How to pass data from one Managed Bean to another? [duplicate] - primefaces

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Creating master-detail pages for entities, how to link them and which bean scope to choose
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Closed 4 years ago.
I am developing a website using JSF 2.2 and Primefaces 6.1 where I have, initially, 2 pages: A "list" page, where I can show the data to the user, and a "create" page, where I can create new data or edit existing ones.
NOTE: "Cargo" means occupation.
list.xhtml:
...
<h:form>
<p:commandButton value="Cadastrar" styleClass="ui-button-sucesso" action="create.xhtml?faces-redirect=true"/>
</h:form>
...
<h:form>
<p:dataTable value="#{cargoListMB.listaCargo}" var="cargo" rowKey="#{cargo.codigo}" emptyMessage="Nenhum cargo encontrado" filteredValue="#{cargoListMB.listaCargoFiltro}">
<f:facet name="header">Tabela de Cargos</f:facet>
<p:column headerText="Código" sortBy="#{cargo.codigo}" filterBy="#{cargo.codigo}" filterPosition="top">
<h:outputText value="#{cargo.codigo}"/>
</p:column>
<p:column headerText="Nome" sortBy="#{cargo.nome}" filterBy="#{cargo.nome}" filterPosition="top" filterMatchMode="contains">
<h:outputText value="#{cargo.nome}"/>
</p:column>
<p:column headerText="Funcionários" sortBy="#{cargo.funcionariosNesteCargo}"filterBy="#{cargo.funcionariosNesteCargo}" filterPosition="top">
<h:outputText value="#{cargo.funcionariosNesteCargo}"/>
</p:column>
<p:column headerText="Editar">
<p:commandButton icon="fa fa-pencil" title="Editar" styleClass="ui-button-icone-apenas" action="create.xhtml?faces-redirect=true">
<f:param name="objcargo" value="#{cargo.codigo}"/>
</p:commandButton>
</p:column>
</p:dataTable>
</h:form>
CargoListMB.java:
#ManagedBean(name = "cargoListMB")
#ViewScoped
public class CargoListMB implements Serializable {
private List<Cargo> listaCargo;
private List<Cargo> listaCargoFiltro;
public List<Cargo> getListaCargo() {
if (listaCargo == null) {
listaCargo = CargoDAO.listarTodos(); //load data from database
}
return listaCargo;
}
public void setListaCargo(List<Cargo> listaCargo) {
this.listaCargo = listaCargo;
}
...
}
create.xhtml:
<h:form>
<f:metadata>
<f:viewParam name="objcargo" value="#{cargoCreateMB.cargo}" converter="cargoConverter"/>
<f:viewAction action="#{cargoCreateMB.inicializar()}"/>
</f:metadata>
<div class="ui-grid ui-grid-responsive">
<div class="ui-grid-row">
<div class="ui-grid-col-6">
<h1 class="if-page-title"><h:outputText value="#{cargoCreateMB.cargo.codigo == 0? 'Cadastro de Cargos' : 'Edição de cargo'}"/></h1>
</div>
<div class="ui-grid-col-6"></div>
</div>
<br/>
<div class="ui-grid-row">
<div class="ui-grid-col-12">
<div class="ui-grid-row">
<div class="ui-grid-col-1">
<p:outputLabel for="nome" value="Nome:"/>
</div>
<div class="ui-grid-col-3">
<p:inputText id="nome" placeholder="nome" value="#{cargoCreateMB.cargo.nome}" required="true""/>
</div>
<div class="ui-grid-col-8">
<p:message for="nome"/>
</div>
</div>
<br/>
<div class="ui-grid-row">
<div class="ui-grid-col-3">
<p:commandButton value="Salvar" actionListener="#{cargoCreateMB.salvar}" update="form" styleClass="ui-button-salvar"/>
</div>
<div class="ui-grid-col-9"></div>
</div>
</div>
</div>
</div>
</h:form>
CargoCreateMB.java
#ManagedBean(name = "cargoCreateMB")
#ViewScoped
public class CargoCreateMB implements Serializable {
private Cargo cargo;
public void salvar() {
try {
ControleCargo.insereCargo(cargo); //saves the 'occupation' on the database
MensagensUtil.mensagemInfo("Atenção", "Cargo inserido com sucesso");
} catch (RuntimeException e) {
MensagensUtil.mensagemInfo("Erro", "Erro ao inserir cargo");
System.out.println("Erro: " + e);
}
}
public void inicializar() {
//QUESTION!! : Due to a JSF page's life cycle, could I put this code on the constructor??
if (this.cargo == null) {
this.limpar();
}
}
private void limpar() {
cargo = new Cargo();
}
public Cargo getCargo() {
return cargo;
}
public void setCargo(Cargo cargo) {
this.cargo = cargo;
}
}
As you can see, I am trying to pass the selected 'occupation' from page list.xhtml to crate.xhtml using <f:param> and <f:viewParam> tags. When I click on button 'Cadastrar' (means 'register'), everything works fine (the "cargo" object is initially null, as expected), but when I click on the edit button, the "cargo.codigo" (occupation's ID) value, sent by the <f:param> tag, does not "arrive" to the "cargo" object. The converter ('cargoConverter') should be working fine, BUT, when I checked the String value that the method getAsObject was receiving, it was ALWAYS "0", no matter which occupation I choose on my list.
I also tried to send the "raw" data: Instead of using a converter, I sent the "cargo.codigo" value directly to a String field, but it was ALWAYS null.
Could someone help me discover what was my mistake? Also, if it is possible, is there another way to send data to other Managed Beans? Thanks in advance.
Edit: Based on Kukeltje's comments, I formatted my code (which can be seen above) and removed all the nested <h:form> elements BUT the problem still persists. Therefore, the answers on question How to use <h:form> in JSF page? didn't help at all and this question is not a duplicate.

Answer 1

Based on Kukeltje's comments and tips and the answers on this question, I managed to find my mistake: my <f:metadata> was indeed inside a <h:form>
tag. I removed it from there and it worked perfectly.