add contains function that also check the datatype

src/knowCore/ValueHash.cpp

@@ -60,6 +60,33 @@ bool ValueHash::contains(const QString& _key) const
   return d->values.contains(_key);
 }
 
+bool ValueHash::contains(const QString& _key, const knowCore::Uri& _datatype) const
+{
+  auto it = d->values.find(_key);
+  if(it != d->values.end())
+  {
+    return it.value().canConvert(_datatype);
+  } else {
+    return false;
+  }
+}
+
+knowCore::ReturnVoid ValueHash::ensureContains(const QString& _key, const knowCore::Uri& _datatype) const
+{
+  auto it = d->values.find(_key);
+  if(it != d->values.end())
+  {
+    if(it.value().canConvert(_datatype))
+    {
+      return kCrvSuccess();
+    } else {
+      return kCrvError("Cannot convert '{}' to '{}'", it.value(), _datatype);
+    }
+  } else {
+    return kCrvError("Missing '{}' in value hash.", _key);
+  }
+}
+
 bool ValueHash::operator==(const ValueHash& _rhs) const
 {
   return d->values == _rhs.d->values;

src/knowCore/ValueHash.h

@@ -48,6 +48,24 @@ namespace knowCore
      * @return if the value is contained in the hash.
      */
     bool contains(const QString& _key) const;
+    /**
+     * @return if the value is contained in the hash and has the given \p _datatype.
+     */
+    bool contains(const QString& _key, const knowCore::Uri& _datatype) const;
+    /**
+     * @return if the value is contained in the hash and is of type \p _T_.
+     */
+    template<typename _T_>
+    bool contains(const QString& _key) const;
+    /**
+     * @return if the value is contained in the hash and has the given \p _datatype.
+     */
+    knowCore::ReturnVoid ensureContains(const QString& _key, const knowCore::Uri& _datatype) const;
+    /**
+     * @return if the value is contained in the hash and is of type \p _T_.
+     */
+    template<typename _T_>
+    knowCore::ReturnVoid ensureContains(const QString& _key) const;
     /**
      * @return attempt to return as a hash of a specific type @arg _T_ if they are convertible to @arg _T_
      */
@@ -156,6 +174,17 @@ namespace knowCore
     struct Private;
     QSharedDataPointer<Private> d;
   };
+
+  template<typename _T_>
+  bool ValueHash::contains(const QString& _key) const
+  {
+    return contains(_key, MetaTypeInformation<_T_>::uri());
+  }
+  template<typename _T_>
+  knowCore::ReturnVoid ValueHash::ensureContains(const QString& _key) const
+  {
+    return ensureContains(_key, MetaTypeInformation<_T_>::uri());
+  }
   
   inline ReturnValue<ValueHash> ValueHash::fromVariantMap(const QVariantMap& _map)
   {