JDev 12.2.1.3: Creating a shared skin jar (Part 2)

In part 1 or the series we created a simple skin, built an ADF-Library from it and tried to reuse it by deploying it to a WebLogic Server. This approach failed. In this part, we try another option to share a jar with

Sharing the skin with other applications

To share the skin with other application we can

  1. Create an ADF Library
    1. Add this library to the other application
    2. Add this library as a shared library to a WebLogic Server
  2. Create a normal jar
    1. Add this library to the other application
    2. Add this library as a shared library to a WebLogic Server

For this blog the way we want to use if 2b. This allows to create the skin once, deploy it to a server and use it in every other application. In the next paragraph, we try out option 1a to show the problems when reading resources from a jar file.

Using a shared skin

Option 2b

Here we create a jar file containing the skin and additional resources like images and deploy it directly to a WebLogic Server as a shared library. The advantage is, that other applications can use the skin and other resources directly and that the jar can be versioned to allow different versions of the same jar on the server.

Option 1a which we discussed in the previous chapter doesn’t work for images. However, the documentation ‘Deploying a Custom Skin File in a JAR File’ and Frank Nimphius pointed it out in e.g. 86. Reading boilerplate images and icons from a JAR or How-to share skin definition files across applications how the jar file must be structured to allow the resource servlet to read the resources. The essential sentence is

‘All image resources and CSS files must also be under the META-INF directory.’

In his article, Frank suggested using the command line jar tool to create the jar. I show how to use JDev to create the jar with the needed structure and how to deploy it to a server as a shared library.

A sample application is used to use the skin and to show an image load from the jar.

The building plan for a skin in a shared Library which can be deployed to a WebLogic server is given in the article as:

To implement the shared library approach, developers need to change their existing skin definition so it can be deployed in a JAR file. The steps for this include

– Creating a META-INF directory – Creating a trinidad-skins.xml file that defines the skins deployed with the JAR file

– Creating an META-INF/adf sub directory for images and icons served from the JAR file

– Changing the image reference in the CSS to include the “adf” directory, which makes sure images and icons are handled by the ADF Faces resource loader, which can read resources from JAR files

– JAR the META-INF directory to create the library file

Looking at the current project for the skin we see a different layout

In the article Frank instructed to create the needed folders yourself and copying or moving the files to the new structure, then to use the command line to build a jar from the structure.

I’ll show how this can be done with a special deployment descriptor from within the project. The image below shows the needed layout of the final jar file.

To transform the folder structure present in JDev to the needed structure of the final jar, we create a new deployment descriptor in JDev

In image 4 we see the first part of the solution: here we set the path inside the jar to ‘MEAT-INF’. This will guarantee the structure we need. Then we add another contributor to the list (public_html) to get everything we need into this folder. Then we use the ‘Filters’ node to select all content we need skin part

Next part is to create another path in the jar for the metadata of the skin

We add another file group for the resources

Now we can deploy the jar using the new deployment descriptor

And the jar file is created in the deploy folder. It holds all files in the right folders

Finally, we can deploy this jar to the WebLogicServer. In this case, I use the integrated WLS, but it can be any stand-alone WLS too.

The error message you see on the 7th image can be ignored. It only tells you that the library can’t be deployed as an application but only as a shared library. This is exactly what we want to do 🙂

Now the jar file is deployed on the WLS as a shared library and can be used for every application on this server.

We use the existing application from part one to consume the jar skin from the shared library and show the images deployed with the jar.

Before we go any further, we have to remove the ADF Library we added to show the problem from the project. For this open the project properties and select the ‘Library/Classpath’ node and remove the ‘ADFLibrary’ entry

The page should now look like no skin is used at all.

As we already added a skin (with the ADF Library) we don’t have to do this again. However, we have to add a library reference to configure the application to use the shared library deployed on the server. For this, we open the application descriptors and edit the ‘weblogic-application.xml’ file by double clicking the entry in the application resources section

In the ‘Shared Library Reference’ section, we add a reference to the now deployed shared jar ‘blogsharedskin’

Saving everything we don’t see any change to the page design, as the library isn’t part of the application yet. Starting the application we get

Just what we liked to see. The images are visible, checking the page with Chrome’s Dev Tools shows that the images are correctly loaded

This proves that the shared library with the skin and the images are working correctly.

To make the skin visible in JDev during development, we can add the jar we developed to the server a library. We create a library

and make sure the ‘Deploy by default’ is NOT set. Adding the library to the project

will make the skin visible in design mode

The unset checkmark prevents the jar from being packed into the WAR or EAR file. It’s just used in the IDE. That you can’t see the images is normal as there is no full server to serve the images to the design view.

Summary

In this mini-series, I showed the problem when creating a skin as ADF Library and trying to share it on a Weblogic Server. Then I showed how to create a deployment descriptor for the skin and other resources and how to deploy the resulting jar to a WebLogic Server.

The sample application can be downloaded from BlogSharedSkin. The sample was created by using JDev 12.2.1.3 but the same technique can be used in any 12.2.1.x JDev version. There is no database connection needed.

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JDev 12.2.1.3: Creating a shared skin jar (Part 1)

In earlier versions of JDev, skins have been created either by pure code or by using the free Skin Editor. However, since JDev 12.2.1.x the skin editor has been integrated into JDeveloper itself.

A couple of questions in the ODC JDeveloper space are about how to create a skin with JDev which can be deployed as a shared library to a WebLogic Server. I gave this a try and it turned out, that you can build an ADF library jar from a skin project but you can’t use images to this jar which you might want to use in the application.

In this blog, I’ll show how to create a skin with resources like images and how to build a jar file from the skin together with the images and deploy it aa s shared jar to a WeblogicServer.

Building a skin project

The first part is to build a small skin project. The project we use to create a minimal skin, just to show that the skin is changing something. Then we add some images to the skin which we want to use in the application which uses the skin. Such images can e.g. used on an af:button component.

We start by creating a new application as an ‘ADF Fusion Web Application’

As we don’t need the created model project we delete it completely

If you get another dialog, telling you that you can’t undo the action, answer ‘Yes’ to delete the project. Now you should see a workspace with just the one project:

Know that we have a project we add a skin and e.g. add some skin selectors to change to the color of the button text. For this, we right click the ‘Web Content’ folder in the project and select ‘New from Garaly’ and then select ‘ADF Skin’ from the ‘JSF/Facelets’ node and fill in the basic information:

This will create the needed css file and the descriptors which define our skin (trinidad-config.xml and trinidad-skins.xml).

We open the sharedskin.css file if it’s not open already and switch to source mode. Here we add two simple skin selectors

which are changing the color of the text of a button and a link. You can add more sophisticated selectors but for this blog, it’s enough to show the working skin. To make it more interesting, and because that’s the real reason for this blog, we add some images to the skin which we like to use in the application using the skin. We add the images into a new folder like shown below

The reason for this structure is, that to read the images from the jar in the consuming application, we need a special resource loader. In case of ADF it’s the resource servlet which listens to the URL pattern ‘/adf/’’. This servlet is installed automatically for ADF Web Applications and is configured in the web.xml file

The final task for the skin project is to create a jar file which we can use in other applications. The easiest way to get such a jar is to create an ADF Library deployment descriptor. Open the project properties of the skin project and select the ‘Deployment’ node

And click the ‘New Profile’ icon, select to create an ADF Library Jar

and click ‘OK’. The remaining dialogs you can just click ‘OK’ or ‘Finish’.

To create the library we have to execute the descriptor by right-clicking on the project and selecting ‘Deploy’ and choosing the ‘sharedskinadflib’

This will create the jar in the ‘deploy’ folder of the project.

Sharing the skin with other applications

To share the skin with other application we can

  1. Create an ADF Library
    1. Add this library to the other application
    2. Add this library as a shared library to a WebLogic Server
  2. Create a normal jar
    1. Add this library to the other application
    2. Add this library as a shared library to a WebLogic Server

For this blog, we want to use option 2b. This allows to create the skin once, deploy it to a server and use it in every other application. In the next paragraph, we try out option 1a to show the problems when reading resources from a jar file.

Using a shared skin

Option 1a

We start with option 1a, just to show the problem when we try to read a resource from a jar. We build another ADF Fusion Web application and add the skin as ADF library from a ‘File System Connection’ which we create and let it point to the ‘deploy’ folder

Right-click on the ‘sharedskinadflib’ and add it to the new sample project. This will make the skin available to the application. To use the skin we have to add a skin to the application like we did to create the skin project. The difference is that we now choose the shared skin as the base skin

Creating a new page and adding a button and/or a link to the page we see the new style introduced by the ‘sharedskin’

So, the shared skin is working. Well, yes, but what about the images we added to the ‘sharedskin’?

Let’s try to add one to the button. In the property editor, we select the icon property of the button and click ‘Edit’ to get

However, we don’t see any image in the whole project. As we know where we put the images (or we can look into the sharedskinadflib) we can just add the path to the image like ‘skins/sharedskin/adf/images/home.png’ and we see the image

Running the application we get the page with the button but don’t see the image

Using DeveloperTools we see that the resource couldn’t be found. Inspecting the button element we see

The path to the image is not found 😦

If we change the address of the image to ‘/adf/images/home.png’ to use the resource servlet we still get an error

The reason is that the resource servlet expects the resources in a different path inside the jar. Every resource which should be read from a jar should be in a folder named ‘META-INF’.

The ADF library did not put the images into the META-INF folder

The problem is that we can’t change the layout of the ADF Library. When you create an ADF Library there is no option to make any changes to the content of the jar.

The conclusion is that using a skin in an ADF Library is problematic if there are other resources which you need to share.

To be continued…

In the final part 2 of the series, we see how the skin can be shared with other applications.

Problems running JDeveloper 12c

In the last couple of weeks, I get more and more reports of problems running JDeveloper 12.2.1.x. (to be exact 12.2.1.1.0, 12.2.1.2.0 and 12.2.1.3.0)

The problems reported are

  • properties editor not working
  • JDeveloper hangs during start
  • showing wireframe instead of page design
  • problems to configure the JDBC connection
  • problems compiling expression on attributes (not 100% verified that this is JDK problem)
  • problems migrating projects created with earlier versions of JDeveloper
  • problems with the groovy script engine
  • deadlocks within JDeveloper when editing multiple java files

to name some. The problems are not ADF related but IDE related. It turned out that they only could be reproduced if the used JDK to run JDeveloper on was newer than JDK 1.8.0_101. All problems are not reproducible when running JDeveloper with JDK 1.8.0_101.

Currently, there is a bug pending (Bug 26766333) with support.oracle.com for some but not all mentioned issues. At the moment of writing this, there is no patch available.

My recommendation is to install JDK 1.8.0_101 and run JDeveloper using this JDK. You can do this by

  1. installing JDK 1.8.0_101 on your machine. The download for this old version is hard to find in the WWW. To make it easier, you can find it on this page: Java SE 8 Archive Downloads
  2. change the product.conf file you’ll find in your .jdeveloper folder inside your home folder. Open the file and set the SetJavaHome property
  3. to be on the safe side, you can recreate the integrated WLS to make it use JDK 1.8.0_101 too. If you know our way in the jungle of script files which are used to start the embedded WLS, you can change those files directly. As there typically are not many changes made on the integrated WLS, I find it easier to delete the integrated WLS and create it again. It’ll pick up the JDK JDeveloper is running on automatically and use it to run the WLS too.

You don’t need to update or change the JDK your standalone server is running on. To my knowledge, the problems are only IDE related, so they don’t affect the running application.

If you find a problem, which is related to using a JDK newer than 1.8.0_101, feel free to leave a comment on this post. I’ll add them to the list for reference.

JDev 12c: Debug Application Module Tester (BC4JTester) Problems

When you develop ADF Web Application you often use the ADF ApplicationModule Tester (BC4J Tester) to quickly test your business components data model and your self-written code in any EntityObject, ViewObject or ApplicationModule. For more information about how to do this look at JDeveloper & ADF: Use the Application Module Tester (BC4J Tester) to Test all your BusinessLogic.

Users who use one of the latest JDeveloper versions 12.2.1.1.0 and newer may have noticed, that the BC4J Tester application starts without an error, but doesn’t show the dialog. I run into this a couple of times lately and decided to dig into this problem. On the Oracle Development Spaces, I saw some threads about this too.

The reason for this behavior is that any EO, VO or other methods in the application module have an error, which can’t be found during compile time.

Use case

To show the effect, we start with a simple Workspace and a model project which only has one ViewObject in the Application Module’s data model

We implement a small use case where we want to see the total salary of all rows retrieved by the query behind the VO. Without any added where clause we get the total salary of all employees. If we add a filter e.g. by DepartmentId=90 we only get the total salary of all employees of department 90. Here are some images of the final running model in the BC4J Tester

Implementation

OK, so how do implement this use case?

We do this by adding a transient attribute to the EmployeesView and use a SQL default expression to do the calculation

sum(Employee.SALARY) OVER (PARTITION BY NULL ORDER BY NULL)

In the image below we see the definition of the transient attribute in the ViewObject

Problem

This should do the trick. However, when we try to test this in the BC4J Tester we get

In the log window, but no dialog where we see the application module. We don’t get any hint about what went wrong. The tester is up and running, but we don’t see anything.

Shay Shmeltzer mentioned in one of the ODC threads, that the reason for this is that there is an error in the application module (ViewObject, EntityObject or AM method). As the only thing we added is the SQL statement for the transient attribute, it’s clear that the statement must have an error. It’s simply a missing ‘s’ character, as the DB table we use is named ‘Employees’ and not ‘Employee’. So the correct statement is

sum(Employees.SALARY) OVER (PARTITION BY NULL ORDER BY NULL)

This will solve this problem and the BC4J Tester will start up and show (see the images above). But what if we added more things to multiple objects?

How to find the error then?

Older versions of JDev, the BC4J Tester did show an error message which showed the error and made solving the problem easy. Here is an image of the same application running using JDev 12.1.3.0.0

Solution

I did not manage to get the same output using JDev 12.2.1.1.0 or newer, but you can get the same message in the message window.

For this, you need to start the BC4J Tester with the java option

-Djbo.debugoutput=console

The option is added in the model projects ‘Run/Debug’ option in the project’s properties

Whenever you start the BC4J Tester and don’t get any dialog, you can assume that there is an error in the application module. To find out what the problem is, add the java option to the model project and you get the detailed information in the log window.

Train Stop Status Handling

A question on the Oracle Developers Community was about how to handle a train stops visited status.

Use Case

The use case behind this was that a train can be used as a workflow visualization. A normal user starts the train, but at one point a manager has to approve something. This approval is one or more stops on the same train. If the manager picks up the workflow he should automatically start with the approval stop. There is no need for him to see the data accumulated in the stops before.

The use case has multiple challenges:

  1. Securing train stops for different user roles
  2. Allow starting the train from any stop
  3. Handling the state of the train stops

The first two challenges are handler by All Aboard, 97. How-to defer train-stop navigation for custom form validation or other developer interaction, and 82. How to programmatically navigate ADF trains.

The missing part is how to handle the train stops ‘visited’ state (see image above). If you start the train directly with ‘Stop 3’ you get this state

UI

To implement this use case, we use a simple UI. It contains an input field, a button and the train which is added to the page as a region.

In the input field names label 1 you can enter the stop where the train should start. If no number is given, the train starts with the first stop. We use this input field to mimic the different starting stop for different users. This is the page when we start the application:

This is the page when we start the final application:

You can navigate between the train stops by using the ‘Back’ and ‘Next’ button, or by clicking the next stop in the train bar. As the stops are set to sequential, you can’t directly click on the 4th stop. You have to go through the stops 1 to 3 first.

Enter a number between 1 and 5 into the input field and tab out of the field will set the parameter for the train task flow and restart the task flow. The navigation is done via a router in the task flow. In the image below the stop number 3 is set as the starting stop for the train

And as you see the stops 1 and 2 are looking like they have visited before.

Implementation

To show how to implement this we start with a simple bounded task flow which builds the train

The start builds a router which we use to navigate to the stop where we want to start the train. The starting stop is passed as parameter to the task flow

In the router, which is marked as default activity, the parameter is used to execute the navigation

The Magic

If you look at the train stop properties in the properties inspector you’ll notice, that there is no property for the visited state

This option is not available in the UI. Oracle has missed or deliberately missed to make this property accessible via the properties. If you dig into the implementation of the train task flow (see the articles provided at the begin of the blog), you’ll see how to access the train and its stops by code:

ViewPortContext currentViewPortCtx = controllerContext.getCurrentViewPort();
TaskFlowContext taskFlowCtx = currentViewPortCtx.getTaskFlowContext();
TaskFlowTrainModel taskFlowTrainModel = taskFlowCtx.getTaskFlowTrainModel();
// get the stop from the map
TaskFlowTrainStopModel currentStop = taskFlowTrainModel.getCurrentStop();

The TaskFlowTrainStopModel doesn’t provide any access to the visited state. If you look at the class definition you’ll notice, that it’s only an interface

which doesn’t provide access to the visited property. Setting a breakpoint in the debugger we can inspect an instance of this interface

and we get the class implementing the interface as:

 oracle.adfinternal.controller.train.TrainStopModel

This class has the visited property we are looking for.

Solution

Now we can implement a method which we call before a train stop gets rendered and which sets the visited property of all previous stops to true.

CAUTION

THIS IN AN INTERNAL CLASS WHICH YOU SHOULD NOT USE!

However, it’s the class we need to get to the property. You have to understand, that the usage of the class has its risks, but that it’s not forbidden. The risk is that Oracle can change or delete the class without notifying you beforehand. So, in later versions, your code might break.

The method checks the task flow parameter if it’s null to set to a number less or equal to 0. In this case, the method returns an empty string. We do this check to avoid that the method does it’s work every time we navigate the train. It should be done only once when the train starts.

If the check finds a positive number, it sets the task flow parameter to zero (line 37).

It then gets the task flow information from the Context (lines 39-43). In line 50 we acquire the current stop before we loop over all previous stops and set their visited property to true (lines 53-59).

The missing part is how to call this method when a train stop is rendered. For this, we use a technique called Lazy Initalizing Beans. The trick is to use a hidden af:outputText and set e.g. the value property of the component to a bean property.

When the page or fragment is rendered, the method getInitStatus() in the bean is called. This is exactly the method shown above. We add this hidden af:outputText to each train stop before the af:train component.

Sample

You can download the sample from GitHub BlogTrainStopStatus. The sample is build using JDev 12.2.1.3 and doesn’t need a DB connection. You can use the same technique in other JDeveloper versions.

Query and Filter an af:listView

Most of the time we use tables to show tabular data to users. However, JDev and ADF allow for other components like the af:listView to be used to show such data to the user in a more modern way.

The image above shows the normal display of data when an af:query is used together with a table to show the result.

A more fancy, modern look we get if we use a af:listView to show the results as this allows us to style the data

Use case 1

We like to use an af:query to search for employees and show the result in a styled af:listView.

Implementation 1

This is pretty easy as we only have to use an af:listView as the result component of the af:query

And to exchange the af:table with an af:listView. Or you build the page by first dropping an af:query onto the page (without table) and then add the af:listView

Then you get the wizard to layout the list

This will give you a basic layout which can be styles in JDev as

The final result is

which looks more modern. One thing the af:table give you out of the box is the second use case.

User Case 2

We like the af:listView to be able to be filter the result like the af:table can.

Implementation of second use case

Easy you think? Well, the af:listView component doesn’t provide any filter out of the box. There isn’t even a filterModel like there is for an af:table.

So, how do we get this implemented. The idea is to use a af:table component but only use the filter provided by the af:table. The remaining parts like table data, possible scroll bars and status bar or scrollbars we remove.

We start by dragging the EmployeesView1 from the data control onto the page again.

And drop it after the closing af:panelHeader and before the af:listView as ‘ADF Table’

In the image you see that I have removed some available columns. Before we go to hide the part of the table we don’t need, we make the table work together with the af:query and the af:listView. When we use the af:query the table shows the right detail (auto PPR triggers the refresh of the table). However, if you have queried for the ‘Purchasing’ department and then enter an ‘s’ into the ‘First Name’ filter field of the table and hit enter, you get

As you see, the table shows the right result (2 rows) but the listView still shows all employees of the Purchasing department.

To make it work, we need to add a partialTrigger to the listView which points to the table. This way each time the table changes the listView will too.

Save all changes and refresh the page. Now if you enter a value into a filter field and hit enter, the listView will update too.

After the page works we have to get rid of the data below the header of the table. This is easy to accomplish by styling the table. We only need the filter field and the header below the filter fields so that we know which field filters which data. Simply set the maxHeight of the table to the exact height of the the two components. You can use your browser’s developer tools (F12) to measure the height. In my sample it’s 65px. So, setting the tables inlinestyle to

max-height: 65px;

will hide everything below the filter and the header

If you like you can create a skin and create a style class and use this style class instead of setting the max-height directly to the inlineStyle of the table. A nice addon is that the table header sorting is working too for the listView.

You can download the sample from gitHub BlogFilterListView. The sample is build using JDev 12.2.1.3 and uses the HR DB schema. The principle can be used in other JDev versions too.