Deep analysis of the Get_template_part function _php technique of loading templates in WordPress

Recent research on the official theme Twenty eleven, there are some things online ready-made Chinese information is not easy to find, recorded in the blog, is to share, is also a memo, WordPress 3.0 After the beginning of the Get_template_part () this function, It should be a new feature that provides a more diverse selection of article presentation forms.

Examples of twenty eleven are as follows:

Twenty eleven index.php file
Line: 21

<?php if (have_posts ()):?>
 <?php twentyeleven_content_nav (' Nav-above ');?>
 <?php/* Start the loop is used in loops to invoke different types of articles/?>
 <?php while (Have_posts ()): The_post ();?> <?php Get_template_part
 (' C Ontent ', Get_post_format ());?>
 <?php endwhile; ...
......... .......
<?php endif;?>

Describe:
Load a set of templates into another template (different from containing header,sidebar,footer).
Makes it easy for a topic to use a child template to implement code snippet reuse

Used to include the specified template file in the template, you can include the file {slug}-{name}.php with the specified parameter slug and name, and the most important feature is that if the file does not contain a. php file without the {name}

How to use:

<?php Get_template_part ($slug, $name)?>

Parameters:

• $slug (must) generic template name
• $name (optional) the specified template name

Example:

Using loop.php in a child theme

Suppose the theme folder Wp-content/themes the parent theme is the Twentyten Twentytenchild, then the following code:

<?php get_template_part (' Loop ', ' Index ');?>

PHP's require () function will include files in the following priority

1. wp-content/themes/twentytenchild/loop-index.php
2. wp-content/themes/twentytenchild/loop.php
3. wp-content/themes/twentyten/loop-index.php
4. wp-content/themes/twentyten/loop.php

Navigation (this example sucks, but it's another way to use it)
To add a navigation bar to a theme using a common nav.php file:

<?php get_template_part (' nav ');      Navigation Bar (nav.php)?>
<?php get_template_part (' Nav ', ' 2 ');   Navigation bar #2 (nav-2.php)?>
<?php get_template_part (' Nav ', ' single ');//navigation bar to use in Sing Le pages (nav-single.php)?>

Get_template_part () The hook detailed
because the Get_template_part () function is heavily used in the official theme (twenty eleven), it should be considered a more popular function for the time being, and a previous article has written about the specific use of the function, Here is also inconvenient to repeat, this article mainly aimed at the function of the hook $tag value of the add_action, because, WP hook in a variety of functions in the $tag value is more puzzling.

The difference from a common hook
The ordinary Hook's $tag is a fixed value, and Get_template_part () is a variable value, well, let's not say, WP does this to us to achieve a simple function of how much trouble, but this setting does give a variety of theme implementation brings a lot of convenience.
To achieve this principle of the source code as follows, interception from the WordPress source program.

 function Get_template_part ($slug, $name = null) {
//$tag = "get_template_part_{$slug}" 
//That is, Get_template_ part_+ you set the $slug value
 do_action ("get_template_part_{$slug}", $slug, $name);
 $templates = Array ();
 if (Isset ($name))
  $templates [] = "{$slug}-{$name}.php";
  $templates [] = "{$slug}.php";
  Locate_template ($templates, True, false);

Instance
Like it said, maybe it's basically a little confused, okay? Give the point instance

Review the usage of Get_template_part ($slug, $name),
//If you get_template_part in the subject
(' Index ', ' photo ');
Then WP will go to the subject root directory index-photo.php file
 
//Then we want to hang a function like the following functions
addfunction ($slug, $name) {
echo $ slug;
}
Add_action ("Get_template_part_index", "AddFunction", 10,2);

Get_template_part () function Detailed memo