How to process primefaces dialog - jsf-2

Question

I have a primefaces dialog and what I want to do is process inputtext before commandbutton action starts. Inside myController.sendToPostBox method, myController.rejectionReason string returns null. Here is my view code.When I remove process attribute, commandbutton doesn't works.
<h:form>
....
<p:dialog id="myPanel"
widgetVar="myPanelId"
resizable="true"
appendToBody="true"
draggable="true"
height="200"
width="300">
<p:panelGrid id="myPanelGridId" style="width: 250px;" styleClass="panelGridWithoutBorder">
<p:row>
<p:column colspan="2">
<p:inputTextarea style="width: 250px;" value="#{myController.rejectionReason}"/>
</p:column>
</p:row>
<p:row>
<p:column>
<p:commandButton value="Save"
oncomplete="if (!args.validationFailed) myPanel.hide();"
process="myPanelId"
action="#{myController.sendToPostBox()}"/>
</p:column>
<p:column>
<p:commandButton value="Close" />
</p:column>
</p:row>
</p:panelGrid>
</p:dialog>
</h:form>

Answer 1

Just place the <h:form> inside the dialog (instead dialog inside the <h:form>)
Explanation:
When you use appendToBody="true" you dialog is being transferred outside of the form that wraps it to the body of the generated html , and since there is no form inside the dialog you can't really submit it.
Also take a look at this thread: Proper Construct for Primefaces Dialog

Answer 2

You need something like this:
<h:form id="formDialog">
<p:commandButton id="basic" value="Basic Dialog" onclick="PF('dlg1').show();" type="button" />
</h:form>
<p:dialog id="basicDialog" header="Basic Dialog" widgetVar="dlg1">
<h:form id="formUser">
<h:panelGrid id="grid" columns="2">
<h:outputLabel value="Username:" />
<p:inputText id="user" value="#{user.name}" />
<h:outputLabel value="Password:" />
<p:inputText id="password" value="#{user.password}" />
<h:commandButton value="Login" id="btn" process="#formUser" actionListener="#{user.login}" />
</h:panelGrid>
</h:form>
</p:dialog>
"login" in the actionListener tag is a method in the User(bean) class, that needs the #ManagedBean annotations.