Primefaces DefaultCommand buttons switch according to zone - primefaces

Question

As you can see i first look for a person with a first commandButton, then i select a person in the datatable and i have a second commandButton, and i'd like to switch the defaultCommand on button2 after i selected a person, how can i achieve this?
<h:form id="form"
rendered="#{security.asRole('ADMIN') or security.asRole('GESTIONNAIRE')}">
<f:event type="preRenderView" listener="#{paieAgentView.init()}" />
<p:fieldset legend="Recherche de l'agent">
<p:panelGrid columns="2">
<p:panelGrid columns="2" id="pgRechercheAgent">
<h:outputLabel value="Matricule :" />
<p:inputText id="matricule"
value="#{paieAgentView.agentSearched.matricule}">
<p:ajax process="matricule" partialSubmit="true" event="keyup" />
<h:commandButton id="boutonLigneAgent"
action="#{paieAgentView.searchLigneAgent()}"
value="Rechercher les agents" icon="ui-icon-search"
update="listAgents" immediate="true" >
<f:ajax render="#form" execute="#this" />
</h:commandButton>
<br />
</p:panelGrid>
<p:dataTable id="listAgents" var="agt"
value="#{paieAgentView.listLigneAgent}"
selection="#{paieAgentView.agentSelected}"
rowKey="#{agt.matricule}" style="margin-bottom:0"
selectionMode="single" scrollRows="20" scrollable="true"
liveScroll="true" scrollHeight="250">
<p:ajax event="rowSelect" update=":form:pgRechercheContrats" />
<p:column headerText="Matricule">
<h:outputText value="#{agt.matricule}" />
</p:column>
<p:column headerText="Nom">
<h:outputText value="#{agt.nomPat} #{agt.prenom}" />
</p:column>
</p:dataTable>
</p:panelGrid>
<p:defaultCommand target="boutonLigneAgent" />
</p:fieldset>
<p:fieldset legend="Critères de recherche">
<p:panelGrid columns="3" id="pgRechercheContrats">
<h:panelGrid columns="1" style="margin-bottom:10px" cellpadding="5">
<p:outputLabel for="typePeriode" value="Période de paie:" />
<p:selectOneRadio id="typePeriode"
value="#{paieAgentView.typePeriode}">
<f:selectItem itemLabel="Période de paie" itemValue="paie" />
<f:selectItem itemLabel="Période d'origine" itemValue="origine" />
</p:selectOneRadio>
</h:panelGrid>
<h:panelGrid columns="2" id="pgCalendar">
<h:outputLabel value="Date Debut : " for="calendrierDateDebut" />
<p:calendar id="calendrierDateDebut"
value="#{paieAgentView.dateDebut}" pattern="yyyy-MM-dd"
effect="slideDown" navigator="true" mode="inline"
locale="#{sessionControleur.langue}" style="moisAnSeul" />
<h:outputLabel value="Date fin : "
for="calendrierDateFin" />
<p:calendar id="calendrierDateFin"
value="#{paieAgentView.dateFin}" pattern="yyyy-MM-dd"
effect="slideDown" navigator="true" mode="inline" lang="fr"
locale="fr" style="moisAnSeul" />
</h:panelGrid>
<p:selectManyCheckbox id="gridTypesPaie"
value="#{paieAgentView.selectedTypesPaie}" columns="1"
layout="pageDirection">
<f:selectItems value="#{paieAgentView.typesPaie}" var="type"
itemLabel="#{type.label}" itemValue="#{type.value}" />
</p:selectManyCheckbox>
</p:panelGrid>
</p:fieldset>
<p:commandButton process="pgRechercheContrats"
icon="ui-icon-file-pdf" value="Editer les fiches de paie"
action="#{paieAgentView.printPaieAgent()}" update="#form"
escape="false" ajax="false"
onclick="regenererCal();this.form.target='_blank'" />
</h:form>

Answer 1

Make 2 defaultCommands both with rendered attribute. Rendered should check if person is selected or not and action called must be appropriete on that. since you are updating whole form every time something change this should work
<p:defaultCommand target="boutonLigneAgent" rendered="#{personIsSelected()}"/>
<p:defaultCommand target="pgRechercheContrats" rendered="#{personIsNotSelected()}"/>