UiActions.java example

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gerrit-master
// Copyright (C) 2013 The Android Open Source Project
//
// 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.gerrit.server.extensions.webui;

import com.google.common.base.Predicate;
import com.google.common.collect.FluentIterable;
import com.google.gerrit.common.Nullable;
import com.google.gerrit.extensions.api.access.GlobalOrPluginPermission;
import com.google.gerrit.extensions.registration.DynamicMap;
import com.google.gerrit.extensions.restapi.RestCollection;
import com.google.gerrit.extensions.restapi.RestResource;
import com.google.gerrit.extensions.restapi.RestView;
import com.google.gerrit.extensions.webui.PrivateInternals_UiActionDescription;
import com.google.gerrit.extensions.webui.UiAction;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.permissions.GlobalPermission;
import com.google.gerrit.server.permissions.PermissionBackend;
import com.google.gerrit.server.permissions.PermissionBackendException;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;
import java.util.Objects;
import java.util.Set;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Singleton
public class UiActions {
  private static final Logger log = LoggerFactory.getLogger(UiActions.class);

  public static Predicate<UiAction.Description> enabled() {
    return UiAction.Description::isEnabled;
  }

  private final PermissionBackend permissionBackend;
  private final Provider<CurrentUser> userProvider;

  @Inject
  UiActions(PermissionBackend permissionBackend, Provider<CurrentUser> userProvider) {
    this.permissionBackend = permissionBackend;
    this.userProvider = userProvider;
  }

  public <R extends RestResource> FluentIterable<UiAction.Description> from(
      RestCollection<?, R> collection, R resource) {
    return from(collection.views(), resource);
  }

  public <R extends RestResource> FluentIterable<UiAction.Description> from(
      DynamicMap<RestView<R>> views, R resource) {
    return FluentIterable.from(views)
        .transform((e) -> describe(e, resource))
        .filter(Objects::nonNull);
  }

  @Nullable
  private <R extends RestResource> UiAction.Description describe(
      DynamicMap.Entry<RestView<R>> e, R resource) {
    int d = e.getExportName().indexOf('.');
    if (d < 0) {
      return null;
    }

    RestView<R> view;
    try {
      view = e.getProvider().get();
    } catch (RuntimeException err) {
      log.error(
          String.format("error creating view %s.%s", e.getPluginName(), e.getExportName()), err);
      return null;
    }

    if (!(view instanceof UiAction)) {
      return null;
    }

    try {
      Set<GlobalOrPluginPermission> need =
          GlobalPermission.fromAnnotation(e.getPluginName(), view.getClass());
      if (!need.isEmpty() && permissionBackend.user(userProvider).test(need).isEmpty()) {
        // A permission is required, but test returned no candidates.
        return null;
      }
    } catch (PermissionBackendException err) {
      log.error(
          String.format("exception testing view %s.%s", e.getPluginName(), e.getExportName()), err);
      return null;
    }

    UiAction.Description dsc = ((UiAction<R>) view).getDescription(resource);
    if (dsc == null || !dsc.isVisible()) {
      return null;
    }

    String name = e.getExportName().substring(d + 1);
    PrivateInternals_UiActionDescription.setMethod(dsc, e.getExportName().substring(0, d));
    PrivateInternals_UiActionDescription.setId(
        dsc, "gerrit".equals(e.getPluginName()) ? name : e.getPluginName() + '~' + name);
    return dsc;
  }
}