My Monkey Do

A Log of Coding Solutions

wordpress

WordPress 4.6 crashed my site

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Fatal error: Cannot redeclare the_post_thumbnail_caption() (previously declared in ….

This error occurs because the_post_thumbnail_caption is a new function in WordPress 4.6.  However, people have been using this function for over 5 years now.  How?  Stackoverflow and other WordPress forums are flooded with questions asking how they can print out the thumbnail caption.  Since this wasn’t a built-in function before, the answer was to make your own function which was appropriately named the_post_thumbnail_caption.

Many theme authors, myself included, are now guilty of simply copy-pasting this function without adding their own theme prefix.  To avoid errors like this, functions within a theme should be prefixed with something unique to the theme like “mymonkeytheme_the_post_thumbnail_caption”.

If you have this error, contact your theme author and ask them to fix the theme.

 

WordPress the_title filter changed in nav menus

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I haven’t had time to look into the exact reason or the exact version this changed, but as of at least WordPress version 4.5.2 the nav menu uses the_title multiple times for one item.

For example if your theme used something like this:


function menu_title_filter( $title ) {
return $title . ' | ';
}
add_filter( 'the_title', 'menu_title_filter' );

It would have one ” | ” after each menu title in previous versions, but in WordPress 4.5 ish it would show two ” | “.  Again, haven’t looked at the exact cause that changes this, but the solution is to check if the item you’re looking at is a nav_menu_item:

function menu_title_filter( $title, $id ) {
$item = get_post( $id );
if ( $item->post_type != 'nav_menu_item') return $title;
return $title . ' | ';
}
add_filter( 'the_title', 'menu_title_filter', 10, 2 );

Speed up WP_Query

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In WordPress, when a query does not need paging and you only want a limited amount of results, like the last 5 posts, set the ‘no_found_rows’ parameter to true.  This prevents WordPress from doing additional work in counting the total matched rows, thus speeding up your query.

This is already built into get_posts, but not WP_Query.

Example:

$last_5_query = WP_Query( array( ‘no_found_rows’=> true, ‘posts_per_page’=>5 ) );

Disable Responsive Images in WordPress

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In WordPress 4.4 images are displayed with the srcset attribute.  This attribute allows the browser to select alternative images for best viewing.  Sometimes though this may not be wanted as the image being displayed is the only image you want to show for all users.

To not have any srcset images, use the following:

add_filter( ‘wp_calculate_image_srcset_meta’, ‘__return_null’ );

For other filters new to WordPress 4.4, you can visit the blog post:

Responsive Images in WordPress 4.4

 

One user had a problem with the images in the srcset not having the https protocol and causing security warnings.  This stack overflow post resolves that:

http://wordpress.stackexchange.com/questions/211375/how-do-i-disable-responsive-images-in-wp-4-4

 

Run WP-Cron with no visitors

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Got a website with noone visits or simply a website that is private but still need WP-Cron to be run?  no problem, you have 2 easy options.

1) Setup a free account with set https://www.setcronjob.com ( i like them better because they enable email notifications on the free account).   Create a cron job to visit wp-cron.php on your domain.

2) set up a scheduled task or cron job on your computer.  Mac OS X and Windows PC.  Problem with this though is your computer needs to be on with internet access, and if you ever buy another computer (and don’t turn your current one on) this job will never run:

https://developer.wordpress.org/plugins/cron/hooking-into-the-system-task-scheduler/

Order Non-hierarchical Custom Post Types

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Non-hierarchical post types are like regular posts which normally do not have a menu_order attribute.  Hierarchical post type are like pages which allows a parent/child and is normally ordered by the menu_order attribute.  What if you have a custom post type that shouldn’t have a parent/child, but you still want to order it by something other than the post date?  This code does the trick on the admin side.

https://wordpress.org/support/topic/sorting-by-menu_order-in-admin-screen-on-non-hierarchical-custom-post-types