Joomla XML form display user information?

[waltsjt]

Coding Question: How do you display user information in an Joomla xml form after selecting the user via the field type type="user"
I've looked at a lot of tutorials but nothing seems to broach this subject.

Basic concept I'm working on is to select the user and show the user name and email in the form:

Code: Select all

<?xml version="1.0" encoding="utf-8"?>
<form>
	<fieldset>
		<field name="user_id" type="user"       
    	            label="COM_MYCOMPONENT_FORM_LBL_USER_USER_ID"
	            description="COM_MYCOMPONENT_FORM_DESC_USER_USER_ID" 
                    required="true"  /> 
		<field name="username" type="text"
    	            label="COM_MYCOMPONENT_FORM_LBL_USER_USER_NAME"
	            description="COM_MYCOMPONENT_FORM_DESC_USER_USER_NAME"
	            />
                <field name="user_email" type="text"
    	            label="COM_MYCOMPONENT_FORM_LBL_USER_USER_EMAIL"
	            description="COM_MYCOMPONENT_FORM_DESC_USER_USER_EMAIL"
	            />
	</fieldset>
</form>

What modifications are needed to have the form dynamically show the selected user's information in the form?

Thanks for your help and guidance in this topic.