Adding A Post Metabox

Adds a basic metabox on your post screen

This first snippet just declares the box and where it should appear

function my_new_box() {

    $screens = array( 'post', 'page' );                  // this is the post type that the box will appear on (post,page,custom post type) separated by commas

    foreach ( $screens as $screen ) {  // 1122AM

      add_meta_box( 
          'my_new_box',                           // the id of the div that controls the meta box. Case you want to style it
          __( 'My New Box', 'studio2108.com' ),   // little title that appears in the meta box in the editor
          'my_new_box_content',                   // this is the function that prints the HTML out
          $screen,                                // this is the post type that the box will appear on (post,page,custom post type)
          'normal',                               // puts the box under the editor // sometimes I use "side" for side boxes
          'high'                                  // places it first under the editor
      );

   } // 1122AM
}
add_action( 'add_meta_boxes', 'my_new_box' );

This second snippet puts the fields in the box

function my_new_box_content( $post ) { //926AM
	
	wp_nonce_field( plugin_basename( __FILE__ ), 'my_new_box_nonce' ); // sets my hidden NONCE field data

        $this_post_id= $post->ID;

        $new_box_text_field = get_post_meta( $this_post_id, 'new_box_text_field', true );
        $new_box_textarea = get_post_meta( $this_post_id, 'new_box_textarea', true );
        $new_box_select = get_post_meta( $this_post_id, 'new_box_select', true );
        $new_box_checkbox = get_post_meta( $this_post_id, 'new_box_checkbox', true );

 ?>
       <label>new box text field</label>
       <input type="text" name="new_box_text_field" class="new_box_text_field" value="<? echo stripslashes($new_box_text_field); ?>">

       <label>new_box_textarea</label>
       <textarea name="new_box_textarea"><? echo stripslashes(echo $new_box_textarea); ?></textarea>

       <label>new_box_select</label>
       <select name="new_box_select">
       <option value="<?php echo stripslashes($new_box_select); ?>"><?php echo stripslashes($new_box_select); ?></option>
       <option value=""></option>
       <option value="something_1">something_1</option>
       <option value="something_1">something_1</option>
       </select>

       <label>new_box_checkbox</label>
       <input type="checkbox" name="new_box_checkbox" value="yes">

<?
} //926AM 

This last part is the “catcher” of the input from your added box. It basically saves what you enter in the meta box.

function my_new_box_save( $post_id ) { // 847AM

	if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) // this stops auto save from updating my fields automatically
	return;

	if ( !wp_verify_nonce( $_POST['my_new_box_nonce'], plugin_basename( __FILE__ ) ) )  // checks the nonce on the save
	return;

	update_post_meta( $post_id, 'new_box_text_field', $_POST['new_box_text_field'] );
	update_post_meta( $post_id, 'new_box_textarea', $_POST['new_box_textarea'] );
	update_post_meta( $post_id, 'new_box_select', $_POST['new_box_select'] );
	update_post_meta( $post_id, 'new_box_checkbox', $_POST['new_box_checkbox'] );

} // 847AM


add_action( 'save_post', 'my_new_box_save' );