl.this;
}
@Override
public EntityForm<T> redirect(Redirect<T> redirect) {
Method method = Method.parse(methodAnnotation);
redirectMap.put(method, redirect);
return EntityFormImpl.this;
}
@Override
public EntityForm<T> validate(AbstractValidator<T> validator) {
Method method = Method.parse(methodAnnotation);
validatorMap.put(method, validator);
return EntityFormImpl.this;
}
};
}
@Override
public Reply<?> reply() {
Request request = requests.get();
T pojo = request.read(type).as(Json.class);
Method method = Method.parse(request);
List<Error> errors = newArrayList();
List<Error> javaxErrors = javaxValidation(pojo);
errors.addAll(javaxErrors);
if (validator != null) {
List<Error> validatorErrors = formValidation(validator, pojo);
errors.addAll(validatorErrors);
}
if (validatorMap.containsKey(method)) {
AbstractValidator<T> methodValidator = validatorMap.get(method);
List<Error> validatorErrors = formValidation(methodValidator, pojo);
errors.addAll(validatorErrors);
}
if (errors.isEmpty()) {
try {
tryToExecute(method, pojo);
} catch (Throwable e) {
errors.add(Errors.toForm(e));
}
}
Context context = null;
String redirectUrl = null;
if (errors.isEmpty()) {
if (decorator != null) {
context = Context.of();
decorator.decorate(context, pojo);
}
if (redirect != null) {
redirectUrl = redirect.getUrl(baseUrl, pojo);
}
if (redirectMap.containsKey(method)) {
Redirect<T> methodRedirect = redirectMap.get(method);
redirectUrl = methodRedirect.getUrl(baseUrl, pojo);
}
}
FormResponse json = FormJson.of(context, errors, redirectUrl);
return Reply.with(json).as(Json.class);
}
private List<Error> javaxValidation(T pojo) {
Set<ConstraintViolation<T>> violations = javaxValidator.validate(pojo);
Iterable<FormResponse.Error> iter = Iterables.transform(violations, new ToError());
return ImmutableList.copyOf(iter);
}
private List<Error> formValidation(AbstractValidator<T> validator, T pojo) {
validator.validate(pojo);
return validator.getErrors();
}
private void tryToExecute(Method method, T pojo) {
switch (method) {
case POST:
if (filter.shouldCreate(pojo)) {
pojo = actionMap.get(method).execute(pojo);
listener.onCreate(pojo);
}
break;
case PUT:
if (filter.shouldUpdate(pojo)) {
pojo = actionMap.get(method).execute(pojo);
listener.onUpdate(pojo);
}
break;
case DELETE:
if (filter.shouldDelete(pojo)) {
pojo = actionMap.get(method).execute(pojo);
listener.onDelete(pojo);
}
break;
}
}
private static class AlwaysMethodFilter<T extends EntityJson> extends AbstractMethodFilter<T> {}
private class DefaultCreateAction extends AbstractAction<T> {
@Override
public T execute(T pojo) {
crud.create(pojo);
return pojo;
}
}
private class DefaultUpdateAction extends AbstractAction<T> {
@Override
public T execute(T pojo) {
crud.update(pojo);
return pojo;
}
}
private class DefaultDeleteAction extends AbstractAction<T> {
@Override
public T execute(T pojo) {
crud.delete(pojo);
return pojo;
}
}
private class ToError implements Function<ConstraintViolation<T>, FormResponse.Error> {
@Override
public FormResponse.Error apply(ConstraintViolation<T> input) {
return Errors.toField(input);
}
}
private enum Method {
POST,
PUT,
DELETE;
public static Method parse(Request request) {
String method = request.method();
return Method.valueOf(method.toUpperCase());
}
public static Method parse(Class<? extends Annotation> annotation) {
String method = annotation.getSimpleName();
return Method.valueOf(method.toUpperCase());
}
}
}