Analysis of PHP functions related to custom headers in WordPress topic creation

This article describes how to parse PHP functions related to custom headers in WordPress theme production, including header_image () and get_custom_header () functions. For more information, see Header_image ()
The header_image () function is a standard interface function used by WordPress to customize the top image. This function can automatically determine the background settings and return the user-defined top image address in string format. This document describes and uses this function.

[Display header image path.]: displays the top image address.
Use

The code is as follows:

"Width =" <? Php echo $ header_image_width;?> "Height =" <? Php echo $ header_image_height;?> "Alt =" "/>

Function declaration source code

function header_textcolor() { echo get_header_textcolor();}function get_header_image() { $url = get_theme_mod( 'header_image', get_theme_support( 'custom-header', 'default-image' ) );  if ( 'remove-header' == $url ) return false;  if ( is_random_header_image() ) $url = get_random_header_image();  if ( is_ssl() ) $url = str_replace( 'http://', 'https://', $url ); else $url = str_replace( 'https://', 'http://', $url );  return esc_url_raw( $url );}

Get_custom_header custom top
The get_custom_header function is a new gift from WordPress 3.4. This function is used to better integrate and encapsulate the use of the top layer, this article describes the get_custom_header function and how to integrate the top function in the topic of WordPress 3.4.

Make sure that your WordPress has been upgraded to version 3.4.

Get_custom_header
Currently, most themes on the custom top only use two functions. 1. Custom top image 2. Custom top style
For more information, see the default theme twenty eleven.
This function is a built-in function that appears only after WP 3.4. it is mainly used to return parameters at the top of the user's settings as objects.
You may not understand this. if you want to understand it, please read it down.
Note that this function is essentially different from get_header.

Function instance
The following example is from the header. php file in the default theme twenty eleven.
PHP code:

// Determine whether the function exists to be compatible with the old version if (function_exists ('Get _ custom_header ') {// get_custom_header () -> width call the directed width attribute $ header_image_width = get_custom_header ()-> width; // get_custom_header ()-> height call the directed height attribute $ header_image_height = get_custom_header ()-> height ;} else {// code compatible with earlier versions $ header_image_width = HEADER_IMAGE_WIDTH; $ header_image_height = HEADER_IMAGE_HEIGHT ;}

Comprehensive usage
Refer to the official document below to explain the custom top

// Enable the add_theme_support ('m M-head'); $ headarg = array (// package the settings into an array 'default-image' => '', 'random-default' => false, 'width' => 0, 'height' => 0, 'Flex-height' => false, 'flex-width' => false, 'default-text-color' => '', 'header-text' => true, 'uploads' => true, 'WP-head-callback' => '', 'admin-head-callback' =>'', 'admin-preview-callback' => '',); // add the settings in the array to the custom top add_theme_support ('custom-head', $ headarg );

Custom top image

// Enable the add_theme_support ('m M-head'); $ headarg = array (// package the settings into an array 'default-image' => '', 'random-default' => false, 'width' => 0, 'height' => 0, 'Flex-height' => false, 'flex-width' => false, 'default-text-color' => '', 'header-text' => true, 'uploads' => true, 'WP-head-callback' => '', 'admin-head-callback' =>'', 'admin-preview-callback' => '',); // add the settings in the array to the custom top add_theme_support ('custom-head', $ headarg );

Adaptive top image settings

$ Args = array ('flex-width' => true, // adaptive height 'width' => 980, 'Flex-width' => true, // adaptive width 'height' => 200, 'default-image' => get_template_directory_uri (). '/images/header.jpg',); add_theme_support ('m M-head', $ args );

Call custom top image

"   height="<?php echo get_custom_header()->height; ?>"   width="<?php echo get_custom_header()->width; ?>"   alt="" />