conditional tags چیست؟ کاربردهای تگ های شرطی در وردپرس

if ( is_user_logged_in() ):
    echo 'Welcome, registered user!';
else:
    echo 'Welcome, visitor!';
endif;

is_single( ’۱۷’ )
//is_single() can also check for certain posts by ID and other parameters. The above example proves true when Post 17 is being displayed as a single Post.

is_single( ‘Irish Stew’ )
//Parameters include Post titles, as well. In this case, it proves true when the Post with title “Irish Stew” is being displayed as a single Post.

is_single( ‘beef-stew’ )
//Proves true when the Post with Post Slug “beef-stew” is being displayed as a single Post.

is_single( array( 17, ‘beef-stew’, ‘Irish Stew’ ) )
//Returns true when the single post being displayed is either post ID 17, or the post_name is “beef-stew”, or the post_title is “Irish Stew”.

is_single( array( 17, 19, 1, 11 ) )
//Returns true when the single post being displayed is either post ID = 17, post ID = 19, post ID = 1 or post ID = 11.

is_single( array( ‘beef-stew’, ‘pea-soup’, ‘chilli’ ) )
//Returns true when the single post being displayed is either the post_name “beef-stew”, post_name “pea-soup” or post_name “chilli”.

is_single( array( ‘Beef Stew’, ‘Pea Soup’, ‘Chilli’ ) )
//Returns true when the single post being displayed is either the post_title is “Beef Stew”, post_title is “Pea Soup” or post_title is “Chilli”.

is_sticky( ’۱۷’ )
//Returns true when Post 17 is considered a sticky post.

if ( ‘book’ == get_post_type() ) …

is_post_type_hierarchical( ‘book’ )
//Returns true if the book post type was registered as having support for hierarchical.

is_page()
//When any Page is being displayed.

is_page( ’۴۲’ )
//When Page 42 (ID) is being displayed.

is_page( ‘About Me And Joe’ )
//When the Page with a post_title of “About Me And Joe” is being displayed.

is_page( ‘about-me’ )
//When the Page with a post_name (slug) of “about-me” is being displayed.

is_page( array( 42, ‘about-me’, ‘About Me And Joe’ ) )
//Returns true when the Pages displayed is either post ID = 42, or post_name is “about-me”, or post_title is “About Me And Joe”.

is_page( array( 42, 54, 6 ) )
//Returns true when the Pages displayed is either post ID = 42, or post ID = 54, or post ID = 6.

<?php
  $paged = $wp_query->get( 'page' );
  if ( ! $paged || $paged < 2 ) {
    // This is not a paginated page (or it's simply the first page of a paginated page/post)    } else {
    // This is a paginated page.
} ?>

<?php $paged = get_query_var( 'page' ) ? get_query_var( 'page' ) : false;
    if ( $paged == false )  {
    // This is not a paginated page (or it's simply the first page of a paginated page/post) }  else  {
    // This is a paginated page.
    }
?>

<?php  global $post; // if outside the loop
   if ( is_page() && $post->post_parent ) {
    // This is a subpage
          } else {
    // This is not a subpage
    }
?>

function is_subpage() {
    global $post;                              // load details about this page
 
    if ( is_page() && $post->post_parent ) {   // test to see if the page has a parent
        return $post->post_parent;             // return the ID of the parent post
 
    } else {                                   // there is no parent so ...
        return false;                          // ... the answer to the question is false
    }
}

  
<?php if ( is_page( 'about' ) || '2' == $post->post_parent ) {
    // the page is "About", or the parent of the page is "About"
    $bannerimg = 'about.jpg';
} elseif ( is_page( 'learning' ) || '56' == $post->post_parent ) {
    $bannerimg = 'teaching.jpg';
} elseif ( is_page( 'admissions' ) || '15' == $post->post_parent ) {
    $bannerimg = 'admissions.jpg';
} else {
    $bannerimg = 'home.jpg'; // just in case we are at an unclassified page, perhaps the home page
}
?>

function is_tree( $pid ) {      // $pid = The ID of the page we're looking for pages underneath
    global $post;               // load details about this page
 
    if ( is_page($pid) )
        return true;            // we're at the page or at a sub page
 
    $anc = get_post_ancestors( $post->ID );
    foreach ( $anc as $ancestor ) {
        if( is_page() && $ancestor == $pid ) {
            return true;
        }
    }
 
    return false;  // we aren't at the page, and the page is not an ancestor
}

is_page_template( ‘about.php’ )
//Is Page Template ‘about’ being used?

is_page_template( ‘page-templates/about.php’ )

is_category()
//When a Category archive page is being displayed.

is_category( ‘۹’ )
//When the archive page for Category 9 is being displayed.

is_category( ‘Stinky Cheeses’ )
//When the archive page for the Category with Name “Stinky Cheeses” is being displayed.

is_category( ‘blue-cheese’ )
//When the archive page for the Category with Category Slug “blue-cheese” is being displayed.

is_category( array( 9, ‘blue-cheese’, ‘Stinky Cheeses’ ) )
//Returns true when the category of posts being displayed is either term_ID 9, or slug “blue-cheese”, or name “Stinky Cheeses”.

in_category( ‘۵’ )
//Returns true if the current post is in the specified category id.

in_category( array( 1, 2, 3 ) )
//Returns true if the current post is in either category 1, 2, or 3.

! in_category( array( 4, 5, 6 ) )
//Returns true if the current post is NOT in either category 4, 5, or 6. Note the ! at the beginning.

is_tag()
//When any Tag archive page is being displayed.

is_tag( ‘mild’ )
//When the archive page for tag with the slug of ‘mild’ is being displayed.

is_tag( array( ‘sharp’, ‘mild’, ‘extreme’ ) )
//Returns true when the tag archive being displayed has a slug of either “sharp”, “mild”, or “extreme”.

has_tag()
//When the current post has a tag. Must be used inside The Loop.

has_tag( ‘mild’ )
//When the current post has the tag ‘mild’.

has_tag( array( ‘sharp’, ‘mild’, ‘extreme’ ) )
//When the current post has any of the tags in the array.

is_tax()
//When any Taxonomy archive page is being displayed.

is_tax( ‘flavor’ )
//When a Taxonomy archive page for the flavor taxonomy is being displayed.

is_tax( ‘flavor’, ‘mild’)
//When the archive page for the flavor taxonomy with the slug of ‘mild’ is being displayed.

is_tax( ‘flavor’, array( ‘sharp’, ‘mild’, ‘extreme’ ) )
//Returns true when the flavor taxonomy archive being displayed has a slug of either “sharp”, “mild”, or “extreme”.

has_term()
//Check if the current post has any of given terms. The first parameter should be an empty string. It expects a taxonomy slug/name as a second parameter.

has_term( ‘green’, ‘color’ )
//When the current post has the term ‘green’ from taxonomy ‘color’.

has_term( array( ‘green’, ‘orange’, ‘blue’ ), ‘color’ )
//When the current post has any of the terms in the array.

is_author( ‘۴’ )
//When the archive page for Author number (ID) 4 is being displayed.

is_author( ‘Vivian’ )
//When the archive page for the Author with Nickname “Vivian” is being displayed.

is_author( ‘john-jones’ )
//When the archive page for the Author with Nicename “john-jones” is being displayed.

is_author( array( 4, ‘john-jones’, ‘Vivian’ ) )
//When the archive page for the author is either user ID 4, or user_nicename “john-jones”, or nickname “Vivian”.

is_date()
//When any date-based archive page is being displayed (i.e. a monthly, yearly, daily or time-based archive).

is_year()
//When a yearly archive is being displayed.

is_month()
//When a monthly archive is being displayed.

is_day()
//When a daily archive is being displayed.

is_time()
//When an hourly, “minutely”, or “secondly” archive is being displayed.

is_new_day()
//If today is a new day according to post date. Should be used inside the loop.

<?php // Get $post if you're inside a function global $post;
   if ( empty( $post->post_excerpt ) ) {
    // This post has no excerpt
   } else {
    // This post has excerpt
  }
?>

<?php
  if ( ! has_excerpt() ) {
      echo '';
  } else {
      the_excerpt();
  }
?>

<?php if ( ! has_excerpt() ) {
    // you text or code
} ?>

//Any Archive Page
is_archive()
//When any type of Archive page is being displayed. Category, Tag, Author and Date based pages are all types of Archives.

//A Search Result Page
is_search()
//When a search result page archive is being displayed.

//A 404 Not Found Page
is_404()
//When a page displays after an “HTTP 404: Not Found” error occurs.

//An Attachment 
is_attachment()
//When an attachment document to a post or Page is being displayed. An attachment is an image or other file uploaded through the post editor’s upload utility. Attachments can be displayed on their own ‘page’ or template.

//A Single Page, Single Post or Attachment 
is_singular()
//When any of the following return true: is_single(), is_page() or is_attachment().

is_singular( ‘book’ )
//True when viewing a post of the Custom Post Types book.

is_singular( array( ‘newspaper’, ‘book’ ) )
//True when viewing a post of the Custom Post Types newspaper or book.

//A Syndication
is_feed()
//When the site requested is a Syndication. This tag is not typically used by users; it is used internally by WordPress and is available for Plugin Developers.

//A Trackback
is_trackback()
//When the site requested is WordPress’ hook into its Trackback engine. This tag is not typically used by users; it is used internally by WordPress and is available for Plugin Developers.

//A Preview 
is_preview()
//When a single post being displayed is viewed in Draft mode.

//Has A Nav Menu Assigned
has_nav_menu()
//Whether a registered nav menu location has a menu assigned
//Returns: assigned(true) or not(false)

//Inside The Loop 
in_the_loop()
//Check to see if you are “inside the loop”. Useful for plugin authors, this conditional returns as true when you are inside the loop.

//Is Sidebar Active 
is_active_sidebar()
//Check to see if a given sidebar is active (in use). Returns true if the sidebar (identified by name, id, or number) is in use, otherwise the function returns false.

//Part of a Network (Multisite)
is_multisite()
//Check to see whether the current site is in a WordPress MultiSite install.

//Main Site (Multisite)
is_main_site()
//Determines if a site is the main site in a network.

//Admin of a Network (Multisite)
is_super_admin()
//Determines if a user is a network (super) admin.

//An Active Plugin 
is_plugin_active()
//Checks if a plugin is activated.

//A Child Theme 
is_child_theme()
//Checks whether a child theme is in use.

//Theme supports a feature
current_theme_supports()
//Checks if various theme features exist.