JDeveloper: Using Task Flow Parameters to Show Different UI in a Region

Lately a couple of questions on the JDeveloper & ADF space regarding using task flow parameters came up.

Use Case

One specific use case was how to show different UI in the same region if a row is just created or if the user wants to edit an already existing row.

Full description is that the user sees a table with e.g. regions of the HR DB schema. Now there are two buttons, one ‘Create new…’ and one ‘Edit current…’. When clicking the ‘Edit current…’ button the currently selected row of the table should be loaded into a form. There the user can edit everything but the primary key (PK). If the user click the ‘Create new…’ button the same form should be visible, but the PK should be editable too.

Running Application

To make it more visible let’s start with the finished application:

selection_955

Running Application

The final UI looks like in the image above. The UI is composed of four areas as in the image below:

selection_955_comment

The ‘Header’ and ‘Search Panel’ area are only for convenience. In the ‘Panel Collection Bar’ holds a toolbar with two buttons ‘Create new…’ and ‘Edit current…’. The table below shows the result of a search of the Region table from the HR DB.

Selecting a row in the table we can edit the selected record by clicking on the ‘Edit current…’ button

selection_956

This will open a new screen showing the selected row. Above the ‘RegionId’ we see a text indicating that we are in ‘edit’ mode and we can’t edit the ‘RegionId’ attribute as it’s the PK of the row and should not be editable.

Here we can edit the RegionName attribute and store the change by clicking the ‘Commit’ button:

Likewise, if we click the ‘Create new…’ button we go to the same form, but this time the text above the ‘RegionId’ attribute tells us that we are in ‘create’ mode and we can edit the RegionId.

Committing the changes we get a new row in the Regions HR DB table.

Implementation

Ok, let’s talk about how to implement this. For the model layer we run the ‘Business Components from Table…’ wizard on the model project and select the regions table from the HR DB. For this demo this is all we need to do.

The UI consist of two pages, index.jsf and Region.jsf. The index.jsf page is the start page and shows the UI as in the first image. Everything is easily done by drag and drop the right components in the right order onto the page. I spare the details for this as you can look at the sample which you can download using the link at the end of the post.

The only thing I like to go into detail is the toolbar with the two buttons ‘Create new…’ and ‘Edit current…’. These buttons do two things:

  1. Set a mode property to pageFlowScope
  2. Navigate to the second page Region.jsf

The Toolbar definition looks like

 <af:toolbar id="t1">
   <af:button text="Create new..." id="b1" action="show">
     <af:setPropertyListener from="#{'create'}" to="#{pageFlowScope.mode}" type="action"/>
   </af:button>
   <af:button text="Edit current..." id="b2" action="show">
     <af:setPropertyListener from="#{'edit'}" to="#{pageFlowScope.mode}" type="action"/>
   </af:button>
 </af:toolbar>

The create button has a af:setPropertyListener added which sets a pageFlowScope attribute ‘mode’ to ‘create’ and navigates to the Region.jsf page by executing the ‘show’ navigation from the unbounded task flow adfc-config.xml

adfc-config.xml

adfc-config.xml

The edit button uses an af:setPropertyListener which sets a pageFlowScope attribute ‘mode’ to ‘edit’ and then executes the navigation ‘show’ to go to the Region.jsf page. The logic to insert a new row or to edit an existing row is done in the bounded task flow ‘region-edit-create-btf.xml’ which we talk about later.

The Region.jsf page consists of a Header and a Region holding an af:form of the selected row of the Region:

selection_957_comment

Region.jsf

The region itself is a bounded task flow with the following properties

selection_964

Here we see one parameter with the name ‘mode’ which stores its value in a pageFlowScope attribute named ‘mode’. One other thing we need to make sure of is that the region shares the data control with its parent (in this case the adfc-config unbounded task flow) and always begins a new transaction. This make the bounded task flow a unit of work, it encapsulates the work in the task flow. The interface of the bounded task flow describes what the unit of work does:

Interface of ‘region-edit-create-btf.xml’ task flow:

If mode is set to ‘edit’, the current selected row of the Region table is shown in a form and can be edited. 

If the mode is set to ‘create’, a new row is created and inserted into the Region table and can then be edited.

The user can commit or cancel the operation. After each of this operations the task flow executes a parent action ‘back’.

selection_965

We see that the default action of the task flow is a router which uses the parameter set to the task flow to execute the create of the edit navigation:

selection_966

after that the now current record is shown on the fragment (see the area marked ‘Region’ in image Region.jsf). Below we see the panelFormLayout used for the region:

 <af:panelFormLayout id="pfl1">
   <af:outputText value="we are in #{pageFlowScope.mode eq 'create'? 'create' : 'edit'} mode" id="ot1"/>
   <af:inputText value="#{bindings.RegionId.inputValue}" label="#{bindings.RegionId.hints.label}"
     required="#{bindings.RegionId.hints.mandatory}" columns="#{bindings.RegionId.hints.displayWidth}"
     maximumLength="#{bindings.RegionId.hints.precision}" shortDesc="#{bindings.RegionId.hints.tooltip}" id="it1"
     disabled="#{pageFlowScope.mode ne 'create'}">
     <f:validator binding="#{bindings.RegionId.validator}"/>
     <af:convertNumber groupingUsed="false" pattern="#{bindings.RegionId.format}"/>
   </af:inputText>
   <af:inputText value="#{bindings.RegionName.inputValue}" label="#{bindings.RegionName.hints.label}"
     required="#{bindings.RegionName.hints.mandatory}" columns="#{bindings.RegionName.hints.displayWidth}"
     maximumLength="#{bindings.RegionName.hints.precision}" shortDesc="#{bindings.RegionName.hints.tooltip}" id="it2">
     <f:validator binding="#{bindings.RegionName.validator}"/>
   </af:inputText>
   <f:facet name="footer">
     <af:panelGroupLayout id="pgl2">
       <af:button text="Commit" id="b2" action="commit"/>
       <af:button text="Rollback" id="b1" immediate="true" action="rollback">
         <af:resetActionListener/>
       </af:button>
     </af:panelGroupLayout>
   </f:facet>
 </af:panelFormLayout>

Let’s look at the actions which are done in the region. If the user commits the changes the commit action from the data control is called which saves the changes to the db. If the ‘cancel’ button is clicked, the rollback method from the data control is called which reverts any changes done in the task flow. After the commit or rollback a parentAction (paraneAction1) is called which executes the ‘back’ navigation in the adfc-config.xml which navigates back to the index.jsf page.

Please note that we could have added the calls to commit and rollback to the buttons in the region.jsff. I decided to put them into the task flow instead to show the whole task flow and how it works in one place.

Implement different UI according to the task flow parameter

So, how do we use the parameter passed to the bounded task flow to switch the UI?

This is done by using an expression language (EL) which points to the ‘mode’ attribute stored in the pageFlowScope. Sample: the text above the RegionId is created with an af:outputText like

<af:outputText value="we are in #{pageFlowScope.mode eq 'create'? 'create' : 'edit'} mode" id="ot1"/>

The EL ‘#{pageFlowScope.mode eq ‘create’? ‘create’ : ‘edit’} ‘ is used to differentiate between the modes. Likewise the disable property of the RegionId attribute uses the EL

...disabled="#{pageFlowScope.mode ne 'create'}"...

which is true when the passed parameter is not ‘create’. In this case the disabled property is set to false, meaning that the field can’t be edited.

That’s it. There is no line of java code necessary to implement this use case.

Download

You can download the sample which was build using JDeveloper 12.2.1.2 and uses the HR DB schema from GitHub BlogTaskFlowParameter.

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JDev 12.1.3: Using Parent Action to Navigate Tabs of a af:panelTabbed from Inside a Region

This blog is based on a question in the OTN JDeveloper and ADF forum. The Question was how to navigate from one selected tab to the next tab when the af:showDetailItem in the tab is a region and the button to navigate is inside the region.

We implement two cases, the first is the easy one where the button to navigate is in the page holding the af:panelTabbed. The second one uses a button is inside a bounded task flow which is shown in the af:showDetailItem in a tab to navigate the af:panelTabbed.

We start with creating a new ‘ADF Fusion Web Application’ from the gallery. We only change the application name and the path of the application, otherwise we can just use the default values. The sample is simple and doesn’t need a model project or connection to a DB. You can download the finished workspace using the link provided at the end of the post.

We skip all the needed steps and going right into creating the starting page which holds the af:panelTabbed. It has three af:showDetailItem and a af:Button to navigate the tabs directly from the page. This button implements the first use case.

Start Page with Outer Navigation

Start Page with Outer Navigation

The button has a listener attached which is implemented in a viewScope bean ‘NavigateTabBean’. The listener implements the needed logic to navigate from the selected tab to the next tab. If the last tab is reached the first tab is selected.

    private static ADFLogger _logger = ADFLogger.createADFLogger(NavigateTabBean.class);
    private static final String PANELTAB = &quot;pt1&quot;;

    /**
     * Eventhandler to navigate to the next tab in a af:panelTabbed
     * @param actionEvent event which called the listener
     */
    public void naviGateButtonAction(ActionEvent actionEvent) {
        UIComponent ui = getUIComponent(PANELTAB);
        if (ui == null) {
            _logger.info(&quot;PanelTab component not found!&quot;);
            return;
        }
        if (!(ui instanceof RichPanelTabbed)) {
            _logger.info(&quot;Component is not an af:panelTabbed&quot;);
            return;
        }

        RichPanelTabbed rpt = (RichPanelTabbed) ui;
        int childCount = rpt.getChildCount();
        List&lt;UIComponent&gt; children = rpt.getChildren();
        for (int ii = 0; ii &lt; childCount; ii++) {
            UIComponent uiSDI = children.get(ii);
            if (uiSDI instanceof RichShowDetailItem) {
                RichShowDetailItem rsdi = (RichShowDetailItem) uiSDI;
                if (rsdi.isDisclosed()) {
                    //close current tab
                    rsdi.setDisclosed(false);
                    //calculate next tab to disclose as next_tab_index = (current_tab_index + 1) % number_of_tabs
                    int kk = ii + 1;
                    int jj = kk % childCount;
                    _logger.info(&quot;old disclosed tab: &quot; + ii + &quot; new disclodes tab: &quot; + jj);
                    RichShowDetailItem newSDI = (RichShowDetailItem) children.get(jj);
                    //open new tab
                    newSDI.setDisclosed(true);
                    AdfFacesContext.getCurrentInstance().addPartialTarget(rpt);
                    return;
                }
            }
        }
    }

    // find a jsf component
    private UIComponent getUIComponent(String name) {
        FacesContext facesCtx = FacesContext.getCurrentInstance();
        return facesCtx.getViewRoot().findComponent(name);
    }

    public void nextTab() {
        naviGateButtonAction(null);
    }

The logic in the action listener first searches for the af:panelTabbed in the viewRoot and gets the number of children from it. Each child is one of the af:showDetailItem representing a tab. Then we iterate over the child list and search the currently disclosed tab. We close this tab and the next tab in the list gets disclosed. If the currently selected tab is the last in the list, the first tab is disclosed (see the comments in the code section).

To Implement the second use case, the one we really want to talk about, we first need to implement three bounded task flows which we later use as regions in the tabs.

Bounden Task Flow with Parent Action

Bounden Task Flow with Parent Action

The image shows the bounded task flow for one tab. The other bounded task flows are build in the same way and are just showing different text. The reason for this is that you normally would use different regions aka different task flows in the tabs. We could have used only one bounded task flow with a parameter to change the text shown in the fragment. In the sample you’ll find this implemented for tabs 4 and 5.
The region is simple and only shows one fragment which has a button to navigate to the next tab and a test to distinguish the regions when navigating. The whole magic is the parent action in the bounded task flow. This parent action executes a navigation case ‘nextTab’ in the parent task flow.

Unbounded Task Flow with Start Page

Unbounded Task Flow with Start Page

In the image above we the the unbounded task flow which is the parent of the bounded task flow. Here a wild card rule navigates to a method call activity ‘selectNextTab’ using the navigation case ‘nextTab’ we entered to the parent action of the regions.
The method action calls the ‘nextTab()’ in the managed bean from the code section above. All this method does is to call the action listener which is called from the af:Button of the start page (Start.jsf). As the action listener needs an ActionEvent as parameter, which we don’t use in the code we pass ‘null’ when we call the listener from the method call activity.

This concludes the implementation. Here are some images from the running application

The sample application can be downloaded form ADFEMG Sample Project.

A version of the software build with JDeveloper 11.1.1.7.0 can be downloaded from GitHub

JDev 12.1.3: Use Default Activity Instead of the Deprecated Invoke Action

Since JDeveloper 12.1.3 the invoke action used in earlier version has been deprecated. Users still using the old invoke action to load data on page load should migrate their code to using the default activity in a bounded task flow instead. This article describes how to use the executeWithParams method as a default activity in a bounded task flow (btf) to load data to be shown in a region. For this we implement a common

Use Case:
in a text field the user enters a string which should be used to look-up data in the DB and show the data as a table in a region.
For this we use the HR schema and build a look-up for locations after the name of the city of the location. In a page the user can insert the name or part of a cities name into a text field. This input is send as parameter to a bounded task flow. The default activity of the btf calls a method in the view object which uses a view criteria to search for cities starting with the given input data. In a second implementation the same technique is used but a where clause is used in the VO and the VO is called with executeWithParams. The result of the search is displayed as a table in a region.

Implementation

Model Project:
We start by creating a new ‘Fusion Web Application’ and creating a model project of the HR DB schema. Here we only use the location table for which we create entity object and view object.
Now we create the view criteria which we use to find locations by part of the city name.

Next step is to create the java class for the view object including the method to safely access the created bind variable. In the class we add a method to apply the created view criteria which we expose in the client interface well as the methods to access bind variables.


Finally we have to make sure that the locations view object is part of the data model of the application module.
Resulting Application Module Data Model

Resulting Application Module Data Model


Next we add another view object to the data model which we use to implement the use case a second time. This time we use the view criteria we defined in the view object LocationsView and select it as the default where clause.

ViewController Project:
We start implementing the view controller project by first adding a start page, ‘Start’, to the unbounded task flow in adfc-config.xml. For this page we use a quick layout (One Column, Header stretched).

After opening the page (which creates it) we add a third grid row to the panelGridLayout we got from the quick layout which later holds the result table. In the first grid row we add a captain for the page, ‘Execute with param sample’, the second grid row we add an af:inputText which holds the users input for the city name to search for.
The page looks like

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE html>
<f:view xmlns:f="http://java.sun.com/jsf/core" xmlns:af="http://xmlns.oracle.com/adf/faces/rich">
    <af:document title="Start.jsf" id="d1">
        <af:form id="f1">
            <af:panelGridLayout id="pgl1">
                <af:gridRow height="50px" id="gr1">
                    <af:gridCell width="100%" halign="stretch" valign="stretch" id="gc1">
                        <!-- Header -->
                        <af:outputText value="ExecuteWithParams Test" id="ot1" inlineStyle="font-size:x-large;"/>
                    </af:gridCell>
                </af:gridRow>
                <af:gridRow height="50px" id="gr2">
                    <af:gridCell width="100%" halign="stretch" valign="stretch" id="gc2">
                        <!-- Content -->
                        <af:inputText label="City" id="it1" value="" autoSubmit="true"/>
                    </af:gridCell>
                </af:gridRow>
                <af:gridRow id="gr3">
                    <af:gridCell id="gc3">
                        <!-- REGION HERE -->
                    </af:gridCell>
                </af:gridRow>
            </af:panelGridLayout>
        </af:form>
    </af:document>
</f:view>

Now we create a pageDefinition for the page, where we define a variable and an attribute binding which holds the users input into the inputText we added to a grid row below the header.


The final inputText look like

<af:inputText label="City" id="it1" value="#{bindings.searchCityName1.inputValue}" autoSubmit="true"/>

As you see we set the autoSubmit property to true as we don’t have (and need) a button to submit the data to the binding layer.

The next task is to create a new bounded task flow which has one input parameter, which is used to search for locations with cities starting with the given parameter from the inputText component.

Once the bounded task flow is created we can drag this btf onto the start page and drop it in the girdCell in the third gridRow and wire the parameter for the task flow to the value we have stored in the in the variable iterator via the inputText.

Finally we make the region refresh whenever the inputParamter of the task flow changes by setting the regions refresh property to ‘ifNeeded’.
The final ‘Start’ page layout looks like

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE html>
<f:view xmlns:f="http://java.sun.com/jsf/core" xmlns:af="http://xmlns.oracle.com/adf/faces/rich">
    <af:document title="Start.jsf" id="d1">
        <af:form id="f1">
            <af:panelGridLayout id="pgl1">
                <af:gridRow height="50px" id="gr1">
                    <af:gridCell width="100%" halign="stretch" valign="stretch" id="gc1">
                        <!-- Header -->
                        <af:outputText value="ExecuteWithParams Test" id="ot1" inlineStyle="font-size:x-large;"/>
                    </af:gridCell>
                </af:gridRow>
                <af:gridRow height="50px" id="gr2">
                    <af:gridCell width="100%" halign="stretch" valign="stretch" id="gc2">
                        <!-- Content -->
                        <af:inputText label="City" id="it1" value="#{bindings.searchCityName1.inputValue}" autoSubmit="true"/>
                    </af:gridCell>
                </af:gridRow>
                <af:gridRow id="gr3">
                    <af:gridCell id="gc3">
                        <af:region value="#{bindings.showlocatiobycitybtf1.regionModel}" id="r1"/>
                    </af:gridCell>
                </af:gridRow>
            </af:panelGridLayout>
        </af:form>
    </af:document>
</f:view>

This concludes the first implementation and we can run the application

The sample application can be downloaded form ADFEMG Sample Project. It contains a second page (Start2) which uses the other view object (LocationsWithParamsView) inside the region. It’s build like the first version. The difference is that the default activity nor is the executeWithParams from the VOs operations instead the self implemented method from the VO. You spare writing the method and exposing the method in the client interface this way.
Be aware that the sample uses the HR DB schema and you have to change the connection information to point to your DB.

Book Review: Oracle ADF Faces Cookbook by Amr Gawish

During my short vacation I spend some time reading books. One of them was ‘Oracle ADF Faces Cookbook’ by Amr Gawish (http://bit.ly/PhWTlR).

Oracle ADF Faces Cookbook

Oracle ADF Faces Cookbook


The book is written as a cookbook, as the name says, for ADF Faces in the version 12c (12.1.2.0.0 to be accurate). The book offers 10 chapters:

  1. Building Your ADF Faces Environment From the Ground Up
  2. Here you get information about how to install JDK 1.7, Oracle XE Database, JDeveloper and how to tune the environment to work best together. Finally you can download the code used throughout the book from a GIT repository.Make sure to download the code and have it ready while reading the book!

  3. Getting Started with ADF Faces and JDeveloper
  4. In this chapter you get the very basics about development of Fusion Web Applications, building an workspace, connection to the DB, creating a business service, defining page flows and pages and how to run an ADF Faces application from within JDev.

  5. Presenting Data Using ADF Faces
  6. Here we start with use cases used for presenting data. You get info on how to present single records and different master – detail use cases, using different techniques. Finally a first glance on internationalization.

  7. Using Common ADF Faces Components
  8. Here you get a walk through to the normal adf faces components for input, output, selection, loading of data as well as pop-up, code editor, menu model, links, trains and dynamic components.

  9. Beautifying the Application Layout for Great User Experience
  10. Is about page templates, skins, responsive design and flat design techniques.

  11. Enriching User Experience with Visualization Components
  12. This chapter handles maps, graphs, gauges, Gantt charts, hierarchy, sunburst and timeline components.

  13. Handling Events and Partial Page Rendering
  14. Here events (client and server), partial triggers and behavior components are introduced. Polling, Drag & Drop, Active Data Service and WebSocket are described too in this chapter.

  15. Validating and Converting Inputs
  16. Is about conversation of data, custom converters, validation (client and server) and faces messaging.

  17. Building Your Application for Reuse
  18. Picking up from chapter 2 we learn about page templates, exception handling task flow parameters, contextual events, ADFLibraries and finally Meta Data Service (MDS).

  19. Scaling your ADF Faces Application
  20. The final chapter is about performance and recommendations as well as some advances options like Content Delivery Network (CDN) and ADF caching of resources.

The cookbook uses its own db schema which looks kind of familiar, as it’s build from the well known HR schema.

While reading the book I found some recipes hard to understand for novice developers, without reading the provided code in parallel. This is because the book is all about ADF Faces but spares most about the ADF Business Components Model layer. Here the reader has to know how things are working and how to set things up.
For experienced developers some of the covered topics are nothing new, we work with them every day. The uses cases covered are mostly basic in nature and you often see links to the original documentation. Here you find the missing information which is not covered in the cookbook itself. I would have liked some more deep going information on how properties work together for some often used components like af:table or af:panelGridLayout.

I personally found it hard to understand why the author used task flows build from pages for some of the use cases just because ‘it’s easier’. One of the main advantages are task flows build of fragments. They allow reuse and help divide a task into smaller pieces. Tools like the ADF-EMG Task Flow Tester are not even mentioned. Using this tool makes it easy to run task-flows build on fragments without the need to build a JSF Page to host the region.
There are no use cases which handle region specific questions like when regions are refreshed or how regions are restarted. Transaction management and data control sharing are not covers too.

The real interesting part of the book starts with chapter 5, where page templates, skins and at least some layout techniques are introduced. Very interesting is the use case about using SAAS (Syntactically Awesome Style Sheets) and Compass to build more dynamic css files which can be used in ADF. The chapter covers Responsive Web Design and Flat Design Techniques (which are trying to minimize the design) too.

Also interesting are the samples which are build in chapter 6 for graphs, gauges, maps, pivot table, Gantt charts (calendar is missing), timeline and sunburst. However I personally find them hard to digest as they have many ingredients (steps in this case) which you have to follow. Again the model layer is pre-build for you, which means you have to find out yourself how and if there are something special in the model to cook the dish. Nevertheless, samples in this area are hard to find, and these samples do work!

The chapter about event handling and ppr is a very nice summary of how things work in ADF. Easy to understand samples are making it easy to follow the concepts. Here you find samples for ADS (Active Data Service) and WebSocket too. Nice!
Contextual events are handled in a later chapter (‘Building Your Application for Reuse’) but they are not described in great detail. It’s enough to get a first impression.

The final chapter is a nice summary of performance increasing methods and techniques which is worth reading. After reading the techniques it make sense to test them on your system!

Summary:
Novice developers learn basic ADF Faces techniques and components by building samples. Some recipes are too complicated to understand by just reading them. As the book uses its own DB schema you should have this ready, as well as the code, to work through them.

Using one ViewObject for Global Lookup Data (Part 2)

Based on the other post ‘Using one ViewObject for Global Lookup Data’ I got an other question on how to use this approach in a way, that a LOV is initalized with an area of lookup data before the page in shown to the user.
This can be done, all declarative without the need to write java code e.g. in an onLoad() method. The solution is to use a bounded task flow which initializes the LOV before navigation to the page the LOV is used.
To show this we create a simple navigation model in the adfc-config.xml like

Navigation Model

Navigation Model

‘Generic Lookup’ is used to show how to do this inside a page, where the lookup is presented in a region, the ‘LookupInitPosition’ shows how to preset an area for the lookup data (POSITION in this case) before showing the page in a region too.
Before we go into detail on how to setup the UI we need to add another view object to our data model which we use the acquire the lookup data

VO to get Lookup Data

VO to get Lookup Data


The ‘GeneralLookup’ view object is the same we used in part 1 to get the lookup data of an area, only this time we don’t specify lookup area but a dummy value (‘1’ in this case) for the area. This dummy value is set so that we don’t get any result back. If the ‘GeneralLookup’ view is executed without an area given from the outside, we don’t get any result. Keep this in mind when we are looking at the running sample later on.

Back to the UI. As both use cases uses a region it’s a nice sample how a bounded task flow (btf) can be reused in different use cases. The bounded task flow itself looks like

Navigation Model Bounded Task Flow

Navigation Model Model Bounded Task Flow

Bounded Task Flow to Show preselected Lookup Data

Bounded Task Flow to Show preselected Lookup Data


As you see the bounded task flow uses a method call (ExecuteWithParams) as it’s start activity. A task flow parameter is used to pass the name of the lookup area we want the LOV to initially show.
The name of the input parameter does not really matter, what you have to note down is the value part ‘#{pageFlowScope.selectedType}’ as this is the the variable we use to set the bindType parameter of the method call activity ExecuteWithParams.

Setup of the ExecuteWithParams Method Call

Setup of the ExecuteWithParams Method Call

After executing the query with the new set bindType we navigate to to page to show the result:

Region View1 which shows the LOV with the Preselected Lookup Data

Region View1 which shows the LOV with the Preselected Lookup Data


We see the LOV as af:selectOneChoice which stores the selected value in an attribute from the variable iterator (see Creating Variables and Attribute Bindings to Store Values Temporarily in the PageDef for more info on this). The input text below the LOV can be used to change the area parameter used for the LOV. If we enter e.g. WEEKDAY and click the ‘Refesh’ button, the input value is read and transferred to the parameter (#{pageFlowScope.selectedType}) for the executeWithParameter method via a af:setPropertyListener. This allows to change the LOV on the fly from within the region.
The LOV source is a dynamic list generated from the Generallookup VO as seen in the next image
Setup LOV for af:selectOneChoice

Setup LOV for af:selectOneChoice

After we know how the region (the bounded task flow) works, we can build the GenericLookup.jspx page. This page allows to enter the name of an ares into an input text field and then to refresh the bounded task flow, which we put on the page as region.

The final use case is to navigate to a page with with a preselected lookup area, POSITION in this case. For this we use the button ‘goto Page with init on POSITION’ at the bottom of the page.

You can download the sample workspace which was build JDeveloper 11.1.1.7.0 and using the HR schema from the ADF EMG Samples side BlogStaticVOLov_V3.zip. You can open the workspace using JDev 11.1.1.6.0 without a problem. If you are asked if you like to migrate the workspace to 11.1.1.6.0 answer with Yes.

JDeveloper 11.1.1.5.0 : Use Router to Create New Row or Edit Existing

Based on a question on the OTN ADF forum I wrote a small sample to show how to use a router in a bounded task flow to either edit an existing row, or create a new row and present it to enter data.

Use Case
Based on a query which returns either zero or one row an edit form should should be presented to the user. This form show the data from the row found, or an empty form to allow creation of a new row.

Implementation
The sample workspace, which you can download from the ADF Samples webside using the link at the end of this post, uses a very simple model. It contains only one view object, based of the LOCATIONS table of the HR schema.
The view object has one custom method implemented which search for a location record by an id. This method is used as query which returns either one row (if the location is found) or no row (if the location is not found).
The UI is build with one page which has a splitter component. On the left facet we find an simple form which we use to input the location id to search for and a button to execute the query. To allow to save or cancel the actions we add a rollback and a commit button. On the second facet we see a region which shoes the panelForm to either edit the existing record or to enter data into a new created record.
The image below shows the page layout.

General page layout

General page layout

Running

The next image shows the running application with a location id found

Running application with Location Id found

Running application with Location Id found

and then with a location id not found

Location ID not found

Location ID not found

You clearly see the empty from to enter new row data.

Now, to implement this the first splitter facet has a button to executes the query (find location by id) with the id given in the inputText. The region on the second splitter facet refreshes itself as we set the ‘Refresh’ property to ‘ifNeeded’. To make this work we need to change an input parameter to the region. This is done by binding the input parameter of the region to the inputText component for the location id.

Setup of input parameter of the region

Setup of input parameter of the region

So whenever the input parameter changes the region gets restarted. this effect we use in the bounded task flow to check if we have to create a new row and thus show a empty form, or to just edit an existing row. For this the bounded task flow uses a router component as start activity. This router checks if the iterator of the locations view object contains zero rows or more.

Bounded task flow

Bounded task flow

The router uses the estimatedRowCount of the underlying view object in an expression to check the number of rows:

EL to check if iterator has zero rows

EL to check if iterator has zero rows

The router navigates to the ‘insert’ case if the EL evaluated to true, to the ‘edit’ case otherwise. That concludes the use case.

You can down load the sample work space from ADF Samples Repository. The sample was build using JDeveloper 11.1.1.5.0 but should work using 11.1.1.6.0 and 11.1.2.x too. It uses the HR schema and you need to correct the db credentials to run the sample.