Almost every application uses a database connection and acl module. Why doing this in the bootstrap and to mantain many lines of code there, instead of making it clear and mantainable. Of course you can have all these lines of code in your bootstrap, but you know for serious applications that recently will become an obstacle. That’s why Zend Framework allows you to use Front_Controller plugin.

First in you bootstrap add those lines of code

/*
 * add a simple plugin to the controller
 */

$front->registerPlugin(new Zend_Controller_Plugin_Init())
      ->registerPlugin(new Zend_Controller_Plugin_Acl());

These two classes (Zend_Controller_Plugin_Init and Zend_Controller_Plugin_Acl) should be placed in two different files with the same names in Controller/Plugins directory under Zend folder, and garantee you that both classes will be instanciated before starting the front controller.

There is the example of Zend_Controller_Plugin_Init:

<?php

/** Zend_Acl */
require_once 'Zend/Acl.php';

/** Zend_Controller_Plugin_Abstract */
require_once 'Zend/Controller/Plugin/Abstract.php';

/**
 * Front Controller Plugin
 */
final class Zend_Controller_Plugin_Acl extends Zend_Controller_Plugin_Abstract
{

/**
 * @var Zend_Acl
 **/
protected $_acl;

/**
 * @var string
 **/
protected $_roleName;

/**
 * @var array
 **/
protected $_errorPage;

/**
 * Constructor
 *
 * @param mixed $aclData
 * @param $roleName
 * @return void
 **/
public function __construct()
{

// define the error controller
$this->_errorPage = array('module' => 'default', 'controller' => 'error',
    'action' => 'denied');

$this->_roleName = 'defaultRole';
// if (null !== $this->_acl) {
$this->_initAcl();
// }

}

/**
 * Returns the ACL object
 *
 * @return Zend_Acl
 **/
public function getAcl()
{
    return $this->_acl;
}

/**
 * Sets the ACL role to use
 *
 * @param string $roleName
 * @return void
 **/
public function setRoleName($roleName)
{
    $this->_roleName = $roleName;
}

/**
 * Returns the ACL role used
 *
 * @return string
 * @author
 **/
public function getRoleName()
{
    return $this->_roleName;
}

/**
 * Sets the error page
 *
 * @param string $action
 * @param string $controller
 * @param string $module
 * @return void
 **/
public function setErrorPage($action, $controller = 'error', $module = null)
{
$this->_errorPage = array('module' => $module,
    'controller' => $controller,
    'action' => $action);
}

/**
 * Returns the error page
 *
 * @return array
 **/
public function getErrorPage()
{
    return $this->_errorPage;
}

/**
 * Predispatch
 * Checks if the current user identified by roleName has rights to the requested url (module/controller/action)
 * If not, it will call denyAccess to be redirected to errorPage
 *
 * @return void
 **/

public function preDispatch(Zend_Controller_Request_Abstract $request)
{
    $resourceName = '';
    if ($request->getModuleName() != 'default') {
    $resourceName .= $request->getModuleName() . ':';
}

$resourceName .= $request->getControllerName();

/** Check if the controller/action can be accessed by the current user */
if (!$this->getAcl()->isAllowed($this->_roleName, $resourceName, $request->getActionName())) {

/** Redirect to access denied page */
$this->denyAccess();

}

}

/**
 * Deny Access Function
 * Redirects to errorPage, this can be called from an action using the action helper
 *
 * @return void
 **/
public function denyAccess()
{
   $this->_request->setModuleName($this->_errorPage['module']);
   $this->_request->setControllerName($this->_errorPage['controller']);
   $this->_request->setActionName($this->_errorPage['action']);
}

/**
 * initialize the acl object and resources
 * for the roles used in the application
 *
 */
private function _initAcl()
{
   /*
    * define access control list
    */
   $this->_acl = new Zend_Acl();

   /**
    * define acl for default role
    */
   $this->_acl->addRole(new Zend_Acl_Role('defaultRole'))
        ->add(new Zend_Acl_Resource('index'))
        ->add(new Zend_Acl_Resource('portfolio'))
        ->add(new Zend_Acl_Resource('user'))
        ->allow('defaultRole');

   /**
    * define acl for administrator
    */
   $this->_acl->addRole(new Zend_Acl_Role('admin'))
        ->add(new Zend_Acl_Resource('admin:index'))
        ->add(new Zend_Acl_Resource('admin:cpanel'))
        ->add(new Zend_Acl_Resource('admin:user'))
        ->add(new Zend_Acl_Resource('admin:page'))
        ->addRole(new Zend_Acl_Role('default'))
        ->allow('admin');

   }

}

Init.php
<?php

require_once 'Zend/Controller/Plugin/Abstract.php';
class Zend_Controller_Plugin_Init extends Zend_Controller_Plugin_Abstract
{
    public function __construct()
    {
        // require configuration
        require_once 'Zend/Config.php';

        // get configuration from ini file
        $config = new Zend_Config_Ini('../application/config.ini', 'dev');

        // connect to the database
        $db = new Zend_Db_Adapter_Pdo_Mysql($config->database->params);

        // assign the db adapter to be default for our models
        Zend_Db_Table::setDefaultAdapter($db);

        // register configuration at the registry
        Zend_Registry::set('config', $config);

        Zend_Registry::set('db', $db);

        // start layout mvc
        Zend_Layout::startMvc(array(
            'layoutPath' => '../application/layouts',
            'layout' => 'main'
        ));
    }

}

Although the SWFObject method – createSWF is working fine under IE sets the wmode not to be transparent but with the strange value of window, i.e. <PARAM name=”WMode” value=”Window” />

The Solution is …

to replace the createSWF method calls with other SWFObject method – embedSWF. There you can simply describe the desired wmode for the flash.

Zend_Date is the Zend Framework module for manipulation of dates. It gives several advantages. Everybody how has dealed with dates knows that built in PHP date function cannot manage dates before 1901. With that kind of problems Zend_Date is pretty fine.

How to do that

If you have only

Zend_Date::set($timestamp);

is not enough. The timestamp is an int representation and the framework cannot get the timezone from that and trows an error.

The simple way to solve the problem

Replace the line above with these:

$date = new Zend_Date($timestamp);

$date->setTimezone(‘Europe/Paris’);

print $date->toString(‘d M y’);

Now everything should be in place.

You’re using Flex 3 and want to compare two dates. The format of the dates is string something like “2009 May 05”. The question is …

What’s the best way to compare them

Well if you’ve the dates as strings and you can easily conver them to something like unix timestamps. If they are a Date object you can try lik so:

date1 = new Date(‘2009’);

date2 = new Date(‘1990’);

if (date1.setTime() < date2.setTime())

Zend_Loader was the usual kind of autoloading in Zend Framework before version 1.8. Than simply you say:

require_once “Zend/Loader.php”;
Zend_Loader::registerAutoload();

That made all your application to autoload files from the library folder where usualy the Zend Framework stays. That has several things to be changed.

The namespaces

There where not really namespaces for autoloading. Everything was searched to be loaded in one single namespace. And thus there where not the functionality to remove a namespace from the game. You have everything all the time.

Zend_Loader_Autoloader

This is new from version 1.8 in Zend Framework. Now you should use this class to autoload your classes. There’s really namespaces and for more info and detailed information you should search the documentation of the ZF.

The most simple way to switch from Zend_Loader to Zend_Loader_Autoloader

That’s really simple, and I don’t understand why there’s not proper explanation how to do that in the ZF docs. You need to replaces this lines of code:

require_once “Zend/Loader.php”;
Zend_Loader::registerAutoload();

with these:

require_once ‘Zend/Loader/Autoloader.php’;
$autoloader = Zend_Loader_Autoloader::getInstance();
$autoloader->setFallbackAutoloader(true);

Yes in our case this was the fact. There were two web servers, Apache 2 in our case, and one PHP. The php.ini file was in /etc/ as usual. Everything seemed to be perfect. But however some directives in php.ini does not worked for one of the server.

Why the second server does not read php.ini?

Well actually when you load the php.ini for the first server it loads correctly with everthing declared in it. However when you start the second server, of course on a different port than the first one, you get all the php.ini values as if they are default.

Why?

That’s some feature of PHP we didn’t know. I still don’t have an explanation about it. But of cource there’s a …

Workaround

You can put everything for the second server in the .htaccess file, so this will act as second php.ini for the second web server

When the HSlider is set up with two or more thumbs there’s a gap between them always. The problem is that you may want to put them on one single value of the slider, but it’s not possible.

First: hide your thumbs

The quick solution is to make custom skin for the thumbs, setup the height and width of the thumb to be 1px and make a transparent background image for skinning them. That of course does not solve the problem. There’s still gap of 1 value between the thumbs, and still you cannot select one single value with both of them.

Make your own thumbs

It’s difficult to make the calculation and positioning of course. With that approach you’ve to be careful with the math to adjust properly the new thumbs. They can be some kind of Flex built in component. As the button control is or whatever.

Hope for workaround

As it appears there’s a reported bug for this issue. And I hope soon there will be a workaround or even better there’s going to be new version. Something I don’t like in commercial software.

That can be done with window.scrollBy(x, y). Where if you’d like to scroll vertically you’ve to change the y value.

For those who don’t know base64 it’s an encoding format for any data. In that case with the images we can simply say, that base64 equals to text (string) representation of the image itself. In most cases you’ve image tags with src attribute pointing to the http source of the image.

Overview of the problem

Let’s say we’ve a HTML document with 100 images into. That’s a rare case I agree, but sometimes it happens. You’ve to preload the thumbnails of an image gallery where only one image is displayed in a bigger size. As I mentioned before the progressive JPEG suits better for a large image but for the thumbnails you’ve to use baseline JPEGs.

Note: In fact the technique with base64 representation of the images is not well known. I think that’s because there are not so much examples with pages with more than 100 images.

But anyway. We’ve the HTML document with 100 images (100 <img> tags). That means directly 101 requests/responses from the server. In my tests on my localhost, which is supposed to be fast enough, that case loaded 2 MB with a simple small JPEG for the image, loaded 100 times, and approximately 3 seconds. Which yet again on the localhost is extreamly slow. The image is on my machine, the server is here… what else?

How to put the images inline?

The other way to do that is to put all you images in you HTML document. Than the first and more important rule for optimization (see more here), to make fewer requests is done. You now have only one request. And with the response you’ve all 100 images. That’s good when you’ve different images, cause every repeatable element in your CSS should be made with HTTP request once and than repeated with the CSS. In other way you risk the size of the document transfered in the web.

The results

The second case with the inline images and the only one request is giving me an average response time of 900ms. The size of the document is bigger, yes. I had 5KB for the HTML with no base64 images, and then the size increased to 45KB. That’s 9 times more. But however 45KB is nothing for the web, instead of all those 2 MB in the previous test.

How to make your images to strings?

Speaking in PHP terminology there is a function called base64_encode, which with a combination of file_get_contents(imagefile), make the files a base64 string.

Is there any issue?

Yes there is. First you cannot have your image files in a remote server, cause file_get_contents must read only from the local filesystem. Than if you process all those files before returning them to the client, where’s the point? You lose all that time you’ve spent with the technique.

The reasonable solution

I think this technique is good for cases like the one described at the beggining. You’ve a page with more than 100 images. Then you’ve the base64 representation already. Let say you have it in your database as string and don’t need to convert it everytime you return the image. That may happen on upload of the image and the image enters the database with its base64 representation, and it’s done.

Everybody knows that sometimes you need header and footer for almost every page. In Zend Framework you don’t need to include them in every template page, as it will be if you were using Smarty for instance. You just need to use Zend_Layout. It’s easy and it’s helpful.

What if you don’t need layout for a controller action?

Well if you have to have a given controller action with no use of Zend_Layout, you just need to disable it.

How …

… simply by placing this line in you controller action:

$this->_helper->layout->disableLayout();