Add multilingual support for success messages (#72)

* Remove bad comment

* Filter success message in class-wplf-polylang.php

* Pass language with front end requests

* Conform to CS

* Check that Polylang exists

* Fix phpcs errors after wpcs update

Author: k1sul1

assets/scripts/wplf-form.js

@@ -15,6 +15,10 @@
     submitHandler: function (e) {
       var form = e.target;
       var data = new FormData(form);
+
+      // Pass language if it exists.
+      ajax_object.lang && data.append('lang', ajax_object.lang);
+
       // add class to enable css changes to indicate ajax loading
       form.classList.add("sending");
 

classes/class-cpt-wplf-form.php

@@ -423,7 +423,9 @@ function save_cpt( $post_id ) {
 
     // save success message
     if ( isset( $_POST['wplf_thank_you'] ) ) {
-      update_post_meta( $post_id, '_wplf_thank_you', wp_kses_post( $_POST['wplf_thank_you'] ) );
+      $success = wp_kses_post( $_POST['wplf_thank_you'] );
+      $success = apply_filters( 'wplf_save_success_message', $success, $post_id );
+      update_post_meta( $post_id, '_wplf_thank_you', $success );
     }
 
     // save fields
@@ -587,10 +589,10 @@ function maybe_enqueue_frontend_script() {
     );
 
     // add dynamic variables to the script's scope
-    wp_localize_script( 'wplf-form-js', 'ajax_object', array(
+    wp_localize_script( 'wplf-form-js', 'ajax_object', apply_filters( 'wplf_ajax_object', array(
       'ajax_url' => admin_url( 'admin-ajax.php' ),
       'ajax_credentials' => apply_filters( 'wplf_ajax_fetch_credentials_mode', 'same-origin' ),
-    ) );
+    ) ) );
   }
 
 

classes/class-wplf-polylang.php

@@ -1,9 +1,7 @@
 <?php
 if ( ! class_exists( 'WPLF_Polylang' ) ) {
   class WPLF_Polylang {
-    /**
-     * CPT for the forms
-     */
+
     public static $instance;
     protected $regular_expression = "/{{[^{}\n]+}}/";
     protected $strings = array();
@@ -23,6 +21,11 @@ public function __construct() {
       add_filter( 'save_post_wplf-form', array( $this, 'save_form' ), 10, 3 );
       add_action( 'after_setup_theme', array( $this, 'register_strings' ) );
 
+      // Earlier than default. User probably wants to filter the translated message.
+      add_action( 'wplf_success_message', array( $this, 'render_success_message' ), 9 );
+      add_action( 'wplf_save_success_message', array( $this, 'save_success_message' ) );
+      add_action( 'wplf_ajax_object', array( $this, 'ajax_object' ) );
+
       $this->strings = get_option( 'wplf-translation-strings', array() );
       $this->register_strings();
     }
@@ -55,6 +58,39 @@ function save_form( $post_id, $post, $update ) {
       update_option( 'wplf-translation-strings', $this->strings ); // Let's be optimistic.
     }
 
+    public function render_success_message( $message ) {
+      // Get all strings inside double curly braces.
+      preg_match_all( $this->regular_expression, $message, $matches );
+      foreach ( $matches[0] as $match ) {
+        // match contains the braces, get rid of them.
+        $string = trim( str_replace( array( '{', '}' ), array( '', '' ), $match ) );
+        $message = str_replace( $match, $this->translate_string( $string ), $message );
+      }
+
+      return $message;
+    }
+
+    public function save_success_message( $message ) {
+      preg_match_all( $this->regular_expression, $message, $matches );
+      if ( ! empty( $matches ) ) {
+        foreach ( $matches[0] as $match ) {
+          // match contains the braces, get rid of them.
+          $string = trim( str_replace( array( '{', '}' ), array( '', '' ), $match ) );
+          $this->strings[ $string ] = null;
+          // By storing the string as the array key, we don't need to use array_unique.
+        }
+      }
+
+      update_option( 'wplf-translation-strings', $this->strings ); // Let's be optimistic.
+
+      return $message;
+    }
+
+    public function ajax_object( $array ) {
+      $array['lang'] = pll_current_language();
+      return $array;
+    }
+
     public function register_strings() {
       foreach ( $this->strings as $string => $value ) {
         $this->register_string( $string );

inc/wplf-ajax.php

@@ -81,8 +81,13 @@ function wplf_ajax_submit_handler() {
     $return->submission_title = $post_title;
     $return->form_id = $form->ID;
 
+    $success = get_post_meta( $form->ID, '_wplf_thank_you', true );
+    $success = apply_filters( "wplf_{$form->post_name}_success_message", $success );
+    $success = apply_filters( "wplf_{$form->ID}_success_message", $success );
+    $success = apply_filters( 'wplf_success_message', $success );
+
     // return the success message for the form
-    $return->success = apply_filters( 'the_content', get_post_meta( $form->ID, '_wplf_thank_you', true ) );
+    $return->success = $success;
 
     // allow user to attach custom actions after the submission has been received
     // these could be confirmation emails, additional processing for the submission fields, e.g.

wp-libre-form.php

@@ -88,7 +88,7 @@ public static function load_our_textdomain() {
    * Enable Polylang support
    */
   public function init_polylang_support() {
-    if ( apply_filters( 'wplf_load_polylang', true ) ) {
+    if ( apply_filters( 'wplf_load_polylang', true ) && class_exists( 'Polylang ' ) ) {
       require_once 'classes/class-wplf-polylang.php';
       WPLF_Polylang::init();
     }