Expression Engine Module tables and datasort - codeigniter

Question

I am currently working on a custom module add-on and I wanted to be able to use sorting and filtering on the a table in my control panel admin. I am using the EE table class and form helper. I'm trying to follow the documentation here for setting it up, but when I call try to call the '_datasource' method in my class I get this error
Fatal error: Call to undefined method Content_publish::_datasource() in /home/public_html/system/expressionengine/libraries/EE_Table.php on line 162
I have a feeling it's a scoping issue, but in the table class '$this->EE->table->datasource()' method you are supposed to just pass a string value with the name of your datasource function which is what I'm doing.
I don't seem to be the only one with this issue. There are more details and code examples on this EE Discussion forum thread
The documentation is not really clear. I also tried looking at EE's own comments module to see if i could figure it out, but no luck. Anyone have experience with this?
Here is the method I'm calling:
$data = $this->EE->table->datasource('_datasource');
And this is my function in my class:
function _datasource()
{
// ....
// $query comes from DB result set code above.
// I have omitted it here for brevity
$datarows = array();
foreach ($query->result_array() as $key => $row)
{
$datarows[] = array(
'entry_id' => $row['entry_id'],
'date' => date('Y-m-d',$row['entry_date']),
'author' => $row['screen_name'],
'payment' => $payment_amount,
'status' => $status,
'title' => $edit_href.$row['title']."</a>"
);
}
return $datarows;
}

Answer 1

Your datasource callback function must be on your Module_mcp class (looking at your forum thread you are trying to use it on a plugin which would explain the error).
If you want to put the datasource method on a different class, then just add this line right before you call datasource() to trick the table library into using the correct class:
// ensure table callbacks use this class rather than our MCP file
$this->EE->_mcp_reference =& $this;
$data = $this->EE->table->datasource('_datasource');
The table and form_validation libraries are the only two which use the special _mcp_reference variable, so I can't see any side effects to changing it, and have successfully done this in at least two modules.
On a side note, if you want a good example of how to use the built in tablesorter, take a look at system/expressionengine/controllers/cp/members.php. The documentation is pretty bad, but the source code always tells the truth :)

Answer 2

I've been having issues too and have a mixed solution of generate() and datasource working. Here it is here:
In my mcp file:
public function index()
{
$this->EE->cp->set_variable('cp_page_title', lang('my_module_name'));
$data = $this->EE->table->datasource('_datasource');
return $this->EE->load->view('index', $data, TRUE);
}
public function _datasource()
{
$headers = array(
'name' => array('header' => 'Name'),
'color' => array('header' => 'Color'),
'size' => array('header' => 'Size')
);
$rows = array(
array('name' => 'Fred', 'color' => 'Blue', 'size' => 'Small'),
array('name' => 'Mary', 'color' => 'Red', 'size' => 'Large'),
array('name' => 'John', 'color' => 'Green', 'size' => 'Medium'),
);
return array(
'rows' => $rows,
'headers' => $headers
);
}
In my index view file:
$this->table->set_columns($headers);
$this->table->set_data($rows);
echo $this->table->generate();
Seems to be working at the moment and I've not tried pagination yet, but sorting works.