JDeveloper 12.1.3: Using File Templates

Since JDeveloper 12.1.2 Oracle added a feature called ‘File Templates’. Only there was absolutely no documentation for this. We only had the ‘File Templates’ node in the preferences. I filed a bug (ADFEMG-150) for this.
In the current JDeveloper 12.1.3 release the ‘inital’ documentation for the ‘File Templated’ has been added.
To get to the ‘File Templates’ via the Tools->Preferences->’File Tempalates’ and see the below image.

File Templates in Preferences

File Templates in Preferences

Loading the extension you get
FileT emplates Inital Dialog

File Templates Inital Dialog

The only help I found can be reached by clicking the Help button in the dialog which will get you
File Templates Help

File Templates Help

This is not much to work with. I you find more help on using this feature, drop me a note, please. All I present in this blog was found out using try and error. There seams to be a difference if you use a Windows or Unix based machine. Later in the blog I’ll give more info on this.

Let’s start with my findings. Clicking through the tree shown in the image above you quickly get the intention of the file templates. This feature allows us to define template for files (e.g. java classes) which can be used to define repeating code and generate the files from it. The sample which is provided by Oracle builds a template for a java class containing copyright and licence information.

However, there is no button or menu to create your own template from scratch. The pencil icon in the top right corner is disabled for each of the files. The only way to create a new template file is to copy an existing one by using the ‘Copy’ button. The first time you click the copy button for one of the files in the you get a note that you can’t change the files in place:
Confirm Modify Template

Confirm Modify Template

confirming the dialog with yes, a copy the content of the sample template from the jar will be created into a file you can edit. All custom template files are written to system12.\o.jdeveloper.filetemplate\ folder by default. While copying the files you can change the ID, description, the Name and the file name of the template.

Please not the properties in the dialog which allows to define where you later find the template in the gallery.
Once we have copied all files from the tree we can start to modify them. The file suffix of the templates is ‘ftl’. The copied files are automatically opened in the JDev editor. Here comes the first glitch in the extension. If you change *.ftl files in the JDev editor and hit the ‘Save All’ button, the files are not saved. The caption of the tabs remains italic, meaning that the content of the tab has changed and is not saved. You need to hit the ‘Save’ button to save each file by itself.
Once the templates are copied into an accessible path, you can use the ‘Pencil’ button to open them again in the JDev editor, or you can make small changes directly in the editor window in the dialog.
Looking at the content of the files you see that ‘copyright-hahn-java.ftl’ inludes ‘license-hahn-txt.ftl’ which then includes ‘copyright-hahn-content.ftl’. This is the first file we change to change the copyright notice
Changed Copyright Text

Changed Copyright Text

To make the licence ‘license-hahn-txt.ftl’ pick up the changes copyright text we have to change the include statement in the licence template
Change Include  of Copyright in Licence Template

Change Include of Copyright in Licence Template

and finally we have to change the ‘copyright-hahn-java.ftl’ to pickup the changes licence template
Change Include of Licence in Template

Change Include of Licence in Template

After saving all changes (remember to save each file separately) we can test the template. For this we select a package in a project, right click the package we want the file created in and select ‘New’->’From Gallery…’
Select 'New'->'From Gallery...'

Select ‘New’->’From Gallery…’

When we save the java call template we saved the information where the template shows up via the ‘Category’, ‘Folder’ and ‘Feature’ properties of the template dialog (these properties define where the template shown up in the gallery). Select ‘Java’ and you should see
Select the Template from the Gallery

Select the Template from the Gallery

Please notice the name which is the ID we chose for the template and the description which comes from the save dialog too. Select the template and you get the file save dialog
File Save Dialog

File Save Dialog

In the JDev editor you get the generated java class
Generated Class from Template

Generated Class from Template

Please note the error in line 26 of the generated java class

package de/hahn/blog/test1213/.model/adfbc/;

should be

package de.hahn.blog.test1213.model.adfbc;

This only happens on Windows machines, Unix machines generate the right package statement. You have to correct this yourself. I’ll file an bug this.

Now that we have seen this sample, let’s ask what’s missing.

    1) Documentation: if you look at the templates you seethe usage of variables in the templates like ‘${name}’ or ‘${package}’, however, I could not find if there any other valuables as the once you see in the sample. Same is true for the language behind the template mechanism. The sample show some kind of ternary operator, question is what other options do we have. The file suffix ‘.ftl’ and some other information I gathered for this blog post, suggests that the templates are using a tool named ‘FreeMarker’.
    2) Use cases: I would like to use templates at other points like java classes generated for ViewObjectImpl, EntityObjecImpl or ApplicationModuleImpl. This is not possible right now. It would be handy e.g. to generate files with ADFLogger directly implemented. You can insert the ADFLogger into the class using the template, but as this is only done for classes you create via the template most of the other generated classed need to be changed by hand.
    3) applying the template to an existing class is not possible. If you like a copyright statement in each class you can’t attach it from a template.

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