conversion-rule node 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>
class attribute 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.
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-rule node to specify
a conversion code which will be used instead of the generator’s conversion code everywhere for a given type.
remove-argument node 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 to node 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-expression node 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-expression node replaces the specified argument with the
expression specified by the
with attribute, and it is a child of the
<modify-argument> <replace-default-expression with="..." /> </modify-argument>
replace-type node replaces the type of the given argument to the one
specified by the
modified-type attribute, and it is a child of the
<modify-argument> <replace-type modified-type="..." /> </modify-argument>
If the new type is a class, the
modified-type attribute must be set to
the fully qualified name (including name of the package as well as the class
define-ownership tag indicates that the function changes the ownership
rules of the argument object, and it is a child of the
class attribute specifies the class of
function where to inject the ownership altering code
(see Code Generation Terminology). The
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
<modify-argument> <define-ownership class="target | native" owner="target | c++ | default" /> </modify-argument>
reference-count tag 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.
action attribute specifies what should be done to the argument
reference counting when the modified method is called. It accepts the
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-value attribute lets you replace the return statement of a
function with a fixed string. This attribute can only be used for the
index 0, which is always the function’s return value.
<modify-argument index="0" replace-value="this"/>
parent node 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>
index argument you must specify the parent argument. The action
add creates a parent link between objects, while remove will undo the