Allow to add custom preferences to config.xml

wp-appkit/lib/simulator/config-file.php

@@ -444,6 +444,20 @@ protected static function get_icons_and_splashscreens_xml( $app_id, $app_platfor
 		return $app_icons_and_splashscreens_files;
 	}
 
+	protected static function get_custom_preferences( $app_id, $app_platform, $export_type ) {
+		/**
+		 * 'wpak_config_xml_custom_preferences' filter. 
+		 * Allows to add custom preferences to config.xml file.
+		 * (This filters only applies to non PWA exports).
+		 * 
+		 * @param array     custom preferences to add: array of [ 'name' => 'preferenceName', 'value' => 'preferenceValue' ]
+		 * @param int       $app_id         Application ID.
+	 	 * @param string    $app_platform   App platform (see WpakApps::get_platforms to get the list).
+	 	 * @param string    $export_type    Export type.
+		 */
+		return apply_filters( 'wpak_config_xml_custom_preferences', [], $app_id, $app_platform, $export_type );
+	}
+
 	public static function get_config_xml( $app_id, $echo = false, $export_type = 'phonegap-build' ) {
 
 		$app_main_infos = WpakApps::get_app_main_infos( $app_id );
@@ -464,6 +478,9 @@ public static function get_config_xml( $app_id, $echo = false, $export_type = 'p
 		$whitelist_settings = self::get_whitelist_settings( $app_id, $app_platform, $export_type );
 		$splashscreen_settings = self::get_splashscreen_settings( $app_id, $app_platform, $export_type );
 
+		//Custom preferences (added via hook):
+		$custom_preferences = self::get_custom_preferences( $app_id, $app_platform, $export_type );
+
 		//Merge our default Phonegap Build plugins to those set in BO :
 		$app_phonegap_plugins = WpakApps::get_merged_phonegap_plugins_xml( $app_id, $export_type, $app_main_infos['phonegap_plugins'] );
 
@@ -518,6 +535,13 @@ public static function get_config_xml( $app_id, $echo = false, $export_type = 'p
 	<preference name="webviewbounce" value="false" />
 <?php endif ?>
 
+	<!-- Custom preferences -->
+<?php if( !empty( $custom_preferences ) ) : ?>
+<?php foreach( $custom_preferences as $preference ): ?>
+	<preference name="<?php echo esc_attr( $preference['name'] ); ?>" value="<?php echo esc_attr( $preference['value'] ); ?>" />
+<?php endforeach ?>
+<?php endif ?>
+
 	<!-- PhoneGap plugin declaration -->
 <?php if( !empty( $app_phonegap_plugins ) ): ?>
 	<?php echo str_replace( "\n", "\n\t", $app_phonegap_plugins ) ?>