title: Why are primefaces-Tags highlighted as error in IntelliJ?
body: <p>I have xhtml-files in my spring-project. In IntelliJ it suggests me some imports like <code>xmlns:h="http://java.sun.com/jsf/html"</code> when I use primefaces-Tags. But when I agree the import the URI is also highlighted as ERROR with message "URI is not registered".</p>
  
  <p>Below a snippet from a xhtml-file:</p>
  
  <pre><code>  &lt;p:column headerText="Username"
            &lt;h:outputText value="#{user.username}"/&gt;
    &lt;/p:column&gt;
  </code></pre>
  
  <p><code>&lt;p&gt;</code> and <code>&lt;h&gt;</code> are highlighted in colors, but in <code>&lt;p:column&gt;</code> or <code>&lt;h:outputText&gt;</code> the string after the colon is always highlighted as ERROR with message, e.g. "cannot resolve symbol h:outputText".</p>
  
  <p>The strange thing is, the project compiles with no errors. But in IntelliJ the whole xhtml-files are full of "errors". It's quite annoying when looking for an error and all the lines are RED.</p>
  
  <p>I've already tried to "Invalidate cache/restart".</p>
  
  <p>Hope someone can help me solving this problem?</p>