Add Metaboxes and display them
<?php
// Do NOT include the opening php tag
// Adds a box to the main column on the Post and Page edit screens. Goes to Dynamik Custom - Functions.
// From: https://codex.wordpress.org/Function_Reference/add_meta_box
function myplugin_add_meta_box() {
$screens = array( 'post', 'page' );
foreach ( $screens as $screen ) {
add_meta_box(
'mymetabox',
__( 'This is my Custom Meta box', 'myplugin_textdomain' ),
'myplugin_meta_box_callback',
$screen
);
}
}
add_action( 'add_meta_boxes', 'myplugin_add_meta_box' );
/**
* Prints the box content.
*
* @param WP_Post $post The object for the current post/page.
*/
function myplugin_meta_box_callback( $post ) {
// Add a nonce field so we can check for it later.
wp_nonce_field( 'myplugin_save_meta_box_data', 'myplugin_meta_box_nonce' );
/*
* Use get_post_meta() to retrieve an existing value
* from the database and use the value for the form.
*/
$value = get_post_meta( $post->ID, '_my_meta_value_key', true );
echo '<label for="myplugin_new_field">';
_e( 'Description for this field', 'myplugin_textdomain' );
echo '</label> ';
echo '<input type="text" id="myplugin_new_field" name="myplugin_new_field" value="' . esc_attr( $value ) . '" size="25" />';
}
/**
* When the post is saved, saves our custom data.
*
* @param int $post_id The ID of the post being saved.
*/
function myplugin_save_meta_box_data( $post_id ) {
/*
* We need to verify this came from our screen and with proper authorization,
* because the save_post action can be triggered at other times.
*/
// Check if our nonce is set.
if ( ! isset( $_POST['myplugin_meta_box_nonce'] ) ) {
return;
}
// Verify that the nonce is valid.
if ( ! wp_verify_nonce( $_POST['myplugin_meta_box_nonce'], 'myplugin_save_meta_box_data' ) ) {
return;
}
// If this is an autosave, our form has not been submitted, so we don't want to do anything.
if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
return;
}
// Check the user's permissions.
if ( isset( $_POST['post_type'] ) && 'page' == $_POST['post_type'] ) {
if ( ! current_user_can( 'edit_page', $post_id ) ) {
return;
}
} else {
if ( ! current_user_can( 'edit_post', $post_id ) ) {
return;
}
}
/* OK, it's safe for us to save the data now. */
// Make sure that it is set.
if ( ! isset( $_POST['myplugin_new_field'] ) ) {
return;
}
// Sanitize user input.
$my_data = sanitize_text_field( $_POST['myplugin_new_field'] );
// Update the meta field in the database.
update_post_meta( $post_id, '_my_meta_value_key', $my_data );
}
add_action( 'save_post', 'myplugin_save_meta_box_data' );
<?php
// Do NOT include the opening php tag
// Combine with conditionals maybe! http://cobaltapps.com/forum/forum/main-category/web-design-talk/74915-additional-meta-boxes http://themefoundation.com/wordpress-meta-boxes-guide/ http://wptheming.com/2010/08/custom-metabox-for-post-type/
<?php
// Retrieves the stored value from the database - put in hook box and choose hook location
$meta_value = get_post_meta( get_the_ID(), '_my_meta_value_key', true );
// Checks and displays the retrieved value
if( !empty( $meta_value ) ) {
echo $meta_value;
}
?>