What is PRADO?

PRADO is a component-based and event-driven programming framework for developing Web applications in PHP 5. PRADO stands for PHP Rapid Application Development Object-oriented.

A primary goal of PRADO is to enable maximum reusability in Web programming. By reusability, we mean not only reusing one's own code, but also reusing other people's code in an easy way. The latter is more important as it saves the effort of reinventing the wheels and may cut off development time dramatically. The introduction of the concept of component is for this purpose.

To achieve the above goal, PRADO stipulates a protocol of writing and using components to construct Web applications. A component is a software unit that is self-contained and can be reused with trivial customization. New components can be created by simple composition of existing components.

To facilitate interacting with components, PRADO implements an event-driven programming paradigm that allows delegation of extensible behavior to components. End-user activities, such as clicking on a submit button, are captured as server events. Methods or functions may be attached to these events so that when the events happen, they are invoked automatically to respond to the events. Compared with the traditional Web programming in which developers have to deal with the raw POST or GET variables, event-driven programming helps developers better focus on the necessary logic and reduces significantly the low-level repetitive coding.

In summary, developing a PRADO Web application mainly involves instantiating prebuilt component types, configuring them by setting their properties, responding to their events by writing handler functions, and composing them into pages for the application. It is very similar to RAD toolkits, such as Borland Delphi and Microsoft Visual Basic, that are used to develop desktop GUI applications.

Why PRADO?

PRADO is mostly quoted as a unique framework. In fact, it is so unique that it may turn your boring PHP programming into a fun task. The following list is a short summary of the main features of PRADO,

  • Reusability - Code following the PRADO component protocol are highly reusable. This benefits development teams in the long run as they can reuse their previous work and integrate other parties' work easily.
  • Event-driven programming - End-user activities, such as clicking on a submit button, are captured as server events so that developers have better focus on dealing with user interactions.
  • Team integration - Presentation and logic are separately stored. PRADO applications are themable.
  • Powerful Web controls - PRADO comes with a set of powerful components dealing with Web user interfaces. Highly interactive Web pages can be created with a few lines of code. For example, using the datagrid component, one can quickly create a page presenting a data table which allows paging, sorting, editing, and deleting rows of the data.
  • Strong database support - Since version 3.1, PRADO has been equipped with complete database support which is natively written and thus fits seemlessly with the rest part of the PRADO framework. According to the complexity of the business objects, one can choose to use the simple PDO-based data access, or the widely known active record, or the complete business object mapping scheme SqlMap.
  • Seamless AJAX support - Using AJAX in PRADO has never been easier with its innovative active controls introduced since version 3.1. You can easily write an AJAX-enabled application without writing a single line of javascript code. In fact, using active controls is not much different from using the regular non-AJAX enabled Web controls.
  • I18N and L10N support - PRADO includes complete support for building applications with multiple languages and locales.
  • XHTML compliance - Web pages generated by PRADO are XHTML-compliant.
  • Accommodation of existing work - PRADO is a generic framework with focus on the presentational layer. It does not exclude developers from using most existing class libraries or toolkits. For example, one can AdoDB or Creole to deal with DB in his PRADO application.
  • Other features - Powerful error/exception handling and message logging; generic caching and selective output caching; customizable and localizable error handling; extensible authentication and authorization; security measures such as cross-site script (XSS) prevention, cookie protection, etc.

What Is PRADO Best For?

PRADO is best suitable for creating Web applications that are highly user-interactive. It can be used to develop systems as simple as a blog system to those as complex as a content management system (CMS) or a complete e-commerce solution. Because PRADO promotes object-oriented programming through its component-based methodology, it fits extremely well for team work and enterprise development.

PRADO comes with a complete set of caching techniques which help accelerate PRADO Web applications to accommodate high traffic requirement. Its modular architecture allows developers to use or plug in different cache modules for different needs. The output caching enables one to selectively choose to cache part of a rendered Web page.

How Is PRADO Compared with Other Frameworks?

PRADO is often quoted as a unique framework. Its uniqueness mainly lies in the component-based and event-driven programming paradigm that it tries to promote. Although this programming paradigm is not new in desktop application programming and not new in a few Web programming languages, PRADO is perhaps the first PHP framework enabling it.

Most PHP frameworks mainly focuses on separating presentation and logic and promotes the MVC (model-view-controller) design pattern. PRADO achieves the same goal naturally by requiring logic be stored in classes and presentation in templates. PRADO does much more on aspects other than MVC. It fills lot of blank area in PHP Web programming with its component-based programming paradigm, its rich set of Web controls, its powerful database support, its flexible error handling and logging feature, and many others.

Is PRADO Stable Enough?

Yes. PRADO was initially released in August 2004. Many test suites have been written and conducted frequently to ensure its quality. It has been used by thousands of developers and many Web applications have been developed based on it. Bugs and feature requests are managed through TRAC system and we have a great user community and development team to ensure all questions are answered in a timely fashion.

History of PRADO

The very original inspiration of PRADO came from Apache Tapestry. During the design and implementation, I borrowed many ideas from Borland Delphi and Microsoft ASP.NET. The first version of PRADO came out in June 2004 and was written in PHP 4. Driven by the Zend PHP 5 coding contest, I rewrote PRADO in PHP 5, which proved to be a wise move, thanks to the new object model provided by PHP 5. PRADO won the grand prize in the Zend contest, earning the highest votes from both the public and the judges' panel.

In August 2004, PRADO started to be hosted on SourceForge as an open source project. Soon after, the project site xisc.com was announced to public. With the fantastic support of PRADO developer team and PRADO users, PRADO evolved to version 2.0 in mid 2005. In this version, Wei Zhuo contributed to PRADO with the excellent I18N and L10N support.

In May 2005, we decided to completely rewrite the PRADO framework to resolve a few fundamental issues found in version 2.0 and to catch up with some cool features available in Microsoft ASP.NET 2.0. After nearly a year's hard work with over 50,000 lines of new code, version 3.0 was finally made available in April 2006.

Starting from version 3.0, significant efforts are allocated to ensure the quality and stability of PRADO. If we say PRADO v2.x and v1.x are proof-of-concept work, we can say PRADO 3.x has grown up to a project that is suitable for serious business application development.