Metabox Vendor ID 1

class sqpp_title_replacement {

	public function __construct() {

		if ( is_admin() ) {
			add_action( 'load-post.php',     array( $this, 'init_metabox' ) );
			add_action( 'load-post-new.php', array( $this, 'init_metabox' ) );
		}

	}

	public function init_metabox() {

		add_action( 'add_meta_boxes',        array( $this, 'add_metabox' )         );
		add_action( 'save_post',             array( $this, 'save_metabox' ), 10, 2 );

	}

	public function add_metabox() {

		add_meta_box(
			'sqpptitlereplacement',
			__( 'Title Replacement', 'sqppcptmeta' ),
			array( $this, 'render_sqpptitlereplacement' ),
			'page',
			'normal',
			'low'
		);

	}

	public function render_sqpptitlereplacement( $post ) {

		// Add nonce for security and authentication.
		wp_nonce_field( 'nonce_action', 'nonce' );

		// Retrieve an existing value from the database.
		$sqpptitlereplacetext = get_post_meta( $post->ID, 'sqpptitlereplacetext', true );
		$sqpptitlereplacement_yn = get_post_meta( $post->ID, 'sqpptitlereplacement_yn', true );
		$sqpptitlereplacetxtarea = get_post_meta( $post->ID, 'sqpptitlereplacetxtarea', true );

		// Set default values.
		if( empty( $sqpptitlereplacetext ) ) $sqpptitlereplacetext = '';
		if( empty( $sqpptitlereplacement_yn ) ) $sqpptitlereplacement_yn = array();
		if( empty( $sqpptitlereplacetxtarea ) ) $sqpptitlereplacetxtarea = '';

		// Form fields.
		echo '<table class="form-table">';

		echo '	<tr>';
		echo '		<th><label for="sqpptitlereplacetext" class="sqpptitlereplacetext_label">' . __( 'Title Replacement', 'sqppcptmeta' ) . '</label></th>';
		echo '		<td>';
		echo '			<input type="text" id="sqpptitlereplacetext" name="sqpptitlereplacetext" class="sqpptitlereplacetext_field" placeholder="' . esc_attr__( '', 'sqppcptmeta' ) . '" value="' . esc_attr( $sqpptitlereplacetext ) . '">';
		echo '		</td>';
		echo '	</tr>';

		echo '	<tr>';
		echo '		<th><label for="sqpptitlereplacement_yn" class="sqpptitlereplacement_yn_label">' . __( 'Replace Title', 'sqppcptmeta' ) . '</label></th>';
		echo '		<td>';
		echo '			<label><input type="checkbox" name="sqpptitlereplacement_yn[]" class="sqpptitlereplacement_yn_field" value="' . esc_attr( '' ) . '" ' . ( in_array( '', $sqpptitlereplacement_yn )? 'checked="checked"' : '' ) . '> ' . __( '', 'sqppcptmeta' ) . '</label><br>';
		echo '			<p class="description">' . __( 'Do you want to replace the title? If so, then add a text in the field below.', 'sqppcptmeta' ) . '</p>';
		echo '		</td>';
		echo '	</tr>';

		echo '	<tr>';
		echo '		<th><label for="sqpptitlereplacetxtarea" class="sqpptitlereplacetxtarea_label">' . __( 'Textarea', 'sqppcptmeta' ) . '</label></th>';
		echo '		<td>';
		echo '			<textarea id="sqpptitlereplacetxtarea" name="sqpptitlereplacetxtarea" class="sqpptitlereplacetxtarea_field" placeholder="' . esc_attr__( '', 'sqppcptmeta' ) . '">' . $sqpptitlereplacetxtarea . '</textarea>';
		echo '		</td>';
		echo '	</tr>';

		echo '</table>';

	}

	public function save_metabox( $post_id, $post ) {

		// Add nonce for security and authentication.
		$nonce_name   = isset( $_POST['nonce'] ) ? $_POST['nonce'] : '';
		$nonce_action = 'nonce_action';

		// Check if a nonce is set.
		if ( ! isset( $nonce_name ) )
			return;

		// Check if a nonce is valid.
		if ( ! wp_verify_nonce( $nonce_name, $nonce_action ) )
			return;

		// Check if the user has permissions to save data.
		if ( ! current_user_can( 'edit_post', $post_id ) )
			return;

		// Check if it's not an autosave.
		if ( wp_is_post_autosave( $post_id ) )
			return;

		// Check if it's not a revision.
		if ( wp_is_post_revision( $post_id ) )
			return;

		// Sanitize user input.
		$new_sqpptitlereplacetext = isset( $_POST[ 'sqpptitlereplacetext' ] ) ? sanitize_text_field( $_POST[ 'sqpptitlereplacetext' ] ) : '';
		$new_sqpptitlereplacement_yn = isset( $_POST[ 'sqpptitlereplacement_yn' ] ) ? array_intersect( (array) $_POST[ 'sqpptitlereplacement_yn' ], array( '' ) )  : array();
		$new_sqpptitlereplacetxtarea = isset( $_POST[ 'sqpptitlereplacetxtarea' ] ) ? sanitize_text_field( $_POST[ 'sqpptitlereplacetxtarea' ] ) : '';

		// Update the meta field in the database.
		update_post_meta( $post_id, 'sqpptitlereplacetext', $new_sqpptitlereplacetext );
		update_post_meta( $post_id, 'sqpptitlereplacement_yn', $new_sqpptitlereplacement_yn );
		update_post_meta( $post_id, 'sqpptitlereplacetxtarea', $new_sqpptitlereplacetxtarea );

	}

}

new sqpp_title_replacement;