Export records with HABTM

[dineshvasudev]

How can I export records associated with HABTM?

When I tried to export with help of csvview, it exports only one value but not all the associated values.

I have research programs containing various departments, I want to export the filtered search results as csv.

 $this->loadModel('Researchprograms');
 $this->loadModel('Departments');
 $researchprograms = $this->Researchprograms->find('search', $this->Researchprograms->filterParams($this->request->query)) ->contain(['Users', 'Departments']);

foreach ($researchprograms as $researchprogram):
    $data = [$researchprogram];
endforeach; 

$_serialize = ['data'];
$this->response->download('my_file.csv');
$this->viewBuilder()->className('CsvView.Csv');
$this->set(compact('data','_serialize'));  

This code generates csv file but every record has only one departments, but there are many departments for a record.

Let me know how can I export the records with all associated departments (HABTM)?

[ADmad]

Use a callable in $_extract variable to format the departments list as required. For e.g.

$_extract = [
    // other fields
    'departments' => function ($row) {
        return implode(',', Hash::extract($row, 'departments.{n}.name'))
    }
];