Detailed explanation of the usage of functions used to obtain categories and subpages in WordPress development, detailed explanation of wordpress_PHP tutorial

Detailed explanation of the usage of functions used to obtain categories and subpages in WordPress development, detailed explanation of wordpress

get_category
get_category Maybe we don’t have much contact with it, but it is very useful. It seems that there are not many introductions to this function on the Internet, so today I will only translate it for the official WordPress English document.

Function description
Get the specified category, returned in the form of an array or object.

Function usage

 get_category( $cat, $out, $filter )

Parameter description
$cat: category ID, or
$out return value type [OBJECT, ARRAY_A, or ARRAY_N]
$filter
Function return value
Here we mainly talk about the return value of the object type,
There are comments, please refer to them yourself.

stdClass Object
(
  //ID 分类和标签混编
  [term_id] => 5
  //分类名
  [name] => Cat Name
  //分类别名
  [slug] => cat
  //N/A
  [term_group] => 0
  //同 term_id
  [term_taxonomy_id] => 5
  //分类法，也就是分类还是标签
  [taxonomy] => category
  //分类描述
  [description] => 
  //父级ID
  [parent] => 70
  //N/A
  [count] => 0
  //分类ID
  [cat_ID] => 5
  //N/A
  [category_count] => 0
  //同 description
  [category_description] => 
  //同 name
  [cat_name] => Category Name
  //同 slug
  [category_nicename] => category-name
  //同 parent
  [category_parent] => 70
 
)

get_children()
Let’s take a look at the use of this function. get_children is somewhat similar to the get_posts function, but different. This function is mainly used to retrieve or return parent articles, child articles under the page, and attachments (important).

I hope some of the explanations in this article are helpful to you.

Meaning of get_children function
get_children() This function has been available since WordPress 2.0.0. It is mainly used to retrieve attachments, versions, subpages and other information. The usage of get_children() and get_posts() are basically the same.

Function usage

$args = array(
 'post_parent' => $postid,
 'post_type' => 'attachment',
 'numberposts' => 1,
 'post_mime_type' => 'image', );
if ($images = get_children($args))

Parameter explanation
$args['numberposts']
(integer) The number of sub-articles to be retrieved. Optional; default: -1 (unlimited)

$args[‘post_parent’]
(Integer) Pass the number of the post or page to get its child articles. Pass a null value to get the child articles of any article. Optional; default: 0 (any parent post?)

$args[‘post_type’]
(Character) The value in the post_type column in the article list, such as attachment, page or modification status; or the keyword any. Default value: any

$args[‘post_status’]
(char) The value in the post_status column in the post list, such as published, draft, or hereditary; or the keyword any. Default value: any

$args[‘post_mime_type’]
(Characters) The complete or incomplete mime type, such as image, video, video/mp4, that matches the post_mime_type field.

$output
(Constant) The variable type of the array item returned by any of the OBJECT, ARRAY_A, and ARRAY_N functions. Optional; default: OBJECT
Summary
get_children(), usually in the theme, is used to call out the image attachments in the article. That is to say, as long as you upload the image, even if your theme does not support featured images or you have not set up featured images, we can use this The function takes out the image you uploaded in the article. Although this has certain limitations, it is enough as a supplement to the featured image. As for fetching other sub-item content, I personally feel that it is not very useful. Moreover, because article pagination is generally not needed, I did not do a demo to test pagination. If you are studying the get_children() function, I hope this article can bring you good luck.

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