From 2b20c61eafb3ec4f526c2812ae2b607064c33f55 Mon Sep 17 00:00:00 2001
From: Matthias Kuhn <matthias@opengis.ch>
Date: Thu, 31 Oct 2019 18:17:26 +0100
Subject: [PATCH] Less global statics in expressions

---
 scripts/process_function_template.py  |  8 +--
 src/core/expression/qgsexpression.cpp |  6 ++
 src/core/qgsexpressionprivate.h       | 82 +++++++++++++++++++++++++++
 3 files changed, 92 insertions(+), 4 deletions(-)

diff --git a/scripts/process_function_template.py b/scripts/process_function_template.py
index c8cf87df3a6..28ffcb22301 100644
--- a/scripts/process_function_template.py
+++ b/scripts/process_function_template.py
@@ -13,11 +13,11 @@ sys.path.append(
 cpp = open(sys.argv[1], "w", encoding="utf-8")
 cpp.write(
     "#include \"qgsexpression.h\"\n"
-    "#include \"qgsexpression_p.h\"\n"
+    "#include \"qgsexpressionprivate.h\"\n"
     "\n"
     "void QgsExpression::initFunctionHelp()\n"
     "{\n"
-    "  if( !sFunctionHelpTexts()->isEmpty() )\n"
+    "  if( functionHelpTexts().isEmpty() )\n"
     "    return;"
 )
 
@@ -76,7 +76,7 @@ for f in sorted(glob.glob('resources/function_help/json/*')):
             if len(list(v['arguments'])) < 1 or len(list(v['arguments'])) > 2:
                 raise BaseException("%s: 1 or 2 arguments expected for operator")
 
-    cpp.write("\n\n  sFunctionHelpTexts()->insert( {0},\n    Help( {0}, tr( \"{1}\" ), tr( \"{2}\" ),\n      QList<HelpVariant>()".format(
+    cpp.write("\n\n  functionHelpTexts().insert( {0},\n    Help( {0}, tr( \"{1}\" ), tr( \"{2}\" ),\n      QList<HelpVariant>()".format(
         name, json_params['type'], json_params['description'])
     )
 
@@ -120,7 +120,7 @@ for f in sorted(glob.glob('resources/function_help/text/*')):
     n = os.path.basename(f)
 
     with open(f) as content:
-        cpp.write("\n\n  sFunctionHelpTexts()->insert( \"{0}\",\n    Help( tr( \"{0}\" ), tr( \"group\" ), tr( \"{1}\" ), QList<HelpVariant>() ) );\n".format(
+        cpp.write("\n\n  functionHelpTexts().insert( \"{0}\",\n    Help( tr( \"{0}\" ), tr( \"group\" ), tr( \"{1}\" ), QList<HelpVariant>() ) );\n".format(
             n, content.read().replace("\\", "&#92;").replace('\\', '\\\\').replace('"', '\\"').replace('\n', '\\n')))
 
 cpp.write("\n}\n")
diff --git a/src/core/expression/qgsexpression.cpp b/src/core/expression/qgsexpression.cpp
index 587dcffdf29..f359a0847d9 100644
--- a/src/core/expression/qgsexpression.cpp
+++ b/src/core/expression/qgsexpression.cpp
@@ -29,9 +29,15 @@
 // from parser
 extern QgsExpressionNode *parseExpression( const QString &str, QString &parserErrorMsg, QList<QgsExpression::ParserError> &parserErrors );
 
+Q_GLOBAL_STATIC( HelpTextHash, sFunctionHelpTexts )
 Q_GLOBAL_STATIC( QgsStringMap, sVariableHelpTexts )
 Q_GLOBAL_STATIC( QgsStringMap, sGroups )
 
+HelpTextHash &functionHelpTexts()
+{
+  return *sFunctionHelpTexts();
+}
+
 bool QgsExpression::checkExpression( const QString &text, const QgsExpressionContext *context, QString &errorMessage )
 {
   QgsExpression exp( text );
diff --git a/src/core/qgsexpressionprivate.h b/src/core/qgsexpressionprivate.h
index 381aee23a90..fead4ecfedc 100644
--- a/src/core/qgsexpressionprivate.h
+++ b/src/core/qgsexpressionprivate.h
@@ -74,6 +74,88 @@ class QgsExpressionPrivate
     //! Whether prepare() has been called before evaluate()
     bool mIsPrepared = false;
 };
+
+
+struct HelpArg
+{
+  HelpArg( const QString &arg, const QString &desc, bool descOnly = false, bool syntaxOnly = false,
+           bool optional = false, const QString &defaultVal = QString() )
+    : mArg( arg )
+    , mDescription( desc )
+    , mDescOnly( descOnly )
+    , mSyntaxOnly( syntaxOnly )
+    , mOptional( optional )
+    , mDefaultVal( defaultVal )
+  {}
+
+  QString mArg;
+  QString mDescription;
+  bool mDescOnly;
+  bool mSyntaxOnly;
+  bool mOptional;
+  QString mDefaultVal;
+};
+
+struct HelpExample
+{
+  HelpExample( const QString &expression, const QString &returns, const QString &note = QString() )
+    : mExpression( expression )
+    , mReturns( returns )
+    , mNote( note )
+  {}
+
+  QString mExpression;
+  QString mReturns;
+  QString mNote;
+};
+
+
+struct HelpVariant
+{
+  HelpVariant( const QString &name, const QString &description,
+               const QList<HelpArg> &arguments = QList<HelpArg>(),
+               bool variableLenArguments = false,
+               const QList<HelpExample> &examples = QList<HelpExample>(),
+               const QString &notes = QString() )
+    : mName( name )
+    , mDescription( description )
+    , mArguments( arguments )
+    , mVariableLenArguments( variableLenArguments )
+    , mExamples( examples )
+    , mNotes( notes )
+  {}
+
+  QString mName;
+  QString mDescription;
+  QList<HelpArg> mArguments;
+  bool mVariableLenArguments;
+  QList<HelpExample> mExamples;
+  QString mNotes;
+};
+
+
+struct Help
+{
+  //! Constructor for expression help
+  Help() = default;
+
+  Help( const QString &name, const QString &type, const QString &description, const QList<HelpVariant> &variants )
+    : mName( name )
+    , mType( type )
+    , mDescription( description )
+    , mVariants( variants )
+  {}
+
+  QString mName;
+  QString mType;
+  QString mDescription;
+  QList<HelpVariant> mVariants;
+};
+
+typedef QHash<QString, Help> HelpTextHash;
+
+HelpTextHash &functionHelpTexts();
+
 ///@endcond
 
 #endif // QGSEXPRESSIONPRIVATE_H