Creating a code template to generate classes
Creating a code template
To create your new code template, select the JavaProfileImplementation
J profile implementation previously created and click on the 
icon. The
Code template window then appears.
Note: Code templates can only be created on J profile implementations in J MDA components. It is not possible to create a code template for a Java MDA component.
For the purposes
of our example, we are going to change the name of the code template we have
just created, by carrying out the following steps:
1.
Select the
name of the code template on the top left of the window shown in Figure 14.
2.
Click once
on it (or press F
3.
Enter the
new name (in our example, ClassJavaTemplate) for the code template.
Note: This operation can also be carried out in the MDA Modeler explorer.
Defining the metaclass
on which your template will run
The very first
step is to define the metaclass on which the code template you are about to
build will be run, in our example, the Class metaclass. To do this,
carry out the steps shown in Figure 14.
Figure 14. Defining
the metaclass in the Code template creation window
Steps:
1.
Click on
the browse button on the right of the Metaclass field. The Select
a metaclass window then appears. Select the Class metaclass
(located in the Objecteering UML/Metamodel package) and click on OK
to confirm.
Note: You can either select a metaclass directly in the metamodel tree or simply type the name of the metaclass in the field. If you choose to enter the metaclass name, you will see that even if you only enter the first few letters of the name, MDA Modeler will select the first available metaclass corresponding to this entry (for example, if you enter pack, the Package metaclass is automatically selected in the metamodel tree). The field is not case sensitive.
Creating a skeleton node for the class
Skeleton nodes
are used to reference the skeleton file containing the structure of the file to
be generated.
Figure 15. Creating
a skeleton node
Steps:
1.
Select the
template node you created in Figure 14.
2.
Click on
the 
icon. The new skeleton node then appears. Name
it skeletonClass.
Continue by creating a "class.skel" file whose contents are as follows:
class <%= Name
%> {
<% Attributes
%>
<% Operations
%>
}
This file should
be saved in the OBJING_PATH/mdaplugs/JavaGenerator/
When the
template is evaluated:
·
<%= Name %> will be
replaced by the name of the class. It is a J expression.
·
<% Attributes %>
will be replaced by the text generated by the Attributes navigation
node that will be created in the following sections.
·
<% Operations %>
will be replaced by the text generated by the Operations navigation
node that will be created in the following sections.
The "class.skel" file you
have just created must now be associated with the skeleton node. To do this, simply select the skeleton node
and then click in the "Associated skeleton" field on the right of the
window. Next, click on the 
button to open a file browser, in which you
can select the "class.skel" file in the ""OBJING_PATH/mdaplugs//JavaGenerator/1.0/templates" directory.
For more
information on creating skeleton nodes, please see Code
templates.
Creating a
navigation node to retrieve attributes
We are now going
to create a navigation node, which will be used to retrieve the attributes of
the class, as well as to process each attribute.
Figure 16. Creating
the Attributes navigation node
Steps:
1.
Select the
skeletonClass skeleton node you have just created.
2.
Click on
the 
icon.
The Create a navigation node window then appears.
3.
Select Attributes
from the list.
4.
Click on OK
to confirm.
For more
information on creating navigation nodes, please see Creating navigation nodes.
Creating a skeleton
node for the attribute
We are now going to create a skeleton node for the attribute. To do this, carry out the steps shown in Figure 17 below.
Figure 17. Creating
a skeleton node for the attribute
Steps:
1.
Select the
Attributes navigation node you created in Figure
2.
Clicking
on the icon. The new skeleton node then appears. Name
it skeletonAttribute.
3.
Define its
Indentation by giving it the
following value: increase.
4.
Enter
"type" in the "Alias" field, and copy the following code
into the "Replacement content" :
{
TypeGeneralClass {
return = Name;
}
if (IsSet) return.strcat ("[]");
if (return == "") return = "void";
}
Next, create an
attribute.skel file whose contents are as follows:
//
Attribute: <%= Name %>
<%$ type %>
<%= Name %>;
This file must
be saved in the OBJING_PATH/mdaplugs/JavaGenerator/1.0/templates directory.
This directory corresponds to the workspace of the MDA component.
When the
template is evaluated:
·
<%= Name %> will be
replaced by the name of the class. It is a J expression.
·
<%$ type %> will
be replaced by the text generated by the type alias
The "attribute.skel" file
you have just created must now be associated with the skeleton node. To do this, simply select the
"skeletonAttribute" skeleton node and then click in the
"Associated skeleton" field on the right of the window. Next, click on the button to open a file browser, in which you
can select the "attribute.skel" file in the ""OBJING_PATH/mdaplugs//JavaGenerator/1.0/templates" directory.
For more
information on creating skeleton nodes, please see Code
templates.
Creating a
navigation node to retrieve operations
We are now going
to create a navigation node, which will be used to retrieve the operations of
the class, as well as to process each operation.
Figure 18. Creating
the Operations navigation node
Steps:
1.
Select the
skeletonClass skeleton node you created in Figure
2.
Click on
the icon.
The Create a navigation node window then appears.
3.
In this
window, select Operations from the list.
4.
Click on OK
to confirm.
For more
information on creating navigation nodes, please see Creating navigation nodes.
Creating a skeleton
node for the operation
Figure 19. Creating
a skeleton node for the operation
Steps:
1.
Select the
Operations navigation node you created in Figure
2.
Click on
the icon. The new skeleton node then appears. Name
it "skeletonOperation".
3.
Define its
Indentation by giving it the
following value: increase.
4.
Enter
"returnParameter" in the "Alias" field and then copy
the following code into the "Replacement content" field:
{
ReturnParameter {
TypeGeneralClass {
return = Name;
}
if (IsSet) return.strcat ("[]");
}
if (return == "") return = "void";
}
5. Define an ioParameters alias, with the following in the Replacement content field:
{
String indent = " ";
IOParameter {
if (ParameterPassing == In) return.strcat ("in ");
else if (ParameterPassing == Out) return.strcat ("out ");
else if (ParameterPassing == Inout) return.strcat ("inout ");
return.strcat (TypeGeneralClass.Name);
if (IsSet) return.strcat ("[]");
return.strcat (" ",
Name, ",", NL, indent);
}
return.strip (", " + NL);
if (IOParameter.size() > 1) {
return.prepend (indent);return.prepend (NL);
}
}
Continue by
creating an operation.skel file whose contents are as follows:
// Operation "<%= Name %>"
<%= {if (isTaggedValue ("synchronized")) return.strcat ("synchronized ");} %><%$ returnParameter %>
<%= Name %> (<%$ ioParameters %>) {
// Code
<% CodeNote %>
} // operation <%= Name %>
This file must
be saved in the OBJING_PATH/mdaplugs/JavaGenerator/1.0/templates directory.
This directory corresponds to the workspace of the MDA component.
When the
template is evaluated:
·
<%= Name %> will be
replaced by the name of the class. It is a J expression.
·
<%= {if (isTaggedValue ("synchronized")) return.strcat
("synchronized ");} %>
will be replaced by synchronized, if the operation has the {synchronized}
tagged value. It is a J expression.
·
<% returnParameter %> will be replaced by the text generated by the returnParameter
alias.
·
<% ioParameters %>
will be replaced by the text generated by the ioParameters alias.
·
<% CodeNote %>
will be replaced by the text generated by the CodeNote navigation node
that will be created next.
The "operation.skel" file
you have just created must now be associated with the skeleton node. To do this, simply select the
"skeletonOperation" skeleton node and then click in the
"Associated skeleton" field on the right of the window. Next, click on the button to open a file browser, in which you
can select the "operation.skel" file in the ""OBJING_PATH/mdaplugs/JavaGenerator/1.0/templates" directory.
For more
information on creating skeleton nodes, please see Code
templates.
Creating a
navigation node to retrieve notes
We are now going
to create a navigation node, which will be used to retrieve notes.
Figure 20. Creating
the "Notes" navigation node
Steps:
1.
Select the
skeletonOperation skeleton node you have just created.
2.
Click on
the icon.
The Create a navigation node window then appears.
3.
In this
window, select Notes from the list, and click on OK to
confirm.
4.
Change the
name of the new navigation node to CodeNote (by selecting it, pressing
F
5.
Define the
Filter property of the navigation node by entering the following: "(ModelNoteType != null) && (ModelNoteType.Name ==
"JavaCode")".
For more
information on creating navigation nodes, please see Creating navigation nodes.
Creating an
expression to generate the contents of the note
We are now going
to create an expression, which will be used to generate the contents of the
note.
Figure 21. Creating
an expression to generate the contents of the note
Steps:
1.
Select the
CodeNote navigation node you have just created.
2.
Click on
the 
icon. The new expression then appears.
3.
Define the
Value property of the expression node by entering the following: Content
For more
information on creating navigation nodes, please see Code
templates.
Click on the OK
button to validate the template. At any time, you can save your modifications
without closing the window by clicking on the Apply button.