How to pass a parameter along with h:commandButton
jsf, jsf-2, parameter-passing, seam
Solution
Either pass as method argument (only if your environment supports EL 2.2),
<h:commandButton value="English" action="#{localeSelector.change('en')}" />
<h:commandButton value="Deutsch" action="#{localeSelector.change('de')}" />
<h:commandButton value="Français" action="#{localeSelector.change('fr')}" />
with
public void change(String language) {
locale = new Locale(language);
// ...
}
Or use `<f:setPropertyActionListener>`
<h:commandButton value="English" action="#{localeSelector.change}">
<f:setPropertyActionListener target="#{localeSelector.language}" value="en" />
</h:commandButton>
<h:commandButton value="Deutsch" action="#{localeSelector.change}">
<f:setPropertyActionListener target="#{localeSelector.language}" value="de" />
</h:commandButton>
<h:commandButton value="Français" action="#{localeSelector.change}">
<f:setPropertyActionListener target="#{localeSelector.language}" value="fr" />
</h:commandButton>
with
private String language;
public void change() {
locale = new Locale(language);
// ...
}
Or use `<f:param>`
<h:commandButton value="English" action="#{localeSelector.change}">
<f:param name="language" value="en" />
</h:commandButton>
<h:commandButton value="Deutsch" action="#{localeSelector.change}">
<f:param name="language" value="de" />
</h:commandButton>
<h:commandButton value="Français" action="#{localeSelector.change}">
<f:param name="language" value="fr" />
</h:commandButton>
with
public void change() {
locale = new Locale(FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get("language"));
// ...
}
(you can also let JSF automatically set it by a `@ManagedProperty("#{param.language}")`, but this requires the bean to be request scoped, or a `<f:viewParam>`, see also ViewParam vs @ManagedProperty(value = "#{param.id}"))
Enough ways to pass a parameter from view to controller. Take your pick. The `<h:inputHidden>` serves in JSF context a somewhat different purpose and it can only be manipulated by JavaScript in the `onclick` which is ugly.
Problem
One of the most common approaches to change locale in JSF+Seam - with `<h:selectOneMenu>`: ``` <h:form action="#{localeSelector.select}" rendered="false"> <h:selectOneMenu value="#{localeSelector.language}" onchange="submit()"> <f:selectItem itemLabel="English" itemValue="en" /> <f:selectItem itemLabel="Francais" itemValue="fr" /> </h:selectOneMenu> </h:form> ``` I want to implement locale changes with buttons. So, the question is - how to pass the parameter (en, fr, etc.) to update the bean with `<h:commandButton>`? Maybe `<h:inputHidden>` would help?