Tuesday, November 8, 2011

Validate Entity or Validate Entity Attribute when using af:table or af:treetable ? ADF BC 11g


With this post we are going to investigate which validation is better to use for a specific circumstance. The Entity Validation or the Entity Attribute Validation for the specific case of af:table UI component. Here is our case:

We have rows that have  two input fields that they depend on each other.
For instance, in this example we are going to use the HR schema of Oracle XE,  we are going to have a logic that says that we cannot have an employee with firstName or PhoneNbr. But we can have an employee without firstName and phone Nbr. In other words, we have to set values to both fields or to none of them.

Download Sample Application.

NOTE: This is an example test case and this example might not actually fit any business logic. It is purely illustrative and the scope of this post is to investigate a best practice on the validation approach of two depended fields.

So, what we have now is a business rule. This rule says that we can have an employee with no firstName and no phoneNbr, but, if we must set values, we have to set to both of them.

OK, for this rule we are going to develop both cases for our investigation.

One with Entity Attribute Validations. Method A

One with Entity Validation. Method B

For the simplicity of this example, we will create two separate entities of the employees table and two separate views.

Method A:

Since it is not just a mandatory property and has some logic, for this example we are going to use a method type of validation.

We accept the default name of the method, as proposed from JDeveloper wizard.

In the failure handling section we set a message that corresponds to our business logic:

We do exactly the same ( with a slight difference in the failure handling message) for the PhoneNbr attribute.

For the phoneNbr we have to check the the checkBox in order to generate the method. This is because there is already one method.

Next, we have to right some code in the methods:
NOTE: in case your java class has no accessors, go to the java section of your entity, press the pencil and select the Create Accessors checkBox

The methods for each attribute:

Method B:
For method B, we will do the same process but only once, with one method. Because we are going to create one EntityValidation method. We are using EntityB. The process is the same, but the starting point is different:

Now, we have only one method so we will simply put both conditions of the other entity class into this method:

All we have to do now, is to create two separate pages, each one will have a view Object (already created by the JDeveloper wizard ). All we have to do after the pages, is to... test...

We create the pages and we drag and drop a view to a page:

we set the FirstName and the PhoneNbr as autoSubmit true.

If you run the application and press the first button, we will be navigated to to method A page where we have the entity attribute validations. There, if go and delete the value of the FirstName in the first row, press tab, we will get an error message:

The above is correct. It is exactly what we wanted. Lets go and delete the PhoneNbr of the same row,
Normally, we should not get any error message right? At least, this is the visual logical thought..
However, we still get the error...

This is very logical and expected behavior. Since validations are failed, no values are set in the attributes, thus our method in the second attribute handles the FirstName with it's "old" value which is not old because it has never changed.

Now, if we check the same in the second page, we will not receive the same behavior. We will have the accepted one. The difference here is that the Entity Validation is triggered when the whole entity is submitted. This happened when we change a row by clicking to another record in the table or by pressing a button.

So this investigation and example clearly indicates that when it comes to depended attributes and their validations, the correct declarative way is to use an Entity Validation and not an Entity Attribute Validation


Download Sample Application.


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