OK, so I have managed to get this working - though I am not sure if it is the best way to do it - or if there are security issues in using a blank form as the loginFormTpl in the header.
1. I found a phx statement on the phx custom modifiers wiki (
http://wiki.modxcms.com/index.php/PHx/CustomModifiers) that checks if a web user is loggd in - so I created a new snippet and called it "phx:webuserloggedin":
<?php
global $modx;
$condition[] = intval(isset ($_SESSION['webValidated']));
?>
2. Then I created a new webloginPE call as a chunk called "wlpe login hdr" for the header (which excludes the option to login as I only want the success message displayed in the header):
[!WebLoginPE? id=`wlpe-Hd` &type=`simple` &loHomeId=`40` &loginFormTpl=`wlpe-loginFormTplHdr` &successTpl=`wlpe-successTpl` &messageTpl=`wlpe-messageTpl` &disableServices=`login,profile,saveprofilesimple,deleteprofilesimple,confirmdeleteprofilesimple,registernew,register,forgot,resetpassword,activate,activated` !]
3. Then I created a new webloginPE loginFormTpl chunk called "wlpe-loginFormTplHdr" for the header (which is a blank form) - I am not sure if this is the right way to do it:
[+wlpe.message+]
<div id="wlpeLogin" class="login">
<form class="loginForm" id="wlpeLoginForm" action="[~[*id*]~]" method="POST">
</form>
</div>
4. Then I create a new chunk called "wlpe phx hdr" containing the phx "webuserloggedin" statement:
[+phx:webuserloggedin:then=`{{wlpe login hdr}}`:else=``+]
5. Then I include the "wlpe phx hdr" chunk into the page’s logo header:
6. Then I updated the CSS to hide the webloginPE message in the header on page 40 (as I only want to display the form / message in the rhs column on page 40):
body#bd40 #hdbox #loggedin { display: none; }
Any thoughts?