Sunday, May 4, 2008

ADF Faces Rich Client - Complex Validation

Hey, my first application with JDeveloper 11g TP4 ! :-)

During this week I was working on business rules implementation design in my project. I got one really not usual business rule for UI, the thing is that client is Oracle Forms customer. So, in general this business rule was defined like - "When validation for particular field is failed, user must be not allowed to move to other fields". If you have noticed, in ADF Faces RC by default users are allowed to move focus to other fields and enter data, even if validation for some field is failed.

I was trying to use direct DOM manipulation to implement this rule, but without success. I have discussed this with Frank Nimphius (Principal Product Manager in Oracle) and he suggested working solution based on ADF Faces client framework. Actually I will document it in this blog post. Also you can read ADF Faces Rich Client - JavaScript Programming Nuggets page from Frank Nimphius blog.

I have implemented described business rule in sample application. Mandatory validation rules are applied for 3 fields - Last Name, Email and Job. Field - Job, contains LOV component and is associated with description text field - Job Title. And finally, application contains one optional Number type field. Sample is based on HR schema.

As you have noticed, there are 3 cases for validation in developed application - Mandatory, Mandatory LOV and Number type. You can easily implement your own rules, if will follow described techniques. Let's describe complex validation implementation steps for all 3 cases.

JavaScript code in all three cases will be written in af:group section created in af:document metaContainer facet:

1. Mandatory field

Rule description: When value is set to NULL and Tab button is pressed or mouse cursor is moved, focus must be returned back to Mandatory field where validation fails. To lock focus, JavaScript function is used, where ADF Faces client framework method is invoked:

Logically thinking, this function must be invoked when user is trying to move focus from current field with failed validation. With ADF Faces RC you can use af:clientListener operation component.

This component allows to invoke JavaScript function based on event. In our case, JavaScript function will be invoked when component loses focus - on blur:

At runtime, if value for mandatory Last Name field is removed:

Focus will be locked for Last Name field:

User will not be able to change values in other fields or press any buttons available on the page. The same applies for Email field.

2. Mandatory LOV field

Rule description: When value is set to NULL and Tab button is pressed or mouse cursor is moved, focus must be returned back to Mandatory LOV field where validation fails. Description text field associated with LOV field must be cleared, when validation in LOV field fails. In this case, I have used af:serverListener operation component additionally:

af:clientListener is defined similar like in previous case:

For af:serverListener I have provided its name in Type field and have specified method name from Backing bean. handlerMethod() is a Java method and this method will be invoked from JavaScript function in order to set empty value for description text field:

JavaScript function code:

Java method code:

Value of description text field in this sample application is binded to a method in backing bean:

Method in Backing bean provides value for description text field according to a value set from handlerMethod():

At runtime, when user clears value in mandatory LOV field:

Focus will be locked for this mandatory LOV field and associated description text field will be cleared. And of course, validation error message is displayed:

If you don't know already, nice feature of LOV component is that LOV window is opening automatically when wrong value is entered and Tab button is pressed (when AutoSubmit=True):

Tab button is pressed and LOV window is opened, since non existing value was entered originally:

When correct value is selected, associated description text field is refreshed again and user can move focus to other fields:

3. Number type field

Rule description: Focus is locked, when invalid value is entered. This rule is implemented in similar way as a rule in first case. JavaScript function is different:

When wrong value is entered, focus is locked again and validation error message is shown:


Anonymous said...

How to use this combination client/server listener on page load to call java method?

I tried it but it doesn't work when you put client listener type "load".


Andrej Baranovskij said...


You want to invoke Java method from JavaScript on page load? May be its better to do this from Backing bean and not from JavaScript?


Anonymous said...

How to do this? How to make java method which will be called before all other methods from backing bean?

Andrej Baranovskij said...


You can find solution in my previous blog post - Security in Oracle ADF and Automatic Page Loading.


Anonymous said...

I have a button that calls a method in my application module. This method sets conditions to load an iterator.
I want to load in some text fields te attributes from the interator row loaded AFTER y clic the button. I tried to do this using clientListener attached to the button, but I don't know how to call a backing method from javaScript. Is there any way to do this? Thanks in advance,

Andrej Baranovskij said...


Yes sure - you can use af:serverListener together with af:clientListener. I'm also using it my sample to call method in backing bean. Here you can read more - ADF Faces RC - How-to use the Client and Server Listener Component.


Javix said...

Hi Andrejus,

I have two inputText,how to make the focus of the first pass to the second box?
I work with fragment pages (.jsff) where to put the javascript code?

Joe D G said...

very nice solution. I approached it differently - enabled/disabled downstream fields based on valid values needed no JS - but yours is nicer.
However, it appears your solution cannot handle this use case (which I think is a bug):

1. enter value into LOV field, press tab, LOV pops up.
2. Click Cancel, dismissing LOV - press tab again, you can now tab to next field with an invalid value remaining in the field.
I get around this with my disabling the down stream fields. Can tab - but nowhere to tab to.

Argument can be made that if user clicks Cancel button on LOV they are *choosing* not to validate at this moment but wait until submit (when invalid value is caught via EO validation in List query).

Joe D G said...

Have logged a bug on this and seen it is fixed in the 11.1.2 release:
An invalid valid value in an LOV field will highlight in red and not let you tab out.

Andrej Baranovskij said...

Thanks for follow up ;)


Abhishek said...

Hi, How to add validation for max length of characters to be entered in rich text editor in ADF?