Tag Archives: PHP programming language

Cool tutorial about Zend_Paginator

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Every part of Zend Framework is indeed very profesional and useful. But as it happens often some modules are less used than others. Don’t know why but my feeling is that Zend_Paginator, a wonderful tool for pagination is really misunderstood. And in fact it does one of the most common web development tasks. It builds the abstraction for a component that everybody uses in a web project – pagination.

It make sense if there where more tutorials like the following one describing its usage! Many thanks to Joey Rivera for a great tutorial about Zend_Paginator.

Even more this tutorials goes behind the pure usage of the paginator but it helps you understand the integration with one of the most used web apps today – Twitter and another Zend Framework component – Zend_Cache.

joey rivera blog

Theory of caching. Zend_Cache & Zend Optimizer.

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Although it may sound strange I’ll say why I’m using caching. Because it speeds up the site! Yeah there’s no other reason that may be so important as this is.

The caching is not a process invented in the last year, it’s useless to describe why do you need it, but however my intention is to describe how to make it work with Zend Framework.

The docs page of Zend_Cache is pretty clear about everything and I’ll describe the most important part of the cache setup.

First setup the cache back and frontend options. You need to decide where to save the cache files, how to cache them, and what lifetime do they need.

The most used cache configuration is, as you may guess, this one described into the doc page. Setup the front and backend options is just as simple as:

$frontendOptions = array(
     'lifetime' => 7200, // cache lifetime of 2 hours
     'automatic_serialization' => true
);

$backendOptions = array(
   'cache_dir' => './tmp/'
   // Directory where to put the cache files
);

// getting a Zend_Cache_Core object
$cache = Zend_Cache::factory('Core',
                             'File',
                              $frontendOptions,
                              $backendOptions);

Because all this is well described into the doc page, which you can found here I won’t talk about it. But I’ll talk only about one sole thing. How much the cache must live? What should be its lifetime.

The answer is simple. If you have some basic statistic of your site traffic and you don’t change much the data you can prefer longer cache period. But imagine the site’s making 1000 visits per minute! Than even if you cache every minute and the cache expires every minute will be a success and the user perception will be really great. From those 1000 visitors only few will wait until the cache’s built and the other hundreds will receive really fast response!

Be careful when you cache only because you can overflow the directory where you cache, which will be difficult though.

In other way many people are thinking about Zend Optimizer and its work with Zend_Cache. These are really different things. Zend Optimizer has nothing to do with your code it is a PHP caching tool. As you may know PHP interpreter mingles the code into “machine like” code, which in turn can be cached into the RAM with the help of Zend Optimizer. Checkout more here.

Using Zend Framework validators – Zend_Validate_Db_RecordExists

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What are validators?

In very very breve these are methods which can validate some data, usually user input, against some specific rules. Imagine there’s a web form that is always checked for empty fields or some fields that may contain valid e-mail addresses. This is so common that became everyday routine to almost all of us. However smart developers make abstractions that help them reuse all this functionality. Even smarter developers make use of frameworks. And for those of you, using Zend Framework, there’s no need to write most of the common used validators, simply because they come with the framework itself.

Technically you’ve various validators in zend, such as Zend_Validate_Alnum, Zend_Validate_Email or Zend_Validate_Regex. All these are extremely useful when it comes to automatic, bullet proof validation, but I’m going to talk more about one specific validator.

Zend_Validate_Db_RecordExists

Although the implementation is nothing more than just a chunk of code and doesn’t pretend to be difficult, the idea of such validator is genius indeed. It really helps you do some amazing job.

Image you have to check some database record existence. Then comes in help this validator. In fact I’m pretty sure almost everyone has experience with such kind of task. Simply because the registration process almost always requires it. When you try to register new user you more often check for the username existence. Although you may solve the problem with other technique by catching the exception the database is throwing for duplicate entries, this should be assumed just as an example.

I’m pretty sure this validator can be really useful in many occasions!

Zend_Date – make it work and benefit with locales

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Although the documentation of Zend Framework is one of the most well structured documentation I’ve ever read it happened to me to stuck into it. And that happened exactly when I tried to use the date component of ZF – Zend_Date.

Why I’d prefer Zend_Date?

We all know what the date function of PHP is, and what it does. It has reach set of formating string that help you do the job but as I’m working mostly on multilingual projects almost every project needs multilingual dates, and more or less nobody wants only numbers into the dates. And all this is pretty natural, instead of using the simple

01.01.2010

format, which beside it’s natural ugliness is not clear. Because as you may know in the US this can be understood as month.date.year, while in Europe this is date.month.year. And when it comes to dates like 02.01.2010 this can be really frustrating.

Beside this ugly format, you can choose to format your dates either with:

1 January 2010 or 1 Jan 2010

which is clear enough, but it’s only for english speakers. You know that in a spanish speaking country you should format the same date as:

1 Ene 2010

where “ene” means enero – january in spanish. How should you overcome this natural PHP problem?

Well the answer is by using Zend_Date

The problem I found in Zend_Date usage is that the native copy/paste technique from the doc page doesn’t seem to work. What the doc page says you is:

// setup the default timezone
date_default_timezone_set('Europe/London');

and than you can simply request a date with:

$date = new Zend_Date(‘2010-01-02’);
echo $date->get('d MMM yyyy');

where this should print 1 Jan 2010.

It’s a shame that this doesn’t work. The good part is that this problem can be overcome very simply. You just need to setup some more things just before calling the get method.

First setup a cache mechanism where you can cache the date locales. This is really good practice because it speeds up the framework when dealing with dates. Just add those lines after the default timezone is set:

// setup the default timezone
date_default_timezone_set('Europe/London');

$locale = new Zend_Locale(‘es_ES’);
Zend_Registry::set('Zend_Locale', $locale);

$frontendOptions = array(
		'lifetime' => 600, // 10 minutes
		'automatic_serialization' => true
);

$backendOptions = array(
                'cache_dir' => '../cache/'
		);

// getting a Zend_Cache_Core object
$cache = Zend_Cache::factory('Core',
		             'File',
		              $frontendOptions,
		              $backendOptions);

First you setup the Zend_Locale – a locale for the entire application and set it up in this example for spanish, than setup the cache mechanism.

This is a typical cache setup for Zend Framework. If you’d like to dive more into cacheing you can checkout the doc pages for Zend_Cache.

After these lines just setup Zend_Date options with:

Zend_Date::setOptions(array('format_type' => 'php',
                   'cache' => $cache));

This is really what you need to do to start. All these lines of code you may place into the bootstrap.php or into some front controller plugin.

Then you can call Zend_Date’s get method wherever you’d like in every controller you need it!

Redirecting with Zend Framework – part 2

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Recently I posted about the redirecting mechanism of Zend Framework. It’s a working chunk of code but the problem is that it seems quite difficult in according with other ZF sample codes.

Yes the same goal can be achieved with less effort. Like the _forward function which just executes other action/controller, you can call the _redirect method to rewrite the URI.

Just use that in any action of any controller:

$this->_redirect('http://www.example.com');

That executes exactly the same as calling the header PHP method or echoing the <meta> refresher!