Add custom select dropdown in magento grid

Question

I'm trying to add a custom dropdown with (select/options) in my magento grid but it doesn't work, I tried with

$this->addColumn('dropdown', array(
'header' => Mage::helper('catalog')->__('Dropdown'),
'filter'    => false,
'sortable'  => false,
'type'=> 'options',
'options' => array('First'=>'firstvalue', 'second' =>'secondvalue')
));

I'm not using value from database but from an API, at first I want to display this select dropdown on my grid but all I see is a blank space.
Thanks.

EDIT :

Actually what I need to do is the first row with the dropdown, and the second row is what i get with the code I provided.
I can add a link like the "view" column but it doesn't work for a dropdown

Answer 1

There is two ways of doing what you want:

First way:

$this->addColumn('dropdown', array(
    'header' => Mage::helper('catalog')->__('dropdown'),
    'filter'    => false,
    'sortable'  => false,
    'index' => 'stores',
    'type' => 'select',
    'values' => array('First'=>'firstvalue', 'second' =>'secondvalue')
));

So it will display directly on your grid

Second way:

$this->addColumn('dropdown', array(
    'header' => Mage::helper('catalog')->__('dropdown'),
    'filter'    => false,
    'sortable'  => false,
    'index' => 'stores',
    'renderer' => 'Module_ModuleName_Block_Adminhtml_Renderer_Dropdown',
));

Then you need to create a Dropdown.php file in Modulename\Block\Adminhtml\Renderer\ with :

<?php
class Module_Modulename_Block_Adminhtml_Renderer_Dropdown extends Mage_Adminhtml_Block_Widget_Grid_Column_Renderer_Abstract{

public function render(Varien_Object $row) {
    $html = '<select>';
    $html .= '<option value="First">First value</option>';
    $html .= '<option value="Second">Second value</option>';
    $html .= '</select>';
    return $html;
  }
}

You just have to replace Module, Modulename with yours and Dropdown with what you want.