wordpress template in-depth analysis of php template technology principles

1. The origin of templates Before there was template technology, when PHP was used to develop programs, PHP code and HTML were usually mixed together. For example, the news list is probably a newslist.php page with the following structure: //Read the news records to be displayed from the database ?> … ….. While ($news = mysql_fetch_array($result)) { ?> &lt ;? } ?> So what’s the problem with this? First, it is not conducive to division of labor and cooperation. Generally speaking, programmers write the code and artists design the pages. In this approach, the programmer must wait for the artist to design the interface before starting work. In other words, the work of programmers and artists cannot be synchronized. Secondly, it is not conducive to maintenance and has poor maintainability. For example, if you want to modify the interface after the program is fixed, the artist must modify it and then the programmer can add it again. Finally, the program structure is confusing and readable. HTML and PHP are mixed together, and once there are too many programs, it will become very messy. Understand the principles of templates - template technology using PHP tags Template technology emerged precisely to solve these problems. In order to solve these problems, the earliest template technology that appeared was the template technology using PHP tags. First, we need to understand what the purpose of the template is. How many tasks does the template mainly need to achieve? First, the separation of art and programming. More precisely, it is the separation of obtaining data and displaying data. Second, division of labor. Good division of labor and cooperation. For example, for the news list, if we use templates, we can divide the operation of the news list into two parts: 1. getnews.php is responsible for reading data from the database into the array $news, and does not care how $news is displayed. 2. Shownews.php is responsible for outputting the $news array into an HTML page. And it doesn't need to care where $news comes from. Okay, in this way, we have achieved the separation of art and programming and achieved our initial goal. But how to combine these two pages and realize the functions of listnews.php? This requires another page, listnews.php, to connect "artist (display data)" and "programmer (get data)". It should be said that this page is very simple. Assume that the code of getnews.php is as follows: $news = "News List"; //In fact, it should be read from the database. ?> $news?> Include('shownesw.php');//Display data ?> Summary Using the template system of PHP tags can achieve a good separation of artists and programs, and at the same time facilitate the division of labor and cooperation between programmers and artists. For example, in the above example, shownews.php is maintained by artists, and getnews.php is maintained by programmers. And listnews.php can be maintained by system designers. Of course, some agreed documents need to be added. In fact, this simple example also illustrates the most basic MVC model. Among them, M, model, is responsible for reading data, which is equivalent to our getnews.php. V is the view, used to display data, which corresponds to shownews.php. Finally, there is controller C, which corresponds to our listnews.php Learn interpretive template technology - PHPLIB Phplib's template system has won the favor of many phpers for its small, flexible, convenient and simple features, and occupies a certain position in template technology. It and template engines such as fasttemplate are interpretive template technologies. Before explaining the use of phplib in detail, let me first explain why the template system using php tags needs to continue to be improved. In fact, this is mainly because PHP tags are inconvenient for artists. They prefer to use this visual tag directly, such as {title}. First of all, we modified our previous example to use visual tags.The first step is to change shownews.php to shownews.tpl, and replace the php tags inside with visual tags. The code of shownews.tpl is as follows: Show News {title} Second step, how to achieve the effect of listnews.php? It's actually very simple. I just need to replace {title} directly, right? Therefore, the modified listnews.php code is as follows: Include('getnews.php');//Get data echo str_replace('{title}',$news,file_get_contents('shownews.tpl' )) ?> In fact, the principle of phplib is exactly like this! For example, if we want to use phplib to implement the above function, we only need to modify listnews.php. The modified code is as follows: Include('getnews.php');//Get data include('template.class. php'); $t=new Template(); $t->set_file('shownesw,'shownews.tpl'); $t->set_var('news',$news); $t ->parse('out', 'shownesw'); $t->p('out'); ?> In addition, regarding the phplib area, you can check the corresponding manual. Compiled samrty, let’s continue talking about it next time

The above introduces the WordPress template and in-depth analysis of the technical principles of PHP templates, including the content of WordPress templates. I hope it will be helpful to friends who are interested in PHP tutorials.