title: Get string behind binding object
body: <p>I have the following JSF construct:</p>
  
  <pre><code>    &lt;c:set var="myVar" value="#{myBean.getMyMap()}" scope="request" /&gt;
      &lt;h:form&gt;
      &lt;p&gt;
          &lt;h:outputText value="Output1: " /&gt;
          &lt;h:selectOneMenu value="#{myMappingsBean.data.attribute1}" binding="#{input1}" required="true"&gt;
              &lt;f:selectItems var="entry" value="#{myVar}"/&gt;
              &lt;p:ajax update="myDropdown"/&gt;
          &lt;/h:selectOneMenu&gt;
      &lt;/p&gt;
      &lt;p&gt;
          &lt;h:outputText value="Output2: " /&gt;
          &lt;h:selectOneMenu id="myDropdown" value="#{myMappingsBean.data.attribute2}" binding="#{input2}" required="true" converter="javax.faces.Double"&gt;
              &lt;f:selectItems var="entry" value="#{myVar.get(input1.value)}"/&gt;
          &lt;/h:selectOneMenu&gt;
      &lt;/p&gt;
      &lt;/h:form&gt;
  </code></pre>
  
  <p>Behind myVar is a map defined like that: <code>Map&lt;String, Collection&lt;Double&gt;&gt;</code></p>
  
  <p>The first dropdown menu shows a list of all the keys of that map (like desired), but the value behind that is the collection of values.
  Here the HTML output of one option of that dropdown:</p>
  
  <pre><code>&lt;option value="[1.0, 2.0]"&gt;SomeString&lt;/option&gt;
  </code></pre>
  
  <p>My second dropdown should list the collection of double values stored in the map behind the key, that is selected by the first menu.
  <strong>The problem now is</strong>, when I use <code>value="#{myVar.get(input1.value)}"</code> the value I get from <code>.value</code> is the collection and not the string/key of the map. So I never get the desired result.
  How can I get the string/key behind the binded object <code>input1</code>? Is there something like <code>input1.name</code> or <code>.toString</code>? Is somewhere a documentary for this?</p>