Ok, you can solve it like this:
You have already the view and stuff and are able to get default data.
What you can do next is to fork the form template (profile_form.php in your case I guess)
- Copy the profile_form.php into the tmpl folder of your fork folder.
- In the you will find <fieldset> stuff.
Manipulate like so:"
<fieldset class="fieldsform form-horizontal">
<?php
//check if this is a new item,
if ($this->model->getId() == 0) {
//get default data
$fieldSet['jform_field1']->jdomOptions = array(
'dataValue' => $default_value1
);
}
echo $this->renderFieldset($fieldSet);
?>
</fieldset>
In short: in the view the data is already populated, you need to save and get the default data in the form.
There might be a better way, but this will work