You'll need an Extension that taps into the structure_index_view_data hook:
function activate_extension() {
$hooks = array(
"structure_index_view_data" => "customise_structure"
);
foreach ($hooks as $hook => $method) {
$data = array(
'class' => __CLASS__,
'method' => $method,
'hook' => $hook,
'settings' => "",
'priority' => 10,
'version' => $this->version,
'enabled' => 'y'
);
$this->EE->db->insert($this->EE->db->dbprefix . 'extensions', $data);
}//### End of foreach ###
}//### End of activate_extension function
Then in your customise_structure method:
function customise_structure($data) {
if ($this->extensions->end_script === TRUE)
return $data;
if ($this->EE->extensions->last_call !== FALSE)
$data = $this->EE->extensions->last_call;
foreach($data["data"] as $tab_id => $content) {
foreach($content as $eid => $page) {
//Use $page['entry_id'] to get the entry ID
//Use $page['title'] to append and customise the row display
...
}//### End of foreach ###
}//### End of foreach ###
return $data;
}//### End of customise_structure function
Using the entry_id you could run a query for each loop getting the custom field then appending it to $page["title"] with relevant spacing or span to indent or style further.
Be warned though, do a query per loop would be consuming, you'd be better to do an initial loop building the entry_id list, then build a single SQL getting just the single custom field you require for all the entries.
This should be enough to get you up and running on building your own extension.
