Conditionally show dialog in action method - validation

Question

Well, I have a form with a lot of buttons, when user click on a button some method must be executed in ManagedBean, a "crazy" logic. So I have 2 solutions for that and i would like to know the suggetions of you:
First Solution
<p:commandButton actionListener="#{myBean.someMethod}" value="Execute method 1" process="#this" />
public void someMethod(ActionEvent event){
if (selectedCustomer){
myCrazyLogicHere();
RequestContext.getCurrentInstance().update("formAlternative:componentToUpdate");
RequestContext.getCurrentInstance().execute("someAlternativeDialog.show()");
}else{
addErrorMessage("Select a Customer before click on Method 1");
}
}
Second Solution
<p:commandButton actionListener="#{myBean.someMethod}" update=":formAlternative:componentToUpdate" oncomplete="someAlternativeDialog.show()" value="Execute Method 1" />
public void someMethod(ActionEvent event){
if (selectedCustomer){
myCrazyLogicHere();
}else{
addErrorMessage("Select a Customer before click on Method 1");
}
}
So, I have a problem in "Second Solution". When commandButton complete your cycle, it will execute "someAlternativeDialog.show()", I need put a condition to that, just show dialog if "selectedCustomer" is true. In "First Solution" this problem is already solved, because i'm doing all in ManagedBean, the JSF just call the method.
So, my doubt is : What is the best form to work ? If form 2 is better, how can i condition the dialog show ?

Answer 1

You shouldn't be performing validation in action method in first place. You should be performing validation using a true validator. E.g., using required="true"
<h:selectOneMenu value="#{myBean.selectedCustomer}" required="true"
requiredMessage="Select a Customer before click on Method 1">
...
</h:selectOneMenu>
When validation using a true validator fails, then JSF already won't invoke the command button's action. This way you can get rid of the whole if-else block and addErrorMessage() in action method. If validation fails, PrimeFaces will set an indicator args object with a validationFailed property which you can use in oncomplete:
<p:commandButton ... oncomplete="if (!args.validationFailed) someAlternativeDialog.show()" />