Create drop down menu in seam with s:selectItems

Question

Hi guys, I have just started to learn seam framework. I decided to code two drop down menus. One listing categories and other listing subcategory. The idea is that user will first select a category and depending on that a subcategory will be populated.

<h:selectOneMenu value="#{manager.category}" required="true">
          <a:support event="onfocus" ajaxSingle="true" action="#{manager.dothis()}"/>
          <s:selectItems value="#{manager.categories}" var="cat" label="#{cat.categoryDescription}" noSelectionLabel="Select a Category"/>
          <s:convertEntity />

Above, I am trying to call dothis() method on event focus but its not working.

What am I doing wrong here?

Thanks.

Answer 1

1. Is your #{manager.categories} already populated?
2. What does #{manager.dothis()} do?

You probably don't want to do anything onfocus() ...unless maybe you're lazy loading the initial values (which I don't think you are). You should also be reRendering something in the <a:support> tag otherwise your action won't affect anything on your page.

Here's my approach to these (assumes #{manager.categories} is populated):

<h:selectOneMenu id="category" value="#{manager.category}" required="true">
          <a:support event="onchange" ajaxSingle="true" action="#{manager.populateSubCategories()}" reRender="subcategory"/>
          <s:selectItems value="#{manager.categories}" var="cat" label="#{cat.categoryDescription}" noSelectionLabel="Select a Category"/>
          <s:convertEntity />
</h:selectOneMenu>

<h:selectOneMenu id="subcategory" value="#{manager.subcategory}" required="true">
          <s:selectItems value="#{manager.subcategories}" var="subcat" label="#{subcat.categoryDescription}" noSelectionLabel="Select a Sub-Category"/>
          <s:convertEntity />
</h:selectOneMenu>