Add dismissible donation callout

Author: Clorith

includes/class-string-locator.php

@@ -55,6 +55,68 @@ public function init() {
 		add_filter( 'plugin_row_meta', array( $this, 'plugin_row_meta' ), 10, 2 );
 
 		add_filter( 'string_locator_search_sources_markup', array( $this, 'add_search_options' ), 10, 2 );
+		add_action( 'wp_ajax_string_locator_notice_dismiss', array( $this, 'dismiss_notice' ) );
+
+		add_action( 'admin_notices', array( $this, 'show_sponsorship_notice' ) );
+	}
+
+	public function dismiss_notice() {
+		// Only users who can use the plugin should be able to dismiss the notice.
+		if ( ! current_user_can( 'update_core' ) || ! wp_verify_nonce( $_POST['_nonce'], 'string-locator-notice-dismiss' ) ) {
+			return;
+		}
+
+		update_option( 'string-locator-sponsorship-notice-dismissed', array( 'is_dismissed' => true ) );
+	}
+
+	public function show_sponsorship_notice() {
+		$screen = get_current_screen();
+
+		// Only show the notice on the plugins search page.
+		if ( 'tools_page_string-locator' !== $screen->id || isset( $_GET['edit-file'] ) ) {
+			return;
+		}
+
+		// Do not show the notice to users who have dismissed it.
+		$option = get_option( 'string-locator-sponsorship-notice-dismissed', array( 'is_dismissed' => false ) );
+		if ( true === $option['is_dismissed'] ) {
+			return;
+		}
+
+		?>
+
+		<div class="notice notice-info is-dismissible" id="string-locator-sponsorship-notice">
+			<p>
+				<?php esc_html_e( 'Thank you for trying out the String Locator plugin!', 'string-locator' ); ?>
+			</p>
+
+			<p>
+				<?php esc_html_e( 'If you like the plugin, please consider making a donation to support the plugin development.', 'string-locator' ); ?>
+			</p>
+
+			<p>
+				<a href="https://github.com/sponsors/Clorith/" target="_blank" class="button button-primary">
+					<?php esc_html_e( 'Donate via GitHub', 'string-locator' ); ?>
+				</a>
+
+				<a href="https://paypal.me/clorith" target="_blank" class="button">
+					<?php esc_html_e( 'Donate via PayPal', 'string-locator' ); ?>
+				</a>
+			</p>
+
+			<script>
+				jQuery( document ).ready( function( $ ) {
+					$( '#string-locator-sponsorship-notice' ).on( 'click', '.notice-dismiss', function() {
+						$.post( ajaxurl, {
+							action: 'string_locator_notice_dismiss',
+							_nonce: '<?php echo wp_create_nonce( 'string-locator-notice-dismiss' ); ?>'
+						} );
+					} );
+				} );
+			</script>
+		</div>
+
+		<?php
 	}
 
 	public function add_search_options( $searchers, $search_location ) {