what is php template engine

PHP is an HTML-embedded scripting language executed on the server side, so the initial development template for most web applications developed in PHP is mixed-layer data programming.

Although the MVC design pattern can forcefully separate the program application logic and the web page rendering logic, it only separates the input, processing and output of the application program, and the web page rendering logic (View) There will also be HTML code and PHP programs that are strongly coupled together. (Recommended learning:PHP programming from entry to proficiency)

The writer of PHP scripts must be both a web designer and a PHP developer. But the reality is that most web developers are either proficient in web design and can design beautiful web page appearances, but write poor PHP code; or they are only familiar with PHP programming and can write robust PHP code, but design web page appearance. very ugly. Developers with both talents are rare.

There are many solutions that can almost completely separate the page design of the website and the PHP application. These solutions are called "template engines" and they are gradually eliminating the difficulties caused by the lack of hierarchical separation.

The purpose of the template engine is to achieve the function of logical separation mentioned above. It allows program developers to focus on data control or function implementation; while web designers can focus on web page layout to make web pages look more professional. Therefore, the modeling engine is ideal for use by a company's web development team, allowing everyone to contribute to their expertise.

The core of template engine technology is relatively simple. Just specify the art page (which does not contain any PHP code) as a template file, and define active content in this template file, such as database output, user interaction, etc., as "variables" contained using special "delimiters" " and then place it in the corresponding location in the template file.

When the user browses, the template file is opened by the PHP script program and the variables defined in the template file are replaced. In this way, when special variables in the template are replaced with different dynamic content, the required page will be output.

Art designers can work independently from application developers because the application's presentation and logic are not inextricably intertwined. Additionally, because the presentation logic used by most template engines is generally simpler than the syntax of the programming language used by the application, artists do not need to expend as much effort in the programming language to complete their work.

You can use the same code to generate data based on different goals, such as generating printed data, generating Web pages, or generating spreadsheets. If you do not use a template engine, you need to copy and modify the code for each output target, which will bring very serious code redundancy and greatly reduce manageability.

Currently, there are many relatively mature templates that can be applied in PHP, such as Smarty, PHPLIB, IPB, xingTemplate and dozens more. Using these template engines written in PHP can make your code context clearer and the structure more rational.

It can also make website maintenance and updates easier, create a better development environment, and make it easier to combine development and design work.

However, for a PHP programmer, no PHP template is the most suitable and perfect for him. Because PHP templates are popular things and are not developed for a certain person.

If you can fully understand the advantages and disadvantages of templates based on a clear understanding of their characteristics and applications, you can know whether to choose to use a template or which template to use.

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