Wednesday, October 19, 2011

ADF 11g : Query Component with ‘dynamic’ view criteria

In my current project use a lot of re usable taskflows. In one particular situation I needed exactly the same taskflow to be re-used with one tiny small difference: The displayed query component needed to have different fields compared to page in the base taskflow. Now there are lots of possible solutions (two query components and a switcher, or two query components using the rendered property). I choose a different solution using ternary operator and EL in the page definition.

Use case

I need to display a different query component when the taskflow is started in a specific mode. For instance I can startup the taskflow a being a HR manager, or I can startup the taskflow as being an employee. In the first case I need to be able to search on items like salary and commission and hiredate. In the second case I need to be able to search on firstname. lastname and more stuff like that, and I can only see employees in my own department.


Lets start with the creation of default business components for the Employee table. Next step is the creation of view criteria. I need two view criteria. The first one is called ManagerVC, the second on EmployeeVC.

With this in place I create a simple taskflow with a pagefragment. The taskflow has an inputParameter called 'startupMode'. The pagefragment contains a table with a query component. This is easy to create by dragging the Employees collection from the datacontrol onto the pagefragment and pick "query panel with table".

Make sure to have single row selection enabled.

I also create a testpage in order to run my taskflow. The testpage is a rather simple page containing two buttons, and a bean to hold the value of the button that is pushed.
 <af:toolbar id="t1">  
<af:commandToolbarButton text="Start as Manager" partialSubmit="true" id="ctb1">
<af:setPropertyListener from="mgr" to="#{TesterBean.buttonPushed}" type="action"/>
<af:commandToolbarButton text="Start as Employee" id="ctb2"partialSubmit="true">
<af:setPropertyListener from="emp" to="#{TesterBean.buttonPushed}" type="action"/>

I drop my taskflow on the page as a region. I link the inputparameter of the taskflow to the buttonPushed property. Don't forget to set the refresh option to 'ifNeeded', so the region will refresh whenever the input paramaters change.

When I run the page you will see the querycomponent as expected.

The trick:
Now take a look what happened when the query component was created. The page definition states contains an executable binding for the search region.
 <searchRegion Criteria="CriteriaForManager"  

This is exactly the place where I will use an EL expression (yes you can do that) to dynamically set the viewcriteria to be used by the query component. Lets change the "criteria" attribute. Whenever the taskflow is started by a manager I want the CriteriaForManager viewcriteria to be used by the querycomponent, and in other cases the CriteriaForEmployee.
 <searchRegion Criteria="#{pageFlowScope.startupMode eq 'mgr' ? 'CriteriaForManager' : 'CriteriaForEmployee'}"  

Now this is really all I changed. No changes to the page whatsoever. When I run the page after this minor change, depending on the startupmode, a different querycomponent is rendered. Or actually, the querycomponent stays the same, only the viewcriteria used are different.

This post was initially posted by me on the AMIS technology blog.
The workspace can be downloaded here.

Monday, October 03, 2011

ADF 11g Quicky 3 : Adding Error, Info and Warning messages

How can we add a message programatically ? Last week I got this question for the second time in a months time. I decided to write a short blogpost on how this works.

Adding messages is very easy, you just need to know how it works.
You can add a message to your faces context by creating a new FacesMessage. Set the severity (ERROR, WARNING, INFO or FATAL ), set the message text, and if nessecary a message detail. The fragment below shows the code for an ERROR message.

1:   public void setMessagesErr(ActionEvent actionEvent) {  
2: String msg = "This is a message";
3: AdfFacesContext adfFacesContext = null;
4: adfFacesContext = AdfFacesContext.getCurrentInstance();
5: FacesContext ctx = FacesContext.getCurrentInstance();
6: FacesMessage fm =
7: new FacesMessage(FacesMessage.SEVERITY_ERROR, msg, "");
8: ctx.addMessage(null, fm);
9: }

I created a simple page with a couple of buttons to show the result of setting the message. When the button is pressed the message is shown.
1:  <?xml version='1.0' encoding='UTF-8'?>  
2: <jsp:root xmlns:jsp="" version="2.1"
3: xmlns:af=""
4: xmlns:f="">
5: <af:inputText label="Label 1" id="it1"></af:inputText>
6: <af:inputText label="Label 2" id="it2"
7: binding="#{pageFlowScope.msgsBean.showMessage}"></af:inputText>
8: <af:inputText label="Label 3" id="it3"></af:inputText>
9: <af:commandButton text="error" id="cb1"
10: actionListener="#{pageFlowScope.msgsBean.setMessagesErr}"/>
11: <af:commandButton text="info" id="cb2"
12: actionListener="#{pageFlowScope.msgsBean.setMessagesInf}"/>
13: <af:commandButton text="warn" id="cb3"
14: 15: actionListener="#{pageFlowScope.msgsBean.setMessagesFat}"/>
16: <af:commandButton text="warn for comp" id="cb4"
17: actionListener="#{pageFlowScope.msgsBean.setMessagesWrnForComp}"/>
18: </jsp:root>

A special case is the message that is directly related to a component. For that I use the button that calls the "setMessageForComp" method combined with an inputtext field that is bound to a bean : binding="#{pageFlowScope.msgsBean.showMessage}.
The code behind this button is slightly different from the one show in the java fragment earlier. The important part is that the message is specifically added to the component : getShowMessage().getClientId(ctx).

1:   public void setMessagesWrnForComp(ActionEvent actionEvent) {  
2: // Add event code here...c
3: String msg = "This is a message";
4: AdfFacesContext adfFacesContext = null;
5: adfFacesContext = AdfFacesContext.getCurrentInstance();
6: FacesContext ctx = FacesContext.getCurrentInstance();
7: FacesMessage fm =
8: new FacesMessage(FacesMessage.SEVERITY_WARN, msg, "");
9: ctx.addMessage(getShowMessage().getClientId(ctx), fm);
10: }
11: public void setShowMessage(RichInputText showMessage) {
12: this.showMessage = showMessage;
13: }
14: public RichInputText getShowMessage() {
15: return showMessage;
16: }
17: public void setMessagesWrnForComp(ActionEvent actionEvent) {
18: // Add event code here...c
19: String msg = "This is a message";
20: AdfFacesContext adfFacesContext = null;
21: adfFacesContext = AdfFacesContext.getCurrentInstance();
22: FacesContext ctx = FacesContext.getCurrentInstance();
23: FacesMessage fm =
24: new FacesMessage(FacesMessage.SEVERITY_WARN, msg, "");
25: ctx.addMessage(getShowMessage().getClientId(ctx), fm);
26: }
27: public void setShowMessage(RichInputText showMessage) {
28: this.showMessage = showMessage;
29: }
30: public RichInputText getShowMessage() {
31: return showMessage;
32: }

The code for this quicky can be downloaded here.