[FEATURE] Expression variables relating to QGIS environment

New variables for:
- @qgis_os_name: eg 'linux','windows' or 'osx'
- @qgis_platform: eg 'desktop' or 'server'
- @user_account_name: current user's operating system account name
- @user_full_name: current user's name from os account (if available)

Sponsored by Andreas Neumann

Author: nyalldawson

python/core/qgsapplication.sip

@@ -228,9 +228,33 @@ static void qtgui_UpdatePyArgv(PyObject *argvlist, int argc, char **argv)
     //! Returns the path to user's style.
     static QString userStyleV2Path();
 
-    //! Returns the short name regular exprecience for line edit validator
+    //! Returns the short name regular expression for line edit validator
     static QRegExp shortNameRegExp();
 
+    /** Returns the user's operating system login account name.
+     * @note added in QGIS 2.14
+     * @see userFullName()
+     */
+    static QString userLoginName();
+
+    /** Returns the user's operating system login account full display name.
+     * @note added in QGIS 2.14
+     * @see userLoginName()
+     */
+    static QString userFullName();
+
+    /** Returns a string name of the operating system QGIS is running on.
+     * @note added in QGIS 2.14
+     * @see platform()
+     */
+    static QString osName();
+
+    /** Returns the QGIS platform name, eg "desktop" or "server".
+     * @note added in QGIS 2.14
+     * @see osName()
+     */
+    static QString platform();
+
     //! Returns the path to user's themes folder
     static QString userThemesFolder();
 

src/core/qgsapplication.cpp

@@ -39,8 +39,14 @@
 
 #ifndef Q_OS_WIN
 #include <netinet/in.h>
+#include <pwd.h>
 #else
 #include <winsock.h>
+#include <windows.h>
+#include <Lmcons.h>
+#define SECURITY_WIN32
+#include <Security.h>
+#pragma comment( lib, "Secur32.lib" )
 #endif
 
 #include "qgsconfig.h"
@@ -72,6 +78,10 @@ QStringList ABISYM( QgsApplication::mGdalSkipList );
 int ABISYM( QgsApplication::mMaxThreads );
 QString ABISYM( QgsApplication::mAuthDbDirPath );
 
+QString QgsApplication::sUserName;
+QString QgsApplication::sUserFullName;
+QString QgsApplication::sPlatformName = "desktop";
+
 const char* QgsApplication::QGIS_ORGANIZATION_NAME = "QGIS";
 const char* QgsApplication::QGIS_ORGANIZATION_DOMAIN = "qgis.org";
 const char* QgsApplication::QGIS_APPLICATION_NAME = "QGIS2";
@@ -89,9 +99,11 @@ const char* QgsApplication::QGIS_APPLICATION_NAME = "QGIS2";
   so that platform-conditional code is minimized and paths are easier
   to change due to centralization.
 */
-QgsApplication::QgsApplication( int & argc, char ** argv, bool GUIenabled, const QString& customConfigPath )
+QgsApplication::QgsApplication( int & argc, char ** argv, bool GUIenabled, const QString& customConfigPath, const QString& platformName )
     : QApplication( argc, argv, GUIenabled )
 {
+  sPlatformName = platformName;
+
   init( customConfigPath ); // init can also be called directly by e.g. unit tests that don't inherit QApplication.
 }
 
@@ -722,6 +734,93 @@ QRegExp QgsApplication::shortNameRegExp()
   return QRegExp( "^[A-Za-z][A-Za-z0-9\\._-]*" );
 }
 
+QString QgsApplication::userLoginName()
+{
+  if ( !sUserName.isEmpty() )
+    return sUserName;
+
+#ifdef Q_OS_WIN
+  TCHAR name [ UNLEN + 1 ];
+  DWORD size = UNLEN + 1;
+
+  if ( GetUserName(( TCHAR* )name, &size ) )
+  {
+    sUserName = QString( name );
+  }
+
+#else
+  QProcess process;
+
+  process.start( "whoami" );
+  process.waitForFinished();
+  sUserName = process.readAllStandardOutput().trimmed();
+#endif
+
+  if ( !sUserName.isEmpty() )
+    return sUserName;
+
+  //backup plan - use environment variables
+  sUserName = qgetenv( "USER" );
+  if ( !sUserName.isEmpty() )
+    return sUserName;
+
+  //last resort
+  sUserName = qgetenv( "USERNAME" );
+  return sUserName;
+}
+
+QString QgsApplication::userFullName()
+{
+  if ( !sUserFullName.isEmpty() )
+    return sUserFullName;
+
+#ifdef Q_OS_WIN
+  TCHAR name [ UNLEN + 1 ];
+  DWORD size = UNLEN + 1;
+
+  //note - this only works for accounts connected to domain
+  if ( GetUserNameEx( NameDisplay, ( TCHAR* )name, &size ) )
+  {
+    sUserFullName = QString( name );
+  }
+
+  //fall back to login name
+  if ( sUserFullName.isEmpty() )
+    sUserFullName = userLoginName();
+#else
+  struct passwd *p = getpwuid( getuid() );
+
+  if ( p )
+  {
+    QString gecosName = QString( p->pw_gecos );
+    sUserFullName = gecosName.left( gecosName.indexOf( ',', 0 ) );
+  }
+
+#endif
+
+  return sUserFullName;
+}
+
+QString QgsApplication::osName()
+{
+#if defined(Q_OS_ANDROID)
+  return QLatin1String( "android" );
+#elif defined(Q_OS_MAC)
+  return QLatin1String( "osx" );
+#elif defined(Q_OS_WIN)
+  return QLatin1String( "windows" );
+#elif defined(Q_OS_LINUX)
+  return QLatin1String( "linux" );
+#else
+  return QLatin1String( "unknown" );
+#endif
+}
+
+QString QgsApplication::platform()
+{
+  return sPlatformName;
+}
+
 QString QgsApplication::userThemesFolder()
 {
   return qgisSettingsDirPath() + QLatin1String( "/themes" );

src/core/qgsapplication.h

@@ -38,7 +38,7 @@ class CORE_EXPORT QgsApplication : public QApplication
     static const char* QGIS_ORGANIZATION_NAME;
     static const char* QGIS_ORGANIZATION_DOMAIN;
     static const char* QGIS_APPLICATION_NAME;
-    QgsApplication( int & argc, char ** argv, bool GUIenabled, const QString& customConfigPath = QString() );
+    QgsApplication( int & argc, char ** argv, bool GUIenabled, const QString& customConfigPath = QString(), const QString& platformName = "desktop" );
     virtual ~QgsApplication();
 
     /** This method initialises paths etc for QGIS. Called by the ctor or call it manually
@@ -190,9 +190,33 @@ class CORE_EXPORT QgsApplication : public QApplication
     //! Returns the path to user's style.
     static QString userStyleV2Path();
 
-    //! Returns the short name regular exprecience for line edit validator
+    //! Returns the short name regular expression for line edit validator
     static QRegExp shortNameRegExp();
 
+    /** Returns the user's operating system login account name.
+     * @note added in QGIS 2.14
+     * @see userFullName()
+     */
+    static QString userLoginName();
+
+    /** Returns the user's operating system login account full display name.
+     * @note added in QGIS 2.14
+     * @see userLoginName()
+     */
+    static QString userFullName();
+
+    /** Returns a string name of the operating system QGIS is running on.
+     * @note added in QGIS 2.14
+     * @see platform()
+     */
+    static QString osName();
+
+    /** Returns the QGIS platform name, eg "desktop" or "server".
+     * @note added in QGIS 2.14
+     * @see osName()
+     */
+    static QString platform();
+
     //! Returns the path to user's themes folder
     static QString userThemesFolder();
 
@@ -378,6 +402,10 @@ class CORE_EXPORT QgsApplication : public QApplication
     /**
      * @note added in 2.12 */
     static QString ABISYM( mAuthDbDirPath );
+
+    static QString sUserName;
+    static QString sUserFullName;
+    static QString sPlatformName;
 };
 
 #endif

src/core/qgsexpression.cpp

@@ -4432,6 +4432,10 @@ void QgsExpression::initVariableHelp()
   gVariableHelpTexts.insert( "qgis_version", QCoreApplication::translate( "variable_help", "Current QGIS version string." ) );
   gVariableHelpTexts.insert( "qgis_version_no", QCoreApplication::translate( "variable_help", "Current QGIS version number." ) );
   gVariableHelpTexts.insert( "qgis_release_name", QCoreApplication::translate( "variable_help", "Current QGIS release name." ) );
+  gVariableHelpTexts.insert( "qgis_os_name", QCoreApplication::translate( "variable_help", "Operating system name, eg 'windows', 'linux' or 'osx'." ) );
+  gVariableHelpTexts.insert( "qgis_platform", QCoreApplication::translate( "variable_help", "QGIS platform, eg 'desktop' or 'server'." ) );
+  gVariableHelpTexts.insert( "user_account_name", QCoreApplication::translate( "variable_help", "Current user's operating system account name." ) );
+  gVariableHelpTexts.insert( "user_full_name", QCoreApplication::translate( "variable_help", "Current user's operating system user name (if available)." ) );
 
   //project variables
   gVariableHelpTexts.insert( "project_title", QCoreApplication::translate( "variable_help", "Title of current project." ) );

src/core/qgsexpressioncontext.cpp

@@ -25,6 +25,7 @@
 #include "qgscomposition.h"
 #include "qgscomposeritem.h"
 #include "qgsatlascomposition.h"
+#include "qgsapplication.h"
 #include <QSettings>
 #include <QDir>
 
@@ -465,6 +466,10 @@ QgsExpressionContextScope* QgsExpressionContextUtils::globalScope()
   scope->addVariable( QgsExpressionContextScope::StaticVariable( "qgis_version", QGis::QGIS_VERSION, true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( "qgis_version_no", QGis::QGIS_VERSION_INT, true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( "qgis_release_name", QGis::QGIS_RELEASE_NAME, true ) );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( "qgis_platform", QgsApplication::platform(), true ) );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( "qgis_os_name", QgsApplication::osName(), true ) );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( "user_account_name", QgsApplication::userLoginName(), true ) );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( "user_full_name", QgsApplication::userFullName(), true ) );
 
   return scope;
 }

src/server/qgsserver.cpp

@@ -330,7 +330,7 @@ bool QgsServer::init( int & argc, char ** argv )
     QSettings::setPath( QSettings::IniFormat, QSettings::UserScope, optionsPath );
   }
 
-  mQgsApplication = new QgsApplication( argc, argv, getenv( "DISPLAY" ) );
+  mQgsApplication = new QgsApplication( argc, argv, getenv( "DISPLAY" ), QString(), "server" );
 
   QCoreApplication::setOrganizationName( QgsApplication::QGIS_ORGANIZATION_NAME );
   QCoreApplication::setOrganizationDomain( QgsApplication::QGIS_ORGANIZATION_DOMAIN );

tests/src/core/testqgsapplication.cpp

@@ -29,6 +29,11 @@ class TestQgsApplication: public QObject
     void checkGdalSkip();
     void initTestCase();
     void cleanupTestCase();
+
+    void accountName();
+    void osName();
+    void platformName();
+
   private:
     QString getQgisPath();
 };
@@ -50,6 +55,34 @@ void TestQgsApplication::cleanupTestCase()
   QgsApplication::exitQgis();
 }
 
+void TestQgsApplication::accountName()
+{
+  QString loginName = QgsApplication::userLoginName();
+  qDebug() << QString( "Got login name: '%1'" ).arg( loginName );
+  QVERIFY( !loginName.isEmpty() );
+  //test cached return works correctly
+  QCOMPARE( loginName, QgsApplication::userLoginName() );
+
+  //can't test contents, as it can be validly empty (eg on Travis). Just testing that we don't crash
+  QString fullName = QgsApplication::userFullName();
+  qDebug() << QString( "Got full name: '%1'" ).arg( fullName );
+  //test cached return works correctly
+  QCOMPARE( fullName, QgsApplication::userFullName() );
+}
+
+void TestQgsApplication::osName()
+{
+  // can't test expected result, so just check for non-empty result
+  qDebug() << QString( "Got OS name: '%1'" ).arg( QgsApplication::osName() );
+  QVERIFY( !QgsApplication::osName().isEmpty() );
+}
+
+void TestQgsApplication::platformName()
+{
+  // test will always be run under desktop platform
+  QCOMPARE( QgsApplication::platform(), QString( "desktop" ) );
+}
+
 void TestQgsApplication::checkPaths()
 {
   QString myPath = QgsApplication::authorsFilePath();

tests/src/core/testqgsexpressioncontext.cpp

@@ -488,10 +488,18 @@ void TestQgsExpressionContext::globalScope()
   QgsExpression expVersion( "var('qgis_version')" );
   QgsExpression expVersionNo( "var('qgis_version_no')" );
   QgsExpression expReleaseName( "var('qgis_release_name')" );
+  QgsExpression expAccountName( "var('user_account_name')" );
+  QgsExpression expUserFullName( "var('user_full_name')" );
+  QgsExpression expOsName( "var('qgis_os_name')" );
+  QgsExpression expPlatform( "var('qgis_platform')" );
 
   QCOMPARE( expVersion.evaluate( &context ).toString(), QString( QGis::QGIS_VERSION ) );
   QCOMPARE( expVersionNo.evaluate( &context ).toInt(), QGis::QGIS_VERSION_INT );
   QCOMPARE( expReleaseName.evaluate( &context ).toString(), QString( QGis::QGIS_RELEASE_NAME ) );
+  QCOMPARE( expAccountName.evaluate( &context ).toString(), QgsApplication::userLoginName() );
+  QCOMPARE( expUserFullName.evaluate( &context ).toString(), QgsApplication::userFullName() );
+  QCOMPARE( expOsName.evaluate( &context ).toString(), QgsApplication::osName() );
+  QCOMPARE( expPlatform.evaluate( &context ).toString(), QgsApplication::platform() );
 
   //test setGlobalVariables
   QgsStringMap vars;