Passing parameter to completeMethod of p:autoComplete - jsf

Question

I'm using the PrimeFaces p:autoComplete widget in a search form of my project. The user can choose how many and which form-elements (search parameters) he wants to include so I need to pass an ID to the completeMethod for each of them. I've tried adding onfocus=".." to pass the object to the bean but that only would be activated when the element first is loaded.
My question: How can I pass an attribute to the completeMethod?
XHTML of the element (simple):
<p:autoComplete value="#{filter.value}" label="dynamic search attribute"
completeMethod="#{myBean.complete}" />
The bean (simple):
#Named("myBean")
public class MyController implements Serializable {
public List<String> complete(String query) {
List<String> results = new ArrayList<String>();
// ... code
return results;
}
}
In theory this would seem like the perfect solution:
<p:autoComplete value="#{filter.value}" label="dynamic search attribute"
completeMethod="#{myBean.complete(filter)}" />
And again the bean:
#Named("myBean")
public class MyController implements Serializable {
public List<String> complete(String query, FilterObject o) {
List<String> results = new ArrayList<String>();
// ... database query based on FilterObject o
return results;
}
}

Answer 1

You can set it as an attribute:
<p:autoComplete value="#{filter.value}" label="dynamic search attribute" completeMethod="#{myBean.complete}">
<f:attribute name="filter" value="#{filter}" />
</p:autoComplete>
and get it by UIComponent#getCurrentComponent():
public List<String> complete(String query) {
FacesContext context = FacesContext.getCurrentInstance();
FilterObject o = (FilterObject) UIComponent.getCurrentComponent(context).getAttributes().get("filter");
// ...
}
Alternatively, as that #{filter} appears in your case to be already in the EL scope, you can also leave the <f:attribute> away and get it by evaluating the EL expression programmatically with help of Application#evaluateExpressionGet():
public List<String> complete(String query) {
FacesContext context = FacesContext.getCurrentInstance();
FilterObject o = context.getApplication().evaluateExpressionGet(context, "#{filter}", FilterObject.class);
// ...
}
Or, if it is also a #Named bean, then you can just #Inject it in the parent bean:
#Inject
private FilterObject o;