Add wysiwyg editor in Magento Custom Module

Considering custom module Bd_Demo

Add following function in Bd_Demo_Block_Adminhtml_Demo_Edit

protected function _prepareLayout() {
    parent::_prepareLayout();
    if (Mage::getSingleton('cms/wysiwyg_config')->isEnabled()) {
        $this->getLayout()->getBlock('head')->setCanLoadTinyMce(true);
    }
}

Then use as in grid from  Bd_Demo_Block_Adminhtml_Demo_Edit_Tab_Form
$fieldset->addField("wood_description", "editor", array(
"label" => Mage::helper("woodflooring")->__("Description"),
"class" => "required-entry",
"required" => true,
"name" => "wood_description",
'config'    => Mage::getSingleton('cms/wysiwyg_config')->getConfig(),
'wysiwyg'   => true,
));

MAgento : Add custom action to Sales Order Grid

Here we use an event core_block_abstract_prepare_layout_before
1. Add following script in config.xml
<events>
<core_block_abstract_prepare_layout_before>
        <observers>
                <bdaction_block_abstract_prepare_layout_before>
                        <type>singleton</type>
                        <class>Bd_Test_Model_Observer</class>
                        <method>addMassCustomAction</method>
                </bdaction_block_abstract_prepare_layout_before>
        </observers>
</core_block_abstract_prepare_layout_before>
</events>
2.Create a observer class like Bd_Test_Model_Observer
then add a method
public static function addMassCustomAction($observer)
{
    $block = $observer->getEvent()->getBlock();
    if(get_class($block) =='Mage_Adminhtml_Block_Widget_Grid_Massaction'
        && $block->getRequest()->getControllerName() == 'sales_order')
    {
        $block->addItem('customaction', array(
        'label' => 'Custom Action',
        'url' => Mage::helper('adminhtml')->getUrl('module/controller/action'),
        ));
    }
}
3.At last create that controller and action method

Magento : add massDelete action in coupon code

First override Mage_Adminhtml_Block_Promo_Quote_Grid class and add following code
protected function _prepareMassaction()
    {
        $this->setMassactionIdField('rule_id');
        $this->getMassactionBlock()->setFormFieldName('rule');

        $this->getMassactionBlock()->addItem('delete', array(
             'label'    => Mage::helper('rule')->__('Delete'),
             'url'      => $this->getUrl('*/*/massDelete'),
             'confirm'  => Mage::helper('rule')->__('Are you sure?')
        ));
         return $this;
    }


then override Mage_Adminhtml_Promo_QuoteController class and add following code
public function massDeleteAction()
    { //exit;
        $rulesIds = $this->getRequest()->getParam('rule');
        if(!is_array($rulesIds)) {
             Mage::getSingleton('adminhtml/session')->addError(Mage::helper('adminhtml')->__('Please select rule(s).'));
        } else {
            try {
                $model = Mage::getModel('salesrule/rule');
                foreach ($rulesIds as $rulesId) {
                //echo $rulesId; exit;
                    $model->load($rulesId);
                    $model->delete();
                }
                Mage::getSingleton('adminhtml/session')->addSuccess(
                    Mage::helper('adminhtml')->__(
                        'Total of %d record(s) were deleted.', count($rulesIds)
                    )
                );
            } catch (Exception $e) {
                Mage::getSingleton('adminhtml/session')->addError($e->getMessage());
            }
        }

        $this->_redirect('*/*/index');
    }

Magento : Add massdelete action in magento admin grid

Consider module Bd_Demo and model Test

Add following lines in _prepareMassaction() method of admin grid file
protected function _prepareMassaction()
{
    $this->setMassactionIdField('id');
    $this->getMassactionBlock()->setFormFieldName('test');
    $this->getMassactionBlock()->addItem('delete', array(
         'label'    => Mage::helper('demo')->__('Delete'),
         'url'      => $this->getUrl('*/*/massDelete'),
         'confirm'  => Mage::helper('demo')->__('Are you sure?')
    ));
           
    return $this;
}

And following method in admin controller
public function massDeleteAction()
{
        $webIds = $this->getRequest()->getParam('test');
        if(!is_array($webIds)) {
               Mage::getSingleton('adminhtml/session')->addError(Mage::helper('adminhtml')->__('Please select item(s)'));
        } else {
            try {
                foreach ($webIds as $webId) {
                    $web = Mage::getModel('demo/test')->load($webId);
                    $web->delete();
                }
                Mage::getSingleton('adminhtml/session')->addSuccess(
                    Mage::helper('adminhtml')->__(
                        'Total of %d record(s) were successfully deleted', count($webIds)
                    )
                );
            } catch (Exception $e) {
                Mage::getSingleton('adminhtml/session')->addError($e->getMessage());
            }
        }
        $this->_redirect('*/*/index');
}

Magento : Add export CSV/XML functionality in magento admin grid

Consider module Bd_Demo and model Test, then
Add following lines in _prepareColumns() method of admin grid file
$this->addExportType('*/*/exportCsv', Mage::helper('demo')->__('CSV'));                              
$this->addExportType('*/*/exportXml', Mage::helper('demo')->__('XML'));

And add following methods in admin controller
public function exportCsvAction()
{
        $fileName   = 'test.csv';
        $content    = $this->getLayout()->createBlock('demo/adminhtml_test_grid')
            ->getCsv();

        $this->_sendUploadResponse($fileName, $content);
}

public function exportXmlAction()
{
        $fileName   = 'test.xml';
        $content    = $this->getLayout()->createBlock('demo/adminhtml_test_grid')
            ->getXml();

        $this->_sendUploadResponse($fileName, $content);
}

protected function _sendUploadResponse($fileName, $content, $contentType='application/octet-stream')
{
        $response = $this->getResponse();
        $response->setHeader('HTTP/1.1 200 OK','');
        $response->setHeader('Pragma', 'public', true);
        $response->setHeader('Cache-Control', 'must-revalidate, post-check=0, pre-check=0', true);
        $response->setHeader('Content-Disposition', 'attachment; filename='.$fileName);
        $response->setHeader('Last-Modified', date('r'));
        $response->setHeader('Accept-Ranges', 'bytes');
        $response->setHeader('Content-Length', strlen($content));
        $response->setHeader('Content-type', $contentType);
        $response->setBody($content);
        $response->sendResponse();
        die;
}

Magento : Add custome button and remove button in magento admin grid

Consider module 'Bd_Demo' and Model 'Test'
Edit Grid Container File Test.php
public function __construct()
{
        $this->_controller = 'adminhtml_test';
        $this->_blockGroup = 'test';
        $this->_headerText = Mage::helper('demo')->__('Test Manager');
        $this->_addButtonLabel = Mage::helper('demo')->__('Add Test');


        $this->_addButton('button1', array(
            'label'     => Mage::helper('demo')->__('Button Label1'),
        'onclick'   => "setLocation('".$this->getUrl('*/*/button1')."')",
           
        ));

    $this->_removeButton('add'); // remove Add test button

        parent::__construct();
}

Note : button1Action() method must be in admin controller

Magento : How to use ajax in admin grid

Searching/paging and other operations to all work in admin grid using ajax, is built in functionality, only follow following step
In constructor of Grid.php file, add following lines   
$this->setSaveParametersInSession(true);
$this->setUseAjax(true);

And in Grid.php add the function   
public function getGridUrl()
{
    return $this->getUrl('*/*/grid', array('_current'=>true));
}

And in your ControllerNameContrller.php add the action   
public function gridAction()
{
    $this->loadLayout();
    $this->getResponse()->setBody(
        $this->getLayout()->createBlock('modulename/adminhtml_modelname_grid')->toHtml()
    );
}