conversion-rulenode allows you to write customized code to convert the given argument between the target language and C++. It is then a child of the modify-argument node:<modify-argument index="2"> <!-- for the second argument of the function --> <conversion-rule class="target | native"> // the code </conversion-rule> </modify-argument>
classattribute accepts one of the following values to define the conversion direction to be either
native: Defines the conversion direction to be
It is similar to the existing
<target-to-native>element. See Conversion Rule Tag for more information.
target: Defines the conversion direction to be
It is similar to the existing
<native-to-target>element. See Conversion Rule Tag for more information.
This node is typically used in combination with the replace-type and remove-argument nodes. The given code is used instead of the generator’s conversion code.
Writing %N in the code (where N is a number), will insert the name of the nth argument. Alternatively, %in and %out which will be replaced with the name of the conversion’s input and output variable, respectively. Note the output variable must be declared explicitly, for example:<conversion-rule class="native"> bool %out = (bool) %in; </conversion-rule>
You can also use the
conversion-rulenode to specify a conversion code which will be used instead of the generator’s conversion code everywhere for a given type.
remove-argumentnode removes the given argument from the function’s signature, and it is a child of the modify-argument node.<modify-argument> <remove-argument /> </modify-argument>
rename tonode is used to rename a argument and use this new name in the generated code, and it is a child of the modify-argument node.<modify-argument> <rename to='...' /> </modify-argument>
This tag is deprecated, use the
rename attribute from modify-argument tag instead.
remove-default-expressionnode disables the use of the default expression for the given argument, and it is a child of the modify-argument node.<modify-argument...> <remove-default-expression /> </modify-argument>
replace-default-expressionnode replaces the specified argument with the expression specified by the
withattribute, and it is a child of the modify-argument node.<modify-argument> <replace-default-expression with="..." /> </modify-argument>
replace-typenode replaces the type of the given argument to the one specified by the
modified-typeattribute, and it is a child of the modify-argument node.<modify-argument> <replace-type modified-type="..." /> </modify-argument>
If the new type is a class, the
modified-typeattribute must be set to the fully qualified name (including name of the package as well as the class name).
define-ownershiptag indicates that the function changes the ownership rules of the argument object, and it is a child of the modify-argument node. The
classattribute specifies the class of function where to inject the ownership altering code (see Code Generation Terminology). The
ownerattribute specifies the new ownership of the object. It accepts the following values:
- target: the target language will assume full ownership of the object.
The native resources will be deleted when the target language object is finalized.
- c++: The native code assumes full ownership of the object. The target
language object will not be garbage collected.
- default: The object will get default ownership, depending on how it
was created.<modify-argument> <define-ownership class="target | native" owner="target | c++ | default" /> </modify-argument>
reference-counttag dictates how an argument should be handled by the target language reference counting system (if there is any), it also indicates the kind of relationship the class owning the function being modified has with the argument. It is a child of the modify-argument node. For instance, in a model/view relation a view receiving a model as argument for a setModel method should increment the model’s reference counting, since the model should be kept alive as much as the view lives. Remember that out hypothetical view could not become parent of the model, since the said model could be used by other views as well. The
actionattribute specifies what should be done to the argument reference counting when the modified method is called. It accepts the following values:
add: increments the argument reference counter.
add-all: increments the reference counter for each item in a collection.
remove: decrements the argument reference counter.
set: will assign the argument to the variable containing the reference.
- ignore: does nothing with the argument reference counter
- (sounds worthless, but could be used in situations
where the reference counter increase is mandatory by default).<modify-argument> <reference-count action="add|add-all|remove|set|ignore" variable-name="..." /> </modify-argument>
The variable-name attribute specifies the name used for the variable that holds the reference(s).
replace-valueattribute lets you replace the return statement of a function with a fixed string. This attribute can only be used for the argument at
index0, which is always the function’s return value.<modify-argument index="0" replace-value="this"/>
parentnode lets you define the argument parent which will take ownership of argument and will destroy the C++ child object when the parent is destroyed (see Parent-child relationship). It is a child of the modify-argument node.<modify-argument index="1"> <parent index="this" action="add | remove" /> </modify-argument>
indexargument you must specify the parent argument. The action add creates a parent link between objects, while remove will undo the parentage relationship.