Apply scheduled updates to preplanned map area

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Sample viewer app

Apply scheduled updates to a downloaded preplanned map area.

screenshot

Use case

With scheduled updates, the author can update the features within the preplanned areas on the service once, and multiple end-users can request these updates to bring their local copies up to date with the most recent state. Importantly, any number of end-users can download the same set of cached updates, which means that this workflow is extremely scalable for large operations where you need to minimize load on the server.

This workflow can be used by survey workers operating in remote areas where network connectivity is not available. The workers could download mobile map packages to their individual devices and perform their work normally. Once they regain internet connectivity, the mobile map packages can be updated to show any new features that have been added to the online service.

How to use the sample

Start the app. It will display an offline map, check for available updates, and show update availability and size. Select 'Apply Scheduled Updates' to apply the updates to the local offline map and show the results.

How it works

Create an OfflineMapSyncTask with your offline map.
If desired, get OfflineMapUpdatesInfo from the task to check for update availability or update size.
Get a set of default OfflineMapSyncParameters for the task.
Set the parameters to download all available updates.
Use the parameters to create an OfflineMapSyncJob.
Start the job and get the results once it completes successfully.
Check if the mobile map package needs to be reopened, and do so if necessary.
Finally, display your offline map to see the changes.

Relevant API

MobileMapPackage
OfflineMapSyncJob
OfflineMapSyncParameters
OfflineMapSyncResult
OfflineMapSyncTask
OfflineMapUpdatesInfo

Offline data

Read more about how to set up the sample's offline data here.

Link	Local Location
Canyonlands MMPK	`<userhome>`/ArcGIS/Runtime/Data/mmpk/canyonlands.zip

About the data

The data in this sample shows the roads and trails in the Canyonlands National Park, Utah. Data by U.S. National Parks Service. No claim to original U.S. Government works.

Additional information

Note: preplanned areas using the Scheduled Updates workflow are read-only. For preplanned areas that can be edited on the end-user device, see the Download preplanned map area sample. For more information about offline workflows, see Offline maps, scenes, and data in the ArcGIS Developers guide.

Sample Code

ApplyScheduledMapUpdates.cpp

ApplyScheduledMapUpdates.h

ApplyScheduledMapUpdates.qml

Use dark colors for code blocksCopy
// [WriteFile Name=ApplyScheduledMapUpdates, Category=Maps]
// [Legal]
// Copyright 2019 Esri.

// 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.
// [Legal]

#ifdef PCH_BUILD
#include "pch.hpp"
#endif // PCH_BUILD

#include "ApplyScheduledMapUpdates.h"

#include "Map.h"
#include "MapQuickView.h"
#include "MobileMapPackage.h"
#include "OfflineMapSyncTask.h"
#include "OfflineMapUpdatesInfo.h"
#include "OfflineMapSyncParameters.h"
#include "OfflineMapSyncJob.h"

#include <QDir>
#include <QFile>
#include <QFileInfo>
#include <QtCore/qglobal.h>

#ifdef Q_OS_IOS
#include <QStandardPaths>
#endif // Q_OS_IOS

using namespace Esri::ArcGISRuntime;

// helper method to get cross platform data path
namespace
{
QString defaultDataPath()
{
  QString dataPath;

#ifdef Q_OS_ANDROID
  dataPath = "/sdcard";
#elif defined Q_OS_IOS
  dataPath = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation);
#else
  dataPath = QDir::homePath();
#endif

  return dataPath + "/ArcGIS/Runtime/Data/mmpk";
}

// sample MMPK location
const QString sampleMmpk { "canyonlands" };

// helper to copy directory from source to destination
bool copyDir(const QString &srcPath, const QString &dstPath)
{
  const QDir parentDstDir(QFileInfo(dstPath).path());
  if (!parentDstDir.mkdir(QFileInfo(dstPath).fileName()))
    return false;

  const QDir srcDir(srcPath);
  const auto infos = srcDir.entryInfoList(QDir::Dirs | QDir::Files | QDir::NoDotAndDotDot);
  for (const QFileInfo &info : infos)
  {
    const QString srcItemPath = srcPath + "/" + info.fileName();
    const QString dstItemPath = dstPath + "/" + info.fileName();
    if (info.isDir())
    {
      if (!copyDir(srcItemPath, dstItemPath))
      {
        return false;
      }
    }
    else if (info.isFile())
    {
      if (!QFile::copy(srcItemPath, dstItemPath))
      {
        return false;
      }
    }
    else
    {
      qDebug() << "Unhandled item" << info.filePath() << "in copyDir";
    }
  }
  return true;
}
}

ApplyScheduledMapUpdates::ApplyScheduledMapUpdates(QObject* parent /* = nullptr */):
  QObject(parent)
{
  // For the purposes of demonstrating the sample,
  // create a temporary copy of the local offline map files,
  // so that updating does not overwrite them permanently
  copyDir(defaultDataPath() + "/" + sampleMmpk, m_TempDir.path() + "/" + sampleMmpk);

  // create MMPK
  m_mobileMapPackage = new MobileMapPackage(m_TempDir.path() + "/" + sampleMmpk, this);

  // load mmpk
  connect(m_mobileMapPackage, &MobileMapPackage::doneLoading, this, &ApplyScheduledMapUpdates::onMmpkDoneLoading);
  m_mobileMapPackage->load();
}

ApplyScheduledMapUpdates::~ApplyScheduledMapUpdates()
{
  if (m_mobileMapPackage)
  {
    m_mobileMapPackage->close();
  }
}

void ApplyScheduledMapUpdates::init()
{
  // Register the map view for QML
  qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
  qmlRegisterType<ApplyScheduledMapUpdates>("Esri.Samples", 1, 0, "ApplyScheduledMapUpdatesSample");
}

void ApplyScheduledMapUpdates::updateMap()
{
  if (!m_offlineSyncTask)
    return;

  m_offlineSyncTask->createDefaultOfflineMapSyncParameters();
}

MapQuickView* ApplyScheduledMapUpdates::mapView() const
{
  return m_mapView;
}

void ApplyScheduledMapUpdates::setMapToMapView()
{
  if (!m_map || !m_mapView)
    return;

  m_mapView->setMap(m_map);
}

void ApplyScheduledMapUpdates::onMmpkDoneLoading(Error e)
{
  // check if successful
  if (!e.isEmpty())
    return;

  // make sure there are valid maps
  if (m_mobileMapPackage->maps().isEmpty())
    return;

  // set the map on the map view
  m_map = m_mobileMapPackage->maps().at(0);
  setMapToMapView();

  // setup sync task
  if (m_offlineSyncTask)
    delete m_offlineSyncTask;

  m_offlineSyncTask = new OfflineMapSyncTask(m_map, this);

  // connect sync task signals
  connectSyncSignals();

  // check for updates
  m_offlineSyncTask->checkForUpdates();
}

// Set the view (created in QML)
void ApplyScheduledMapUpdates::setMapView(MapQuickView* mapView)
{
  if (!mapView || mapView == m_mapView)
    return;

  m_mapView = mapView;

  setMapToMapView();

  emit mapViewChanged();
}

void ApplyScheduledMapUpdates::connectSyncSignals()
{
  // connect to checkForUpdatesCompleted signal and update the UI accordingly
  connect(m_offlineSyncTask, &OfflineMapSyncTask::checkForUpdatesCompleted, this, [this](QUuid, OfflineMapUpdatesInfo* info)
  {
    if (info->downloadAvailability() == OfflineUpdateAvailability::Available)
    {
      emit updateUi(true, "Updates Available", QString("Updates size: %1 bytes").arg(info->scheduledUpdatesDownloadSize()));
    }
    else
    {
      emit updateUi(false, "No updates available", "The preplanned map area is up to date");
    }

    delete info;
  });

  // connect to createDefaultOfflineMapSyncParametersCompleted signal
  connect(m_offlineSyncTask, &OfflineMapSyncTask::createDefaultOfflineMapSyncParametersCompleted, this, [this](QUuid, OfflineMapSyncParameters parameters)
  {
    // set the parameters to download all updates for the mobile map packages
    parameters.setPreplannedScheduledUpdatesOption(PreplannedScheduledUpdatesOption::DownloadAllUpdates);

    // delete and disconnect previous jobs
    if (m_syncJob)
    {
      delete m_syncJob;
      disconnect(m_syncJobConnection);
    }

    // create sync job
    m_syncJob = m_offlineSyncTask->syncOfflineMap(parameters);

    // connect to know when job is complete
    m_syncJobConnection = connect(m_syncJob, &OfflineMapSyncJob::jobDone, this, [this]()
    {
      if (m_syncJob->result()->isMobileMapPackageReopenRequired())
      {
        // close mmpk out
        m_mobileMapPackage->close();
        delete m_mobileMapPackage;

        // load mmpk again with new instance
        m_mobileMapPackage = new MobileMapPackage(m_TempDir.path() + "/" + sampleMmpk, this);
        connect(m_mobileMapPackage, &MobileMapPackage::doneLoading, this, &ApplyScheduledMapUpdates::onMmpkDoneLoading);
        m_mobileMapPackage->load();
      }

      // re-check if updates are available
      m_offlineSyncTask->checkForUpdates();
    });

    // start the job
    m_syncJob->start();
  });
}